冲刺十四天（实现好友页的排序展示）

实现好友页的字母排序展示

　　采用的一个汉字转汉语拼音的第三方库

implementation 'com.belerweb:pinyin4j:2.5.1'//转拼音

　　自定义一个sidebar布局文件来展示拼音

package com.example.newbsh.UI.friends.list;

import android.content.Context;

import android.content.res.TypedArray;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.util.AttributeSet;

import android.view.MotionEvent;

import android.widget.TextView;

import com.example.newbsh.R;

public class SideBar extends androidx.appcompat.widget.AppCompatTextView {

private String[] letters = new String[]{"A", "B", "C", "D", "E", "F", "G", "H", "I",

"J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",

"W", "X", "Y", "Z", "#"};

private Paint textPaint;

private Paint bigTextPaint;

private Paint scaleTextPaint;

private Canvas canvas;

private int itemH;

private int w;

private int h;

/**

* 普通情况下字体大小

*/

float singleTextH;

/**

* 缩放离原始的宽度

*/

private float scaleWidth;

/**

* 滑动的Y

*/

private float eventY = 0;

/**

* 缩放的倍数

*/

private int scaleSize = 1;

/**

* 缩放个数item，即开口大小

*/

private int scaleItemCount = 6;

private ISideBarSelectCallBack callBack;

public SideBar(Context context) {

this(context, null);

}

public SideBar(Context context, AttributeSet attrs) {

this(context, attrs, 0);

}

public SideBar(Context context, AttributeSet attrs, int defStyleAttr) {

super(context, attrs, defStyleAttr);

init(attrs);

}

private void init(AttributeSet attrs) {

if (attrs != null) {

TypedArray ta = getContext().obtainStyledAttributes(attrs, R.styleable.SideBar);

scaleSize = ta.getInteger(R.styleable.SideBar_scaleSize, 1);

scaleItemCount = ta.getInteger(R.styleable.SideBar_scaleItemCount, 6);

scaleWidth = ta.getDimensionPixelSize(R.styleable.SideBar_scaleWidth, dp(100));

ta.recycle();

}

textPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

textPaint.setColor(getCurrentTextColor());

textPaint.setTextSize(getTextSize());

textPaint.setTextAlign(Paint.Align.CENTER);

bigTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

bigTextPaint.setColor(getCurrentTextColor());

bigTextPaint.setTextSize(getTextSize() * (scaleSize + 3));

bigTextPaint.setTextAlign(Paint.Align.CENTER);

scaleTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

scaleTextPaint.setColor(getCurrentTextColor());

scaleTextPaint.setTextSize(getTextSize() * (scaleSize + 1));

scaleTextPaint.setTextAlign(Paint.Align.CENTER);

}

public void setDataResource(String[] data) {

letters = data;

invalidate();

}

public void setOnStrSelectCallBack(ISideBarSelectCallBack callBack) {

this.callBack = callBack;

}

/**

* 设置字体缩放比例

*

* @param scale

*/

public void setScaleSize(int scale) {

scaleSize = scale;

invalidate();

}

/**

* 设置缩放字体的个数，即开口大小

*

* @param scaleItemCount

*/

public void setScaleItemCount(int scaleItemCount) {

this.scaleItemCount = scaleItemCount;

invalidate();

}

private int dp(int px) {

final float scale = getContext().getResources().getDisplayMetrics().density;

return (int) (px * scale + 0.5f);

}

@Override

public boolean onTouchEvent(MotionEvent event) {

switch (event.getAction()) {

case MotionEvent.ACTION_DOWN:

case MotionEvent.ACTION_MOVE:

if (event.getX() > (w - getPaddingRight() - singleTextH - 10)) {

eventY = event.getY();

invalidate();

return true;

} else {

eventY = 0;

invalidate();

break;

}

case MotionEvent.ACTION_CANCEL:

eventY = 0;

invalidate();

return true;

case MotionEvent.ACTION_UP:

if (event.getX() > (w - getPaddingRight() - singleTextH - 10)) {

eventY = 0;

invalidate();

return true;

} else

break;

}

return super.onTouchEvent(event);

}

@Override

protected void onDraw(Canvas canvas) {

this.canvas = canvas;

DrawView(eventY);

}

private void DrawView(float y) {

int currentSelectIndex = -1;

if (y != 0) {

for (int i = 0; i < letters.length; i++) {

float currentItemY = itemH * i;

float nextItemY = itemH * (i + 1);

if (y >= currentItemY && y < nextItemY) {

currentSelectIndex = i;

if (callBack != null) {

callBack.onSelectStr(currentSelectIndex, letters[i]);

}

//画大的字母

Paint.FontMetrics fontMetrics = bigTextPaint.getFontMetrics();

float bigTextSize = fontMetrics.descent - fontMetrics.ascent;

canvas.drawText(letters[i], w - getPaddingRight() - scaleWidth - bigTextSize, singleTextH + itemH * i, bigTextPaint);

}

}

}

drawLetters(y, currentSelectIndex);

