android获取屏幕宽高与获取控件宽高

获取屏幕宽高// 获取屏幕宽高（方法1）int screenWidth = getWindowManager().getDefaultDisplay().getWidth(); // 屏幕宽（像素，如：480px）int screenHeight = getWindowManager().getDefaultDisplay().getHeight(); // 屏幕高（像素，如：800p）Log.e(TAG + " getDefaultDisplay", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);// 获取屏幕密度（方法2）DisplayMetrics dm = new DisplayMetrics();dm = getResources().getDisplayMetrics();float density = dm.density; // 屏幕密度（像素比例：0.75/1.0/1.5/2.0）int densityDPI = dm.densityDpi; // 屏幕密度（每寸像素：120/160/240/320）float xdpi = dm.xdpi;float ydpi = dm.ydpi;Log.e(TAG + " DisplayMetrics", "xdpi=" + xdpi + "; ydpi=" + ydpi);Log.e(TAG + " DisplayMetrics", "density=" + density + "; densityDPI=" + densityDPI);screenWidth = dm.widthPixels; // 屏幕宽（像素，如：480px）screenHeight = dm.heightPixels; // 屏幕高（像素，如：800px）Log.e(TAG + " DisplayMetrics(111)", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);// 获取屏幕密度（方法3）dm = new DisplayMetrics();getWindowManager().getDefaultDisplay().getMetrics(dm);density = dm.density; // 屏幕密度（像素比例：0.75/1.0/1.5/2.0）densityDPI = dm.densityDpi; // 屏幕密度（每寸像素：120/160/240/320）xdpi = dm.xdpi;ydpi = dm.ydpi;Log.e(TAG + " DisplayMetrics", "xdpi=" + xdpi + "; ydpi=" + ydpi);Log.e(TAG + " DisplayMetrics", "density=" + density + "; densityDPI=" + densityDPI);int screenWidthDip = dm.widthPixels; // 屏幕宽（dip，如：320dip）int screenHeightDip = dm.heightPixels; // 屏幕宽（dip，如：533dip）Log.e(TAG + " DisplayMetrics(222)", "screenWidthDip=" + screenWidthDip + "; screenHeightDip=" + screenHeightDip);screenWidth = (int)(dm.widthPixels * density + 0.5f); // 屏幕宽（px，如：480px）screenHeight = (int)(dm.heightPixels * density + 0.5f); // 屏幕高（px，如：800px）Log.e(TAG + " DisplayMetrics(222)", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);

获取控件的宽高，，一般来说，我们在onCreate里面得到的控件的宽高全是０.采用下面的方法，可以得到真实的宽高

//————————————————方法一int w = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED);int h = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED);imageView.measure(w, h);int height =imageView.getMeasuredHeight();int width =imageView.getMeasuredWidth();textView.append("\n"+height+","+width);　　　　此方法会加载onMeasure三次//———————————————–方法二ViewTreeObserver vto = imageView.getViewTreeObserver();vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {public boolean onPreDraw() {int height = imageView.getMeasuredHeight();int width = imageView.getMeasuredWidth();textView.append("\n"+height+","+width);return true;}});　　　　此方法会加载onMeasure二次，但是回调函数会回调很多次　　　　 //———————————————–方法三ViewTreeObserver vto2 = imageView.getViewTreeObserver();vto2.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {@Overridepublic void onGlobalLayout() {imageView.getViewTreeObserver().removeGlobalOnLayoutListener(this);textView.append("\n\n"+imageView.getHeight()+","+imageView.getWidth());}});　　　　　　　此方法会加载onMeasure二次，但是回调函数只回调一次

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