Question

我找到了一种解决方法，可以在嵌套的PreferenceScreen上实际启用ActionBar主页按钮...但是它并没有在我的PreferenceActivity中调用OnOptionsItemSelected。有人知道在嵌套的PreferenceScreen上实际使用主页按钮的方法吗？

此处修改第35条：

http://code.google.com/p/android/issues/detail?id=4611

@Override
    public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference)
    {
        super.onPreferenceTreeClick(preferenceScreen, preference);
        if (preference!=null)
            if (preference instanceof PreferenceScreen)
                if (((PreferenceScreen)preference).getDialog()!=null)
                    ((PreferenceScreen)preference).getDialog().getActionBar().setHomeButtonEnabled(true);
        return false;
    }

Answer 1

我最近遇到了这个问题，这就是我解决它的方法。首先访问PreferenceScreen我使用与上面提到的完全相同的方法。

@Override
public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
    super.onPreferenceTreeClick(preferenceScreen, preference);

    // If the user has clicked on a preference screen, set up the action bar
    if (preference instanceof PreferenceScreen) {
        initializeActionBar((PreferenceScreen) preference);
    }

    return false;
}

从这里开始我研究了PreferenceScreen是什么，我很难过发现它只是一个Dialog的包装器。接下来，我设置操作栏显示选项并尝试找到主页按钮区域。遗憾的是，这并不容易获得，但在层次结构查看器的帮助下，我设法通过查找主页图标然后查看其父视图来获取访问权限。一旦我们有权访问包含的LinearLayout，我们就可以附加一个onClickListener来解除PreferenceScreen的对话框，该对话框调用PreferenceScreen's onDismissListener并将我们返回到上一个屏幕。

/** Sets up the action bar for an {@link PreferenceScreen} */
public static void initializeActionBar(PreferenceScreen preferenceScreen) {
    final Dialog dialog = preferenceScreen.getDialog();

    if (dialog != null) {
        // Inialize the action bar
        dialog.getActionBar().setDisplayHomeAsUpEnabled(true);

        // Apply custom home button area click listener to close the PreferenceScreen because PreferenceScreens are dialogs which swallow
        // events instead of passing to the activity
        // Related Issue: https://code.google.com/p/android/issues/detail?id=4611
        View homeBtn = dialog.findViewById(android.R.id.home);

        if (homeBtn != null) {
            OnClickListener dismissDialogClickListener = new OnClickListener() {
                @Override
                public void onClick(View v) {
                    dialog.dismiss();
                }
            };

            // Prepare yourselves for some hacky programming
            ViewParent homeBtnContainer = homeBtn.getParent();

            // The home button is an ImageView inside a FrameLayout
            if (homeBtnContainer instanceof FrameLayout) {
                ViewGroup containerParent = (ViewGroup) homeBtnContainer.getParent();

                if (containerParent instanceof LinearLayout) {
                    // This view also contains the title text, set the whole view as clickable
                    ((LinearLayout) containerParent).setOnClickListener(dismissDialogClickListener);
                } else {
                    // Just set it on the home button
                    ((FrameLayout) homeBtnContainer).setOnClickListener(dismissDialogClickListener);
                }
            } else {
                // The 'If all else fails' default case
                homeBtn.setOnClickListener(dismissDialogClickListener);
            }
        }    
    }
}

操作栏主页按钮无法使用嵌套的PreferenceScreen

1 个答案: