柚子快报邀请码778899分享：四则运算APP版
（一）四则运算APP版
这这个Demo的目的就是强化一下本周学习的Android的Jetpack里的新内容，接下来我将通过这个Demo来展示我所学到的新知识。
先列出新学到的知识：ViewModel，Navigation，MutableLiveData，ViewModelSaveState,SharedPreferences,AndroidViewModel,DataBinding
设计思路：
UI设计思路：
一共四个页面：首页，习题页，成功页，失败页
将这四个页面通过Navigation连接起来形成一条逻辑关系。
接下来就是对每个页面进行设计。
首页：一个TextView和一个ImageView还有一个Button，顶部还有一个最高分Textview，通过button来进入出题页面
xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools"> name="data" type="com.example.calculation.MyViewModel" /> android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".TitleFragment"> android:id="@+id/guideline" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="vertical" app:layout_constraintGuide_percent="0.1" /> android:id="@+id/guideline2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="vertical" app:layout_constraintGuide_percent="0.9" /> android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/CalName" android:textSize="@dimen/huge_size" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toStartOf="@+id/guideline2" app:layout_constraintStart_toStartOf="@+id/guideline" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.106" /> android:id="@+id/imageView" android:layout_width="320dp" android:layout_height="349dp" android:contentDescription="@string/title_image" android:src="@drawable/size" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintDimensionRatio="w,1:1" app:layout_constraintEnd_toStartOf="@+id/guideline2" app:layout_constraintHorizontal_bias="0.56" app:layout_constraintStart_toStartOf="@+id/guideline" app:layout_constraintTop_toTopOf="parent" /> android:id="@+id/button" android:layout_width="0dp" android:layout_height="wrap_content" android:text="@string/title_button" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toStartOf="@+id/guideline2" app:layout_constraintHorizontal_bias="0.0" app:layout_constraintStart_toStartOf="@+id/guideline" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.862" /> android:id="@+id/textView2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@{@string/higer_score(data.highScore)}" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.883" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.036" tools:text="High Score:%d" />
View Code
出题页面：顶部一个textview代表目前的得分情况，中间是一个算式，下面是你的答案，接下来是4行3列，12个按钮代表你的操作。
xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools"> name="data" type="com.example.calculation.MyViewModel" /> android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".QuestionFragment"> android:id="@+id/guideline3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.1" /> android:id="@+id/guideline4" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.2" /> android:id="@+id/guideline5" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.33" /> android:id="@+id/guideline6" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.4" /> android:id="@+id/guideline10" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.5" /> android:id="@+id/guideline11" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.6" /> android:id="@+id/guideline12" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.7" /> android:id="@+id/guideline7" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.8" /> android:id="@+id/textView3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@{@string/Current_Score(data.currentScore)}" app:layout_constraintBottom_toTopOf="@+id/guideline3" app:layout_constraintEnd_toStartOf="@+id/guideline9" app:layout_constraintHorizontal_bias="0.537" app:layout_constraintStart_toStartOf="@+id/guideline8" app:layout_constraintTop_toTopOf="@+id/guideline3" app:layout_constraintVertical_bias="0.473" tools:text="Score:0" /> android:id="@+id/guideline8" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="vertical" app:layout_constraintGuide_percent="0.1" /> android:id="@+id/guideline9" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="vertical" app:layout_constraintGuide_percent="0.9" /> android:id="@+id/textView4" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="@dimen/huge_size" android:text="@{String.valueOf(data.leftNumber)}" app:layout_constraintBottom_toBottomOf="@+id/textView5" app:layout_constraintEnd_toStartOf="@+id/textView5" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toStartOf="@+id/guideline8" app:layout_constraintTop_toTopOf="@+id/textView5" tools:text="1" /> android:id="