html WKWebView OC IOS 设置UIViewController为背景半透明浮层弹窗，查看富文本图片详情

使用场景：UIViewController1 打开 UIViewController2（背景半透明弹窗）

案例：打开富文本网页图片的url查看图片详情

WKWebView  WKNavigationDelegate代理方法设置js代码点击事件 

///注册添加图片标签点击js方法

- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation{

///js添加图片点击事件

NSString *jsClickImage =@"function registerImageClickAction(){var imgs=document.getElementsByTagName('img');var length=imgs.length;for(var i=0; i < length;i++){img=imgs[i];if(\"ad\" ==img.getAttribute(\"flag\")){var parent = this.parentNode;if(parent.nodeName.toLowerCase() != \"a\")return;}img.onclick=function(){window.location.href='image-preview:'+this.src}}}";

[webView evaluateJavaScript:jsClickImage completionHandler:nil];

[webView evaluateJavaScript:@"registerImageClickAction()" completionHandler:nil];

[webView evaluateJavaScript:@"document.body.scrollHeight" completionHandler:^(id _Nullable result,NSError *_Nullable error) {

//获取webView内容高度

CGFloat height = [result doubleValue];

// [webView mas_updateConstraints:^(MASConstraintMaker *make) {

// make.height.equalTo(@(height));

// }];

webView.frame = CGRectMake(0, 0, self.frame.size.width, height);

[webView layoutIfNeeded];

[webView setNeedsLayout];

if (self.contentHeightCallback != nil) {

self.contentHeightCallback(CGSizeMake(self.frame.size.width, height));

}

}];

}

///拦截点击图片

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler{

NSString *requestString = navigationAction.request.URL.absoluteString;

NSString *imgKey = @"image-preview";

if([requestString hasPrefix: imgKey]){

NSString *url = [requestString substringFromIndex:imgKey.length+1];

//查看图片详情

[self showPicDetail:url];

decisionHandler(WKNavigationActionPolicyCancel);

return;

}

decisionHandler(WKNavigationActionPolicyAllow);

}

showPicDetail:()  方法打开浮窗：

-(void) showPicDetail:(NSString *)imgUrl{

ShowBigPicDetailViewController *vc = [[ShowBigPicDetailViewController alloc] init];

vc.imageUrl = imageUrl;

//设置全屏显示 关键语句，必须有

vc.modalPresentationStyle = UIModalPresentationOverCurrentContext;

[self presentViewController:vc animated:YES completion:nil];

}

设置UIViewController2 背景半透明

- (void)viewDidLoad {

[super viewDidLoad];

//设置半透明背景

[self.view setBackgroundColor:[UIColor colorWithRed:0 green:0 blue:0 alpha:0.5f]];

...

}

关闭浮窗弹窗：

[self dismissViewControllerAnimated:YES completion:nil];

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