Android 遍历界面所有的View-编程知识

Android 遍历界面所有的View

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一、导读

我们继续总结学习，温故知新。

二、概览

本文讲述如何遍历获取页面中所有的view，并输出对应的id，textview文本内容，imageview实际大小及设置的图片大小。

可用于检测android应用中的大图。

三、实践

不多说，直接上代码，

图片大小检测思路。

    fun checkBitmapFromView(){//1、遍历activity中的各个View控件//2、获取View控件加载的Bitmap//3、对比Bitmap宽高与View宽高}

示例代码:
遍历获取所有的view，并输出相应的信息

List<View> viewList=new ArrayList<>();@Overrideprotected void onResume() {super.onResume();logoIcon.postDelayed(new Runnable() {@Overridepublic void run() {getAllViews((ViewGroup) getWindow().getDecorView());for (View view: viewList) {if(view instanceof TextView) {Log.d("xyz", view.toString());Log.d("xyz", ((TextView)view).getText().toString());} else if(view instanceof ImageView) {Log.d("xyz", view.toString());checkBitmap(view, ((ImageView)view).getDrawable());} else {Log.d("xyz", view.toString());}}}}, 3000);}

//获取所有的子view，我们这里只保存imageview及textview，用于测试private List<View> getAllViews(ViewGroup viewGroup){for(int i=0;i< viewGroup.getChildCount(); i++){View view = viewGroup.getChildAt(i);if(view instanceof ViewGroup) {getAllViews((ViewGroup) view);} else {if(view instanceof ImageView || view instanceof TextView) {viewList.add(view);}if(view.getVisibility() == View.VISIBLE) {}}}return viewList;}

ImageView大小检测

private void checkBitmap(Object thiz, Drawable drawable) {if (drawable instanceof BitmapDrawable && thiz instanceof View) {final Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();final View view = (View) thiz;int width = view.getWidth();int height = view.getHeight();if (bitmap != null) {if (width > 0 && height > 0) {// 图标宽高都大于view带下的2倍以上，则警告if (bitmap.getWidth() >= (width << 1)&& bitmap.getHeight() >= (height << 1)) {
//                        warn(bitmap.getWidth(), bitmap.getHeight(), width, height, new RuntimeException("Bitmap size too large"));}warn(bitmap.getWidth(), bitmap.getHeight(), width, height, new RuntimeException("log"));} else {final Throwable stackTrace = new RuntimeException();view.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {@Overridepublic boolean onPreDraw() {int w = view.getWidth();int h = view.getHeight();if (w > 0 && h > 0) {if (bitmap.getWidth() >= (w << 1)&& bitmap.getHeight() >= (h << 1)) {
//                                    warn(bitmap.getWidth(), bitmap.getHeight(), w, h, stackTrace);}warn(bitmap.getWidth(), bitmap.getHeight(), w, h, stackTrace);view.getViewTreeObserver().removeOnPreDrawListener(this);}return true;}});}} else {warn(bitmap.getWidth(), bitmap.getHeight(), width, height, new RuntimeException("bitmap null"));}}}private void warn(int bitmapWidth, int bitmapHeight, int viewWidth, int viewHeight, Throwable t) {String warnInfo = new StringBuilder("Bitmap info: ").append("\n real size: (").append(bitmapWidth).append(',').append(bitmapHeight).append(')').append("\n desired size: (").append(viewWidth).append(',').append(viewHeight).append(')').append("\n call stack trace: \n").append(Log.getStackTraceString(t)).append('\n').toString();Log.d("xyz", warnInfo);}

我们看下log输出

com.xxx.xxx.xxx.ImageViewFor{e292c7e VFED..C.. ........ 540,1348-900,1528 #7f0a024e app:id/bt_phone}
2023-08-23 18:28:47.956 12556-12556 xyz                com.xxx.xxx                      D  Bitmap info: real size: (144,144)desired size: (360,180)call stack trace: java.lang.RuntimeException: logat com.xxx.xxx.ui.LoginActivity.checkBitmap(LoginActivity.java:235)at com.xxx.xxx.ui.LoginActivity.access$100(LoginActivity.java:79)at com.xxx.xxx.ui.LoginActivity$2.run(LoginActivity.java:193)at android.os.Handler.handleCallback(Handler.java:900)at android.os.Handler.dispatchMessage(Handler.java:103)at android.os.Looper.loop(Looper.java:219)at android.app.ActivityThread.main(ActivityThread.java:8673)at java.lang.reflect.Method.invoke(Native Method)at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1109)