@+id/textView5" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="@dimen/huge_size" android:text="@{String.valueOf(data.operator)}" app:layout_constraintBottom_toBottomOf="@+id/textView6" app:layout_constraintEnd_toStartOf="@+id/textView6" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/textView4" app:layout_constraintTop_toTopOf="@+id/textView6" tools:text="+" /> android:id="@+id/textView6" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="@dimen/huge_size" android:text="@{String.valueOf(data.rigthNumber)}" app:layout_constraintBottom_toBottomOf="@+id/textView7" app:layout_constraintEnd_toStartOf="@+id/textView7" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/textView5" app:layout_constraintTop_toTopOf="@+id/textView7" tools:text="2" /> android:id="@+id/textView7" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="=" android:textSize="@dimen/huge_size" app:layout_constraintBottom_toBottomOf="@+id/textView8" app:layout_constraintEnd_toStartOf="@+id/textView8" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/textView6" app:layout_constraintTop_toTopOf="@+id/textView8" tools:text="=" /> android:id="@+id/textView8" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/Cal_Answer" android:textSize="@dimen/huge_size" app:layout_constraintBottom_toTopOf="@+id/guideline4" app:layout_constraintEnd_toStartOf="@+id/guideline9" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/textView7" app:layout_constraintTop_toTopOf="@+id/guideline4" /> android:id="@+id/textView9" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Your Answer:" android:textSize="@dimen/mid_size" app:layout_constraintBottom_toTopOf="@+id/guideline5" app:layout_constraintEnd_toStartOf="@+id/guideline9" app:layout_constraintStart_toStartOf="@+id/guideline8" app:layout_constraintTop_toTopOf="@+id/guideline5" /> android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="1" android:textSize="@dimen/button_size" app:layout_constraintBottom_toTopOf="@+id/guideline10" app:layout_constraintEnd_toStartOf="@+id/button2" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toStartOf="@+id/guideline8" app:layout_constraintTop_toTopOf="@+id/guideline6" /> android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="2" android:textSize="@dimen/button_size" app:layout_constraintBottom_toBottomOf="@+id/button1" app:layout_constraintEnd_toStartOf="@+id/button3" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/button1" app:layout_constraintTop_toTopOf="@+id/button1" /> android:id="@+id/button3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="3" android:textSize="@dimen/button_size" app:layout_constraintBottom_toBottomOf="@+id/button2" app:layout_constraintEnd_toStartOf="@+id/guideline9" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/button2" app:layout_constraintTop_toTopOf="@+id/button2" /> android:id="@+id/button4" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="4" android:textSize="@dimen/button_size" app:layout_constraintBottom_toTopOf="@+id/guideline11" app:layout_constraintEnd_toStartOf="@+id/button5" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toStartOf="@+id/guideline8" app:layout_constraintTop_toTopOf="@+id/guideline10" /> android:id="@+id/button5" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="5" android:textSize="@dimen/button_size" app:layout_constraintBottom_toBottomOf="@+id/button4" app:layout_constraintEnd_toStartOf="@+id/button6" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/button4" app:layout_constraintTop_toTopOf="@+id/button4" /> android:id="@+id/button6" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="6" android:textSize="@dimen/button_size" app:layout_constraintBottom_toBottomOf="@+id/button5" app:layout_constraintEnd_toStartOf="@+id/guideline9" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/button5" app:layout_constraintTop_toTopOf="@+id/button5" /> android:id="@+id/button7" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="7" android:textSize="@dimen/button_size" app:layout_constraintBottom_toTopOf="@+id/guideline12" app:layout_constraintEnd_toStartOf="@+id/button8" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toStartOf="@+id/guideline8" app:layout_constraintTop_toTopOf="@+id/guideline11" /> android:id="@+id/button8" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="8" android:textSize="