Question

我已使用Runnable查找状态栏的高度，并提供正确的输出。

但如何在run()的{{1}}方法之外访问 StatusBarHeight ？

这是我的代码：

Runnable

P.S。：如果我在@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final RelativeLayout main = (RelativeLayout) findViewById(R.id.main); final Rect rectgle = new Rect(); final Window window = getWindow(); main.post(new Runnable() { @Override public void run() { window.getDecorView().getWindowVisibleDisplayFrame(rectgle); int StatusBarHeight = rectgle.top; int contentViewTop = window.findViewById( Window.ID_ANDROID_CONTENT).getTop(); int TitleBarHeight = contentViewTop - StatusBarHeight; Log.i("ScreenDemo", "StatusBar Height= " + StatusBarHeight + " , TitleBar Height = " + TitleBarHeight); } }); }中直接在run()内编写代码，则会返回 0 ，因为UI尚未呈现。
任何帮助表示赞赏。

Answer 1

你的变量StatusBarHeight的范围是块内的本地，如果你想从onCreate（）方法访问它，那么你需要按照以下方式声明它，

private static int StatusBarHeight;  // class level declaration

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

        final RelativeLayout main = (RelativeLayout) findViewById(R.id.main);

        final Rect rectgle = new Rect();
        final Window window = getWindow();

        main.post(new Runnable() {
            @Override
            public void run() {

                window.getDecorView().getWindowVisibleDisplayFrame(rectgle);
                StatusBarHeight = rectgle.top;
                int contentViewTop = window.findViewById(
                        Window.ID_ANDROID_CONTENT).getTop();
                int TitleBarHeight = contentViewTop - StatusBarHeight;

                Log.i("ScreenDemo", "StatusBar Height= " + StatusBarHeight
                        + " , TitleBar Height = " + TitleBarHeight);
            }
        });
}

Answer 2

您需要在类中将变量声明为私有成员变量，以便可以在Runnable之外访问它。像这样：

private int statusBarHeight; // member variable available to all methods in the class

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);    
    final RelativeLayout main = (RelativeLayout) findViewById(R.id.main);
    final Rect rectgle = new Rect();
    final Window window = getWindow();
    main.post(new Runnable() {
        @Override
        public void run() {
            window.getDecorView().getWindowVisibleDisplayFrame(rectgle);
            statusBarHeight = rectgle.top;
            int contentViewTop = window.findViewById(
                     Window.ID_ANDROID_CONTENT).getTop();
            int titleBarHeight = contentViewTop - statusBarHeight;
            Log.i("ScreenDemo", "StatusBar Height= " + statusBarHeight
                     + " , TitleBar Height = " + titleBarHeight);
        }
    });
}

注意：我已将变量名称从StatusBarHeight更改为statusBarHeight，从TitleBarHeight更改为titleBarHeight。请记住为变量使用初始小写名称。 Java命名约定使用初始小写变量名和类名的初始大写。

在分配方法之外访问私有变量

2 个答案: