Android编程获取屏幕宽高与获取控件宽高的方法
作者:chenguang79
这篇文章主要介绍了Android编程获取屏幕宽高与获取控件宽高的方法,实例分析了Android针对屏幕及控件常用属性的相关操作技巧,需要的朋友可以参考下
本文实例讲述了Android编程获取屏幕宽高与获取控件宽高的方法。分享给大家供大家参考,具体如下:
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() { @Override public 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
希望本文所述对大家Android程序设计有所帮助。