}

private void drawLetters(float y, int index) {

//第一次进来没有缩放情况，默认画原图

if (index == -1) {

w = getMeasuredWidth();

h = getMeasuredHeight();

itemH = h / letters.length;

Paint.FontMetrics fontMetrics = textPaint.getFontMetrics();

singleTextH = fontMetrics.descent - fontMetrics.ascent;

for (int i = 0; i < letters.length; i++) {

canvas.drawText(letters[i], w - getPaddingRight(), singleTextH + itemH * i, textPaint);

}

//触摸的时候画缩放图

} else {

//遍历所有字母

for (int i = 0; i < letters.length; i++) {

//要画的字母的起始Y坐标

float currentItemToDrawY = singleTextH + itemH * i;

float centerItemToDrawY;

if (index < i)

centerItemToDrawY = singleTextH + itemH * (index + scaleItemCount);

else

centerItemToDrawY = singleTextH + itemH * (index - scaleItemCount);

float delta = 1 - Math.abs((y - currentItemToDrawY) / (centerItemToDrawY - currentItemToDrawY));

float maxRightX = w - getPaddingRight();

//如果大于0，表明在y坐标上方

scaleTextPaint.setTextSize(getTextSize() + getTextSize() * delta);

float drawX = maxRightX - scaleWidth * delta;

//超出边界直接花在边界上

if (drawX > maxRightX)

canvas.drawText(letters[i], maxRightX, singleTextH + itemH * i, textPaint);

else

canvas.drawText(letters[i], drawX, singleTextH + itemH * i, scaleTextPaint);

}

}

}

public interface ISideBarSelectCallBack {

void onSelectStr(int index, String selectStr);

}

}

　　创建汉字转换位汉语拼音，英文字符不变的一个工具类

package com.example.newbsh.UI.friends.list;

import net.sourceforge.pinyin4j.PinyinHelper;

import net.sourceforge.pinyin4j.format.HanyuPinyinCaseType;

import net.sourceforge.pinyin4j.format.HanyuPinyinOutputFormat;

import net.sourceforge.pinyin4j.format.HanyuPinyinToneType;

/**

* 汉字转换位汉语拼音，英文字符不变

*/

public class Cn2Spell {

public static StringBuffer sb = new StringBuffer();

/**

* 获取汉字字符串的首字母，英文字符不变

* 例如：阿飞→af

*/

public static String getPinYinHeadChar(String chines) {

sb.setLength(0);

char[] chars = chines.toCharArray();

HanyuPinyinOutputFormat defaultFormat = new HanyuPinyinOutputFormat();

defaultFormat.setCaseType(HanyuPinyinCaseType.LOWERCASE);

defaultFormat.setToneType(HanyuPinyinToneType.WITHOUT_TONE);

for (int i = 0; i < chars.length; i++) {

if (chars[i] > 128) {

try {

sb.append(PinyinHelper.toHanyuPinyinStringArray(chars[i], defaultFormat)[0].charAt(0));

} catch (Exception e) {

e.printStackTrace();

}

} else {

sb.append(chars[i]);

}

}

return sb.toString();

}

/**

* 获取汉字字符串的第一个字母

*/

public static String getPinYinFirstLetter(String str) {

sb.setLength(0);

char c = str.charAt(0);

String[] pinyinArray = PinyinHelper.toHanyuPinyinStringArray(c);

if (pinyinArray != null) {

sb.append(pinyinArray[0].charAt(0));

} else {

sb.append(c);

}

return sb.toString();

}

/**

* 获取汉字字符串的汉语拼音，英文字符不变

*/

public static String getPinYin(String chines) {

sb.setLength(0);

char[] nameChar = chines.toCharArray();

HanyuPinyinOutputFormat defaultFormat = new HanyuPinyinOutputFormat();

defaultFormat.setCaseType(HanyuPinyinCaseType.LOWERCASE);

defaultFormat.setToneType(HanyuPinyinToneType.WITHOUT_TONE);

for (int i = 0; i < nameChar.length; i++) {

if (nameChar[i] > 128) {

try {

sb.append(PinyinHelper.toHanyuPinyinStringArray(nameChar[i], defaultFormat)[0]);

} catch (Exception e) {

e.printStackTrace();

}

} else {

sb.append(nameChar[i]);

}

}

return sb.toString();

}

}

　　一个排序的adapter，来展示好友列表

package com.example.newbsh.UI.friends.list;

import android.content.Context;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.TextView;

import android.widget.Toast;

import com.example.newbsh.R;

import java.util.List;

public class SortAdapter extends BaseAdapter {

private List list = null;

private Context mContext;

public SortAdapter(Context mContext, List list) {

this.mContext = mContext;

this.list = list;

}

public int getCount() {

return this.list.size();

}

public Object getItem(int position) {

return list.get(position);

}

public long getItemId(int position) {

return position;