@dimen/button_size" app:layout_constraintBottom_toBottomOf="@+id/button7" app:layout_constraintEnd_toStartOf="@+id/button9" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/button7" app:layout_constraintTop_toTopOf="@+id/button7" /> android:id="@+id/button9" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="9" android:textSize="@dimen/button_size" app:layout_constraintBottom_toBottomOf="@+id/button8" app:layout_constraintEnd_toStartOf="@+id/guideline9" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/button8" app:layout_constraintTop_toTopOf="@+id/button8" /> android:id="@+id/clear" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Clear" android:textSize="@dimen/button_size" app:layout_constraintBottom_toTopOf="@+id/guideline7" app:layout_constraintEnd_toStartOf="@+id/button0" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toStartOf="@+id/guideline8" app:layout_constraintTop_toTopOf="@+id/guideline12" /> android:id="@+id/button0" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="0" android:textSize="@dimen/button_size" app:layout_constraintBottom_toBottomOf="@+id/clear" app:layout_constraintEnd_toStartOf="@+id/submit" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/clear" app:layout_constraintTop_toTopOf="@+id/clear" /> android:id="@+id/submit" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="OK" android:textSize="@dimen/button_size" app:layout_constraintBottom_toBottomOf="@+id/button0" app:layout_constraintEnd_toStartOf="@+id/guideline9" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toEndOf="@+id/button0" app:layout_constraintTop_toTopOf="@+id/button0" />
View Code
成功页面：一个Imageview笑脸，两个Textview还有一个Button来返回首页
xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools"> name="data" type="com.example.calculation.MyViewModel" /> android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".WinFragment"> android:id="@+id/guideline13" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.1" /> android:id="@+id/guideline14" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.35" /> android:id="@+id/imageView2" android:layout_width="0dp" android:layout_height="0dp" android:contentDescription="@string/image_win" android:src="@drawable/ic_sentiment_satisfied_black_24dp" app:layout_constraintBottom_toTopOf="@+id/guideline14" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="@+id/guideline13" /> android:id="@+id/textView10" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="恭喜你！创下新纪录" android:textSize="@dimen/bige_size" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="@+id/guideline14" app:layout_constraintVertical_bias="0.1" /> android:id="@+id/textView11" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@{@string/New_Score(data.highScore)}" android:textSize="@dimen/bige_size" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/imageView2" app:layout_constraintVertical_bias="0.3" tools:text="你的成绩是:%d" /> android:id="@+id/button10" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="返回" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.498" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="@+id/guideline14" app:layout_constraintVertical_bias="0.5" />
View Code
失败页面：一个Imageview哭脸，两个Textview还有一个Button来返回首页
xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools"> name="data" type="com.example.calculation.MyViewModel" /> android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".LoseFragment"> android:id="@+id/guideline15" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.1" /> android:id="@+id/guideline16" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintGuide_percent="0.35" /> android:id="@+id/imageView3" android:layout_width="0dp" android:layout_height="0dp" android:src="@drawable/ic_sentiment_dissatisfied_black_24dp" app:layout_constraintBottom_toTopOf="@+id/guideline16" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="@+id/guideline15" /> android:id="@+id/textView13" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@{@string/New_Score(data.currentScore)}" android:textSize="@dimen/bige_size" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="@+id/guideline16" app:layout_constraintVertical_bias="0.3" tools:text="你的成绩是:%d" /> android:id="@+id/button11" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="返回" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.498" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="@+id/guideline16" app:layout_constraintVertical_bias="0.5" /> android:id="@+id/textView14" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="挑战失败!" android:textSize="@dimen/bige_size" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/imageView3" app:layout_constraintVertical_bias="0.1" />
