Android如何获取系统高度、标题栏和状态栏高度

在android应用中，有时需要计算个View的位置，导致需要计算状态栏高度，标题栏高度等信息。为以后方便，在此做个简单记录。

晒代码前先了解一下android屏幕区域的划分，如下图（该图引用自此文http://www.iteye.com/topic/828830 ）

1、 屏幕区域的获取

activity.getWindowManager().getDefaultDisplay();

2、应用区域的获取

Rect outRect = new Rect();
activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(outRect);

其中，outRect.top 即是状态栏高度。

3、view绘制区域获取

Rect outRect = new Rect();
activity.getWindow().findViewById(Window.ID_ANDROID_CONTENT).getDrawingRect(outRect);

用绘制区域的outRect.top - 应用区域的outRect.top 即是标题栏的高度。

注意： 如果刚启动Activity时就要计算这些数据，最好在 onWindowFocusChanged  函数中进行， 否则得到的某些数据可能是错误的，比如，应用区域高宽的获取。

详细代码如下：

public class ScreenSize extends Activity {
    private TextView mScreenSizeView ;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_screen_size);
        mScreenSizeView = (TextView) findViewById(R.id.screen_size);
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        if(hasFocus){
            System.out.println("second");
            StringBuilder sb = new StringBuilder();
            Dimension dimen1 = getAreaOne(this);
            Dimension dimen2 = getAreaTwo(this);
            Dimension dimen3 = getAreaThree(this);
            sb.append("Area one : 
	Width: "+dimen1.mWidth + ";	Height: "+dimen1.mHeight);
            sb.append("
Area two: 
	Width: "+dimen2.mWidth + ";	Height: "+dimen2.mHeight);
            sb.append("
Area three: 
	Width: "+dimen3.mWidth + ";	Height: "+dimen3.mHeight);
            mScreenSizeView.setText(sb.toString());
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_screen_size, menu);
        return true;
    }

    private Dimension getAreaOne(Activity activity){
        Dimension dimen = new Dimension();
        Display disp = activity.getWindowManager().getDefaultDisplay();
        Point outP = new Point();
        disp.getSize(outP);
        dimen.mWidth = outP.x ;
        dimen.mHeight = outP.y;
        return dimen;
    }
    private Dimension getAreaTwo(Activity activity){
        Dimension dimen = new Dimension();
      Rect outRect = new Rect();
      activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(outRect);
      System.out.println("top:"+outRect.top +" ; left: "+outRect.left) ;
      dimen.mWidth = outRect.width() ;
      dimen.mHeight = outRect.height();
        return dimen;
    }
    private Dimension getAreaThree(Activity activity){
        Dimension dimen = new Dimension();
     // 用户绘制区域
        Rect outRect = new Rect();
        activity.getWindow().findViewById(Window.ID_ANDROID_CONTENT).getDrawingRect(outRect);
        dimen.mWidth = outRect.width() ;
        dimen.mHeight = outRect.height();
        // end
        return dimen;
    }

private class Dimension {
    public int mWidth ;
    public int mHeight ;
    public Dimension(){}
}