项目里面需要实现,点击webView里面的图片,看大图并且能够放大缩小效果,在此记录下实现过程。
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在webViewDelegate里面添加如下代码:
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- (void)webViewDidFinishLoad:(UIWebView *)aWebView { //调整字号 NSString *str = @"document.getElementsByTagName('body')[0].style.webkitTextSizeAdjust= '95%'"; [webView stringByEvaluatingJavaScriptFromString:str]; //js方法遍历图片添加点击事件 返回图片个数 static NSString * const jsGetImages = @"function getImages(){/ var objs = document.getElementsByTagName(/"img/");/ for(var i=0;i<objs.length;i++){/ objs[i].onclick=function(){/ document.location=/"myweb:imageClick:/"+this.src;/ };/ };/ return objs.length;/ };"; [webView stringByEvaluatingJavaScriptFromString:jsGetImages];//注入js方法 //注入自定义的js方法后别忘了调用 否则不会生效(不调用也一样生效了,,,不明白) NSString *resurlt = [webView stringByEvaluatingJavaScriptFromString:@"getImages()"]; //调用js方法 // NSLog(@"---调用js方法--%@ %s jsMehtods_result = %@",self.class,__func__,resurlt); }
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- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{ //将url转换为string NSString *requestString = [[request URL] absoluteString]; // NSLog(@"requestString is %@",requestString); //hasPrefix 判断创建的字符串内容是否以pic:字符开始 if ([requestString hasPrefix:@"myweb:imageClick:"]) { NSString *imageUrl = [requestString substringFromIndex:@"myweb:imageClick:".length]; // NSLog(@"image url------%@", imageUrl); if (bgView) { //设置不隐藏,还原放大缩小,显示图片 bgView.hidden = NO; imgView.frame = CGRectMake(10, 10, SCREEN_WIDTH-40, 220); [imgView setImageWithURL:[NSURL URLWithString:imageUrl] placeholderImage:LOAD_IMAGE(@"house_moren")]; } else [self showBigImage:imageUrl];//创建视图并显示图片 return NO; } return YES; }
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创建放大图片的视图
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#pragma mark 显示大图片 -(void)showBigImage:(NSString *)imageUrl{ //创建灰色透明背景,使其背后内容不可操作 bgView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT)]; [bgView setBackgroundColor:[UIColor colorWithRed:0.3 green:0.3 blue:0.3 alpha:0.7]]; [self.view addSubview:bgView]; //创建边框视图 UIView *borderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH-20, 240)]; //将图层的边框设置为圆脚 borderView.layer.cornerRadius = 8; borderView.layer.masksToBounds = YES; //给图层添加一个有色边框 borderView.layer.borderWidth = 8; borderView.layer.borderColor = [[UIColor colorWithRed:0.9 green:0.9 blue:0.9 alpha:0.7] CGColor]; [borderView setCenter:bgView.center]; [bgView addSubview:borderView]; //创建关闭按钮 UIButton *closeBtn = [UIButton buttonWithType:UIButtonTypeCustom]; // [closeBtn setImage:[UIImage imageNamed:@"close.png"] forState:UIControlStateNormal]; closeBtn.backgroundColor = [UIColor redColor]; [closeBtn addTarget:self action:@selector(removeBigImage) forControlEvents:UIControlEventTouchUpInside]; [closeBtn setFrame:CGRectMake(borderView.frame.origin.x+borderView.frame.size.width-20, borderView.frame.origin.y-6, 26, 27)]; [bgView addSubview:closeBtn]; //创建显示图像视图 imgView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, CGRectGetWidth(borderView.frame)-20, CGRectGetHeight(borderView.frame)-20)]; imgView.userInteractionEnabled = YES; [imgView setImageWithURL:[NSURL URLWithString:imageUrl] placeholderImage:LOAD_IMAGE(@"house_moren")]; [borderView addSubview:imgView]; //添加捏合手势 [imgView addGestureRecognizer:[[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(handlePinch:)]]; }
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实现关闭和捏合手势的方法
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//关闭按钮 -(void)removeBigImage { bgView.hidden = YES; } - (void) handlePinch:(UIPinchGestureRecognizer*) recognizer { //缩放:设置缩放比例 recognizer.view.transform = CGAffineTransformScale(recognizer.view.transform, recognizer.scale, recognizer.scale); recognizer.scale = 1; }
效果图如下
原创文章,作者:Maggie-Hunter,如若转载,请注明出处:https://blog.ytso.com/tech/aiops/3283.html