View Code
程序设计：
首先是设计我们的MyViewModel里的数据，有最高分，目前得分，左操作数，右操作数，操作符，答案
通过SharedPreferences来保存数据，livedata可以随时的刷新数据，故用它来显示数据。
package com.example.calculation;
import android.app.Application;
import android.content.Context;
import android.content.SharedPreferences;
import androidx.annotation.NonNull;
import androidx.lifecycle.AndroidViewModel;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.SavedStateHandle;
import androidx.lifecycle.ViewModel;
import java.util.Random;
public class MyViewModel extends AndroidViewModel {
private SavedStateHandle handle;
private static String KEY_HIGH_SCORE="key_high_score";
private static String KEY_LEFT_NUMBER="key_left_number";
private static String KEY_RIGHT_NUMBER="key_right_number";
private static String KEY_OPERATOR="key_operator";
private static String KEY_ANSWER="key_answer";
private static String SAVE_SHP_DATA_NAME="save_shp_data_name";
private static String KEY_CURRENT_SCORE="key_current_score";
public boolean win_flag=false;
public MyViewModel(@NonNull Application application,SavedStateHandle handle) {
super(application);
if(!handle.contains(KEY_HIGH_SCORE)){
SharedPreferences shp=getApplication().getSharedPreferences(SAVE_SHP_DATA_NAME, Context.MODE_PRIVATE);
handle.set(KEY_HIGH_SCORE,shp.getInt(KEY_HIGH_SCORE,0));
handle.set(KEY_LEFT_NUMBER,0);
handle.set(KEY_RIGHT_NUMBER,0);
handle.set(KEY_OPERATOR,"+");
handle.set(KEY_ANSWER,0);
handle.set(KEY_CURRENT_SCORE,0);
}
this.handle=handle;
}
public MutableLiveData
return handle.getLiveData(KEY_LEFT_NUMBER);
}
public MutableLiveData
return handle.getLiveData(KEY_RIGHT_NUMBER);
}
public MutableLiveData
return handle.getLiveData(KEY_OPERATOR);
}
public MutableLiveData
return handle.getLiveData(KEY_HIGH_SCORE);
}
public MutableLiveData
return handle.getLiveData(KEY_CURRENT_SCORE);
}
public MutableLiveData
return handle.getLiveData(KEY_ANSWER);
}
public void setCurrentScore(){
handle.set(KEY_CURRENT_SCORE,0);
}
void generator(){
int level=100;
Random random=new Random();
int a=random.nextInt(level)+1;
int b=random.nextInt(level)+1;
if(a%4==0){
getOperator().setValue("+");
if(a>b){
getAnswer().setValue(a);
getLeftNumber().setValue(b);
getRigthNumber().setValue(a-b);
}else{
getOperator().setValue("+");
getAnswer().setValue(b);
getLeftNumber().setValue(a);
getRigthNumber().setValue(b-a);
}
}
else if(a%4==1){
getOperator().setValue("-");
if(a>b){
getAnswer().setValue(a-b);
getLeftNumber().setValue(a);
getRigthNumber().setValue(b);
}else{
getOperator().setValue("-");
getAnswer().setValue(b-a);
getLeftNumber().setValue(b);
getRigthNumber().setValue(a);
}
}
else if(a%4==2){
getOperator().setValue("*");
getLeftNumber().setValue(a);
getRigthNumber().setValue(b);
getAnswer().setValue(a*b);
}
else if(a%4==3){
getOperator().setValue("/");
while(a%b!=0){
a=random.nextInt(level)+1;
b=random.nextInt(level)+1;
}
getLeftNumber().setValue(a);
getRigthNumber().setValue(b);
getAnswer().setValue(a/b);
}
}
void save(){
SharedPreferences shp=getApplication().getSharedPreferences(SAVE_SHP_DATA_NAME,Context.MODE_PRIVATE);
SharedPreferences.Editor editor=shp.edit();
editor.putInt(KEY_HIGH_SCORE,getHighScore().getValue());
editor.apply();
}
void answerCurrent(){
getCurrentScore().setValue(getCurrentScore().getValue()+1);
if(getCurrentScore().getValue()>getHighScore().getValue()){
getHighScore().setValue(getCurrentScore().getValue());
win_flag=true;
}
generator();
}
}
View Code
TieleFragment的设计：设计一个按钮的绑定事件，进行跳转到出题页面
package com.example.calculation;
import android.app.AppComponentFactory;
import android.app.Application;
import android.content.pm.ApplicationInfo;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.databinding.DataBindingUtil;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.SavedStateViewModelFactory;
import androidx.lifecycle.ViewModelProvider;
import androidx.lifecycle.ViewModelProviders;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.example.calculation.databinding.FragmentTitleBinding;
/**
* A simple {@link Fragment} subclass.