}

public View getView(final int position, View view, ViewGroup arg2) {

ViewHolder viewHolder;

final User user = list.get(position);

if (view == null) {

viewHolder = new ViewHolder();

view = LayoutInflater.from(mContext).inflate(R.layout.friend_item, null);

viewHolder.name = (TextView) view.findViewById(R.id.name);

viewHolder.catalog = (TextView) view.findViewById(R.id.catalog);

view.setTag(viewHolder);

} else {

viewHolder = (ViewHolder) view.getTag();

}

//根据position获取首字母作为目录catalog

String catalog = list.get(position).getFirstLetter();

//如果当前位置等于该分类首字母的Char的位置 ，则认为是第一次出现

if(position == getPositionForSection(catalog)){

viewHolder.catalog.setVisibility(View.VISIBLE);

viewHolder.catalog.setText(user.getFirstLetter().toUpperCase());

}else{

viewHolder.catalog.setVisibility(View.GONE);

}

viewHolder.name.setText(this.list.get(position).getName());

return view;

}

final static class ViewHolder {

TextView catalog;

TextView name;

}

/**

* 获取catalog首次出现位置

*/

public int getPositionForSection(String catalog) {

for (int i = 0; i < getCount(); i++) {

String sortStr = list.get(i).getFirstLetter();

if (catalog.equalsIgnoreCase(sortStr)) {

return i;

}

}

return -1;

}

}

　　　FriendFragment的设置，装配好友信息（没有写添加好友，目前是静态数据）

package com.example.newbsh.UI.friends;

import androidx.lifecycle.ViewModelProviders;

import android.os.Bundle;

import androidx.annotation.NonNull;

import androidx.annotation.Nullable;

import androidx.fragment.app.Fragment;

import android.util.Log;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ListView;

import android.widget.TextView;

import com.example.newbsh.MainActivity;

import com.example.newbsh.R;

import com.example.newbsh.UI.friends.list.SideBar;

import com.example.newbsh.UI.friends.list.SortAdapter;

import com.example.newbsh.UI.friends.list.User;

import java.util.ArrayList;

import java.util.Collections;

public class FriendFragment extends Fragment {

private FriendViewModel mViewModel;

private View view;

private ListView listView;

private SideBar sideBar;

private ArrayList list;

private String getUsername(){

return MainActivity.getUserName();

}

public static FriendFragment newInstance() {

return new FriendFragment();

}

@Override

public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,

@Nullable Bundle savedInstanceState) {

view=inflater.inflate(R.layout.friend_fragment, container, false);

return view;

}

@Override

public void onActivityCreated(@Nullable Bundle savedInstanceState) {

super.onActivityCreated(savedInstanceState);

mViewModel = ViewModelProviders.of(this).get(FriendViewModel.class);

// TODO: Use the ViewModel

initView();

initData();

}

private void initView() {

listView = (ListView) view.findViewById(R.id.listView);

sideBar = (SideBar) view.findViewById(R.id.side_bar);

sideBar.setOnStrSelectCallBack(new SideBar.ISideBarSelectCallBack() {

@Override

public void onSelectStr(int index, String selectStr) {

for (int i = 0; i < list.size(); i++) {

if (selectStr.equalsIgnoreCase(list.get(i).getFirstLetter())) {

listView.setSelection(i); // 选择到首字母出现的位置

return;

}

}

}

});

}

private void initData() {

list = new ArrayList<>();

list.add(new User("亳州")); // 亳[bó]属于不常见的二级汉字

list.add(new User("大娃"));

list.add(new User("二娃"));

list.add(new User("三娃"));

list.add(new User("四娃"));

list.add(new User("五娃"));

list.add(new User("六娃"));

list.add(new User("七娃"));

list.add(new User("喜羊羊"));

list.add(new User("美羊羊"));

list.add(new User("懒羊羊"));

list.add(new User("沸羊羊"));

list.add(new User("暖羊羊"));

list.add(new User("慢羊羊"));

list.add(new User("灰太狼"));

list.add(new User("红太狼"));

list.add(new User("孙悟空"));

list.add(new User("黑猫警长"));

list.add(new User("舒克"));

list.add(new User("贝塔"));

list.add(new User("海尔"));

list.add(new User("阿凡提"));

list.add(new User("邋遢大王"));

list.add(new User("哪吒"));

list.add(new User("没头脑"));

list.add(new User("不高兴"));

list.add(new User("蓝皮鼠"));

list.add(new User("大脸猫"));

list.add(new User("大头儿子"));

list.add(new User("小头爸爸"));

list.add(new User("蓝猫"));

list.add(new User("淘气"));

list.add(new User("叶峰"));

list.add(new User("楚天歌"));

list.add(new User("江流儿"));

list.add(new User("Tom"));

list.add(new User("Jerry"));

list.add(new User("12345"));

list.add(new User("54321"));

list.add(new User("_(:з」∠)_"));

list.add(new User("……%￥#￥%#"));

Collections.sort(list); // 对list进行排序，需要让User实现Comparable接口重写compareTo方法

SortAdapter adapter = new SortAdapter(view.getContext(), list);

listView.setAdapter(adapter);

}

}

　　最终展示

 点击右侧会有大波浪来展示当前的字母排序的好友

精彩链接