上一篇博文里给自己挖了一个坑，今天把这个坑埋了。之前说listView的高度=屏幕高度-标题栏和状态栏高度-titleBar高度-bottomTab高度，titleBar和bottomTab都是自己画的View，这个不难理解，那么标题栏和状态栏是哪一块呢？见下图：

标题栏和状态栏是android默认给出的两栏，每个应用新建的时候都会出现，如果要去掉这两栏，可以在Activity的setContentView之前写两行代码：

this.requestWindowFeature(Window.FEATURE_NO_TITLE);//去掉标题栏
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,  
WindowManager.LayoutParams.FLAG_FULLSCREEN);//去掉状态栏 

如果不去掉这两栏，而是要获取两栏的高度，以此来更好的进行屏幕的适配，一般网上给出的下述的方法：

public class MainActivity extends Activity {
	private int topHeight;
	private int titleHeight;
	private int statusHeight;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		getHeight();
	}

	private void getHeight() {
		// 状态栏+标题栏总高度
		topHeight = getWindow().findViewById(Window.ID_ANDROID_CONTENT).getTop();
		// 状态栏高度
		Rect frame = new Rect();
		getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
		statusHeight = frame.top;
		//标题栏高度
		titleHeight = topHeight-statusHeight;
		Log.i("info", "topHeight>"+topHeight+" statusHeight>"+" titleHeight>"+titleHeight);
	}

}

很明显，这种方法无法得到两栏的高度（上一篇中并非通过该方法得到两栏高度，后来修改时忘记改代码了）。那么我们该如何来获取高度呢？有好几种方法：

方法一：在Activity中复写onWindowFocusChanged()方法，将上述的几行代码写在onWindowFocusChanged()方法中：

@Override
	public void onWindowFocusChanged(boolean hasFocus) {
		// TODO Auto-generated method stub
		super.onWindowFocusChanged(hasFocus);
		// 状态栏+标题栏总高度
		topHeight = getWindow().findViewById(Window.ID_ANDROID_CONTENT).getTop();
		// 状态栏高度
		Rect frame = new Rect();
		getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
		statusHeight = frame.top;
		// 标题栏高度
		titleHeight = topHeight - statusHeight;
		Log.i("info", "topHeight>" + topHeight + " statusHeight>" + statusHeight + " titleHeight>" + titleHeight);
	}

private void setListViewHeight() {
		// 测量屏幕高度
		DisplayMetrics metric = new DisplayMetrics();
		getWindowManager().getDefaultDisplay().getMetrics(metric);
		totalHeight = metric.heightPixels;
		Log.i("info", "totalHeight>"+totalHeight);
		//底部高度
		bottomHeight = bottomTab.getLayoutParams().height;
		Log.i("info", "bottomHeight>"+bottomHeight);
		//顶部高度
		Log.i("info", "titleHeightWithoutMeasure>"+titleBar.getMeasuredHeight());
		titleBar.measure(0, 0);
		titleHeight = titleBar.getMeasuredHeight();
		Log.i("info", "titleHeightWithMeasure>"+titleHeight);
		//设置listview高度
		list.getLayoutParams().height = totalHeight-contentViewTop-titleHeight-bottomHeight;
		Log.i("info", "listHeight>"+list.getLayoutParams().height );
	}
@Override
	public void onWindowFocusChanged(boolean hasFocus) {
		// TODO Auto-generated method stub
		super.onWindowFocusChanged(hasFocus);
		//状态栏高度
		Rect frame = new Rect();  
		getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);  
       		statusBarHeight = frame.top;  
       		// 获取标题栏+状态栏总高度
        	contentViewTop = getWindow()  
                .findViewById(Window.ID_ANDROID_CONTENT).getTop();  
        	// 标题栏高度  
       		titleBarHeight = contentViewTop - statusBarHeight;  
        	setListViewHeight();
		ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
				android.R.layout.simple_list_item_1, data);
		list.setAdapter(adapter);
	}

// 状态栏高度
int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
if (resourceId > 0) {
statusHeight = getResources().getDimensionPixelSize(resourceId);
}
Log.i("info", "statusHeight>" + statusHeight);

通过获取状态栏id的方式获取到状态栏的高度，很有意思的方法，有兴趣的同学可以去看看getIdentifier()和getDimensionPixelSize()这两个方法的源码

方法三也很有意思，我自己并没有去测试过。众所周知，Android的所有资源都会有惟一标识在R类中作为引用。我们也可以通过反射获取R类的实例域，代码如下：

public static int getStatusHeight(Context context) {
 //获取状态栏高度
    int statusHeight = -1;
    try {
        Class<!--?--> clazz = Class.forName("com.android.internal.R$dimen");
        Object object = clazz.newInstance();
        int height = Integer.parseInt(clazz.getField("status_bar_height")
                .get(object).toString());
        statusHeight = context.getResources().getDimensionPixelSize(height);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return statusHeight;
}