*/
public class TitleFragment extends Fragment{
public TitleFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(@NonNull LayoutInflater inflater, final ViewGroup container,
Bundle savedInstanceState) {
FragmentTitleBinding binding;
binding= DataBindingUtil.inflate(inflater,R.layout.fragment_title,container,false);
MyViewModel myViewModel = ViewModelProviders.of(requireActivity(), new SavedStateViewModelFactory(requireActivity().getApplication(),requireActivity())).get(MyViewModel.class);
binding.setData(myViewModel);
binding.setLifecycleOwner(requireActivity());
binding.button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
NavController controller=Navigation.findNavController(v);
controller.navigate(R.id.action_titleFragment_to_questionFragment);
}
});
return binding.getRoot();
// Inflate the layout for this fragment
//return inflater.inflate(R.layout.fragment_title, container, false);
}
}
View Code
QuestionFragment的设计：通过按钮点击来获取用户的答案，然后从数据里获取当前的viewmodel，判断结果是否相同，之后进行相应的操作。
里面有代码注释
package com.example.calculation;
import android.os.Bundle;
import androidx.databinding.DataBindingUtil;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.SavedStateViewModelFactory;
import androidx.lifecycle.ViewModelProvider;
import androidx.lifecycle.ViewModelProviders;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.example.calculation.databinding.FragmentQuestionBinding;
/**
* A simple {@link Fragment} subclass.
*/
public class QuestionFragment extends Fragment {
public QuestionFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, final ViewGroup container,
Bundle savedInstanceState) {
final MyViewModel myViewModel;
myViewModel= ViewModelProviders.of(requireActivity(),new SavedStateViewModelFactory(requireActivity().getApplication(),requireActivity())).get(MyViewModel.class);
//获取运算表达式
myViewModel.generator();
//设置初始得分为0
myViewModel.setCurrentScore();
//获取页面的控制binding
final FragmentQuestionBinding binding;
binding= DataBindingUtil.inflate(inflater,R.layout.fragment_question,container,false);
//设置数据与生命周期
binding.setData(myViewModel);
binding.setLifecycleOwner(requireActivity());
//builder用来保存用户输入的数据
final StringBuilder builder=new StringBuilder();
View.OnClickListener listener=new View.OnClickListener() {
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.button0:
builder.append(0);
break;
case R.id.button1:
builder.append(1);
break;
case R.id.button2:
builder.append(2);
break;
case R.id.button3:
builder.append(3);
break;
case R.id.button4:
builder.append(4);
break;
case R.id.button5:
builder.append(5);
break;
case R.id.button6:
builder.append(6);
break;
case R.id.button7:
builder.append(7);
break;
case R.id.button8:
builder.append(8);
break;
case R.id.button9:
builder.append(9);
break;
case R.id.clear:
//清楚代表用户的输入长度未0
builder.setLength(0);
break;
}
if(builder.length()==0){
binding.textView9.setText("请输入你的答案：");
}else{
//显示到UI页面上
binding.textView9.setText(builder.toString());
}
}
};
//设置每一个按钮的点击事件
binding.button0.setOnClickListener(listener);
binding.button1.setOnClickListener(listener);
binding.button2.setOnClickListener(listener);
binding.button3.setOnClickListener(listener);
binding.button4.setOnClickListener(listener);
binding.button5.setOnClickListener(listener);
binding.button6.setOnClickListener(listener);
binding.button7.setOnClickListener(listener);
binding.button8.setOnClickListener(listener);
binding.button9.setOnClickListener(listener);
binding.clear.setOnClickListener(listener);
//提交按钮的设计
binding.submit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(builder.length()!=0) {
//当答案相同时
if (Integer.valueOf(builder.toString()).intValue() == myViewModel.getAnswer().getValue()) {
myViewModel.answerCurrent();
builder.setLength(0);
binding.textView9.setText("回答正确! 请继续!");
} else {
NavController controller = Navigation.findNavController(v);
if (myViewModel.win_flag) {
//当创造新纪录时，进入成功页面
controller.navigate(R.id.action_questionFragment_to_winFragment);
myViewModel.win_flag = false;
myViewModel.save();
} else {
//否则进入失败页面
controller.navigate(R.id.action_questionFragment_to_loseFragment);
}
}
}else{
Toast.makeText(v.getContext(), "请输入答案", Toast.LENGTH_SHORT).show();
}
}
});
return binding.getRoot();
// Inflate the layout for this fragment
//return inflater.inflate(R.layout.fragment_question, container, false);
}
}
View Code
WinFragment的设计：设置它的返回按钮，与LoseFragment一样
package com.example.calculation;
import android.os.Bundle;
import androidx.databinding.DataBindingUtil;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.SavedStateHandle;
import androidx.lifecycle.SavedStateViewModelFactory;
import androidx.lifecycle.ViewModelProvider;
import androidx.lifecycle.ViewModelProviders;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.example.calculation.databinding.FragmentWinBinding;
/**
* A simple {@link Fragment} subclass.
