android - 如何在对话框中保持沉浸式模式？

Question

当我的 Activity 显示自定义对话框时，如何保持新的沉浸式模式？

我正在使用下面的代码来维护对话框中的沉浸式模式，但使用该解决方案时，当我启动自定义对话框时，导航栏出现不到一秒钟，然后消失。

以下视频更好地解释了该问题(在出现导航栏时查看屏幕底部):http://youtu.be/epnd5ghey8g

如何避免这种行为？

代码

我的应用程序中所有 Activity 的父亲:

public abstract class ImmersiveActivity extends Activity {

    @SuppressLint("NewApi")
    private void disableImmersiveMode() {
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
            getWindow().getDecorView().setSystemUiVisibility(
                    View.SYSTEM_UI_FLAG_FULLSCREEN
            );
        }
    }

    @SuppressLint("NewApi")
    private void enableImmersiveMode() {
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
            getWindow().getDecorView().setSystemUiVisibility(
                      View.SYSTEM_UI_FLAG_LAYOUT_STABLE 
                    | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION 
                    | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN 
                    | View.SYSTEM_UI_FLAG_FULLSCREEN 
                    | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY 
                    | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
            );
        }
    }


    /**
     * Set the Immersive mode or not according to its state in the settings:
     * enabled or not.
     */
    protected void updateSystemUiVisibility() {
        // Retrieve if the Immersive mode is enabled or not.
        boolean enabled = getSharedPreferences(Util.PREF_NAME, 0).getBoolean(
                "immersive_mode_enabled", true);

        if (enabled) enableImmersiveMode();
        else disableImmersiveMode();
    }

    @Override
    public void onResume() {
        super.onResume();
        updateSystemUiVisibility();
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        updateSystemUiVisibility();
    }

}

---

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我所有的自定义对话框都在其 onCreate(. . .) 方法中调用此方法:

/**
 * Copy the visibility of the Activity that has started the dialog {@link mActivity}. If the
 * activity is in Immersive mode the dialog will be in Immersive mode too and vice versa.
 */
@SuppressLint("NewApi")
private void copySystemUiVisibility() {
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
        getWindow().getDecorView().setSystemUiVisibility(
                mActivity.getWindow().getDecorView().getSystemUiVisibility()
        );
    }
}

---

---

编辑 - 解决方案(感谢 Beaver6813，查看他的答案了解更多详情):

我所有的自定义对话框都以这种方式覆盖 show 方法:

/**
 * An hack used to show the dialogs in Immersive Mode (that is with the NavBar hidden). To
 * obtain this, the method makes the dialog not focusable before showing it, change the UI
 * visibility of the window like the owner activity of the dialog and then (after showing it)
 * makes the dialog focusable again.
 */
@Override
public void show() {
    // Set the dialog to not focusable.
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
            WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE);

    copySystemUiVisibility();

    // Show the dialog with NavBar hidden.
    super.show();

    // Set the dialog to focusable again.
    getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE);
}

Answer 1

在对该问题进行大量研究后，有一个解决此问题的骇人听闻的方法，其中涉及拆开 Dialog类找到。将对话框窗口添加到窗口管理器时会显示导航栏，即使您在将其添加到管理器之前设置了 UI 可见性也是如此。在 Android Immersive example有人评论说:

// * Uses semi-transparent bars for the nav and status bars
// * This UI flag will *not* be cleared when the user interacts with the UI.
// When the user swipes, the bars will temporarily appear for a few seconds and then
// disappear again.

我相信这就是我们在这里看到的(当一个新的、可聚焦的窗口 View 添加到管理器时，会触发用户交互)。

我们如何解决这个问题？在我们创建 Dialog 时使其不可聚焦(因此我们不会触发用户交互)，然后在它显示后使其可聚焦。

//Here's the magic..
//Set the dialog to not focusable (makes navigation ignore us adding the window)
dialog.getWindow().setFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE, WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE);

//Show the dialog!
dialog.show();

//Set the dialog to immersive
dialog.getWindow().getDecorView().setSystemUiVisibility(
context.getWindow().getDecorView().getSystemUiVisibility());

//Clear the not focusable flag from the window
dialog.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE);

显然这并不理想，但它似乎是一个 Android 错误，他们应该检查 Window 是否具有沉浸式设置。

我已将我的工作测试代码更新为 Github .我已经在 Nexus 5 模拟器上进行了测试，它可能会因任何低于 KitKat 的东西而崩溃，但它仅用于概念验证。