android中獲取屏幕的長於寬,參考了網上有很多代碼,但結果與實際不符,如我的手機是i9000,屏幕大小是480*800px,得到的結果卻爲320*533
結果很不靠譜,於是自己寫了幾行代碼,親測一下
測試參數:
測試環境: i9000(三星)
物理屏幕:480*800px
density :1.5
測試代碼:
- // 獲取屏幕密度(方法1)
- int screenWidth = getWindowManager().getDefaultDisplay().getWidth(); // 屏幕寬(像素,如:480px)
- int screenHeight = getWindowManager().getDefaultDisplay().getHeight(); // 屏幕高(像素,如:800p)
- Log.e(TAG + " getDefaultDisplay", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);
- // 獲取屏幕密度(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; // 屏幕寬(像素,如:480px)
- screenHeight = dm.heightPixels; // 屏幕高(像素,如:800px)
- Log.e(TAG + " DisplayMetrics(111)", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);
- // 獲取屏幕密度(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; // 屏幕寬(dip,如:320dip)
- int screenHeightDip = dm.heightPixels; // 屏幕寬(dip,如:533dip)
- Log.e(TAG + " DisplayMetrics(222)", "screenWidthDip=" + screenWidthDip + "; screenHeightDip=" + screenHeightDip);
- screenWidth = (int)(dm.widthPixels * density + 0.5f); // 屏幕寬(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);
結果如下:
- E/== MyScreenActivity =================================== getDefaultDisplay( 8509): screenWidth=320; screenHeight=533
- E/== MyScreenActivity =================================== DisplayMetrics( 8509): xdpi=156.3077; ydpi=157.51938
- E/== MyScreenActivity =================================== DisplayMetrics( 8509): density=1.0; densityDPI=160
- E/== MyScreenActivity =================================== DisplayMetrics(111)( 8509): screenWidth=320; screenHeight=533
- E/== MyScreenActivity =================================== DisplayMetrics( 8509): xdpi=234.46153; ydpi=236.27907
- E/== MyScreenActivity =================================== DisplayMetrics( 8509): density=1.5; densityDPI=240
- E/== MyScreenActivity =================================== DisplayMetrics(222)( 8509): screenWidthDip=320; screenHeightDip=533
- E/== MyScreenActivity =================================== DisplayMetrics(222)( 8509): screenWidth=480; screenHeight=800
在onDraw()方法中
方法1和2,得到的結果都一致,均爲320*533,明顯不是測試機i9000的屏幕大小
方法3,將方法1和2得到的結果,乘以density後,完美的480*800,perfect!
注: density 大於1的情況下,需要設置targetSdkVersion在4-9之間,例如
<uses-sdk android:minSdkVersion="3" android:targetSdkVersion="10" />
仔細分析代碼,發現問題出在代碼:
getWindowManager().getDefaultDisplay().getMetrics(dm)
Initialize a DisplayMetrics object from this display's data.
dm = getResources().getDisplayMetrics()
Return the current display metrics that are in effect for this resource object. The returned object should be treated as read-only.