*/
public class WinFragment extends Fragment {
public WinFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
MyViewModel myViewModel;
myViewModel= ViewModelProviders.of(requireActivity(), new SavedStateViewModelFactory(requireActivity().getApplication(),requireActivity())).get(MyViewModel.class);
FragmentWinBinding binding;
binding= DataBindingUtil.inflate(inflater,R.layout.fragment_win,container,false);
binding.setData(myViewModel);
binding.setLifecycleOwner(requireActivity());
binding.button10.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
NavController controller= Navigation.findNavController(v);
controller.navigate(R.id.action_winFragment_to_titleFragment);
}
});
return binding.getRoot();
// Inflate the layout for this fragment
//return inflater.inflate(R.layout.fragment_win, container, false);
}
}
View Code
package com.example.calculation;
import android.os.Bundle;
import androidx.databinding.DataBindingUtil;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.SavedStateViewModelFactory;
import androidx.lifecycle.ViewModelProvider;
import androidx.lifecycle.ViewModelProviders;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.example.calculation.databinding.FragmentLoseBinding;
/**
* A simple {@link Fragment} subclass.
*/
public class LoseFragment extends Fragment {
public LoseFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, final ViewGroup container,
Bundle savedInstanceState) {
MyViewModel myViewModel;
myViewModel= ViewModelProviders.of(requireActivity(),new SavedStateViewModelFactory(requireActivity().getApplication(),requireActivity())).get(MyViewModel.class);
FragmentLoseBinding binding;
binding= DataBindingUtil.inflate(inflater,R.layout.fragment_lose,container,false);
binding.setData(myViewModel);
binding.setLifecycleOwner(requireActivity());
binding.button11.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
NavController controller= Navigation.findNavController(v);
controller.navigate(R.id.action_loseFragment_to_titleFragment);
}
});
return binding.getRoot();
// Inflate the layout for this fragment
//return inflater.inflate(R.layout.fragment_lose, container, false);
}
}
View Code
MainActivity的设计：用来设置左上角的返回与手机左下方左三角的返回
package com.example.calculation;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.NavigationUI;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
NavController controller;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
controller= Navigation.findNavController(this,R.id.fragment);
NavigationUI.setupActionBarWithNavController(this,controller);
}
//设置页面的左上角的返回操作
@Override
public boolean onSupportNavigateUp() {
if(controller.getCurrentDestination().getId()==R.id.questionFragment){
AlertDialog.Builder builder=new AlertDialog.Builder(this);
builder.setTitle("你确定要退出吗？");
builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
controller.navigateUp();
}
});
builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
AlertDialog dialog=builder.create();
dialog.show();
}else{
controller.navigate(R.id.titleFragment);
}
return super.onSupportNavigateUp();
}
//设置手机的左三角的返回操作
@Override
public void onBackPressed() {
onSupportNavigateUp();
}
}
View Code
整个项目到此完结。。。花费时间：2020/3/29：上午10：00-11：10，休息10分钟，11：30-12：30，2020/3/29：下午15：00-15：45，吃东西喝水10分钟，16：00-19：00，吃饭30分钟。2020/3/29：晚上19：30-20：45，完成。共花费：420分钟，代码量：450行，UI设计代码除外。
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