获取工具栏的导航图标视图参考

Question

我想突出我的抽屉图标Toolbar(制作教程).为此,我需要它的立场.如何获得抽屉导航图标(汉堡包)视图的参考？

Answer 1

您可以使用视图的内容描述,然后使用findViewWithText()方法获取视图参考

 public static View getToolbarNavigationIcon(Toolbar toolbar){
        //check if contentDescription previously was set
        boolean hadContentDescription = !TextUtils.isEmpty(toolbar.getNavigationContentDescription());
        String contentDescription = hadContentDescription ? toolbar.getNavigationContentDescription() : "navigationIcon";
        toolbar.setNavigationContentDescription(contentDescription);
        ArrayList<View> potentialViews = new ArrayList<View>();
        //find the view based on it's content description, set programatically or with android:contentDescription
        toolbar.findViewsWithText(potentialViews,contentDescription, View.FIND_VIEWS_WITH_CONTENT_DESCRIPTION);
        //Nav icon is always instantiated at this point because calling setNavigationContentDescription ensures its existence 
        View navIcon = null;
        if(potentialViews.size() > 0){
            navIcon = potentialViews.get(0); //navigation icon is ImageButton
        }
         //Clear content description if not previously present
        if(!hadContentDescription)
            toolbar.setNavigationContentDescription(null);
        return navIcon;
     }

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Answer 2

在调试模式下查看工具栏的子视图后,我看到可以在那里找到抽屉图标,作为ImageButton.(感谢Elltz)

我使用带有2个子节点的自定义xml布局的工具栏(LinearLayout和ImageView),所以我的工具栏最后有4个孩子,这些位置:

[0] LinearLayout(from custom xml)
[1] ImageView(from custom xml)
[2] ImageButton(drawer icon)
[3] ActionMenuView(menu icon)

知道了这一点,我现在可以使用:

View drawerIcon = toolbar.getChildAt(2);

获取对抽屉菜单图标的引用.在我的例子中,位置是2.此位置应该等于自定义工具栏布局中的子视图的数量.

如果有人找到更好的解决方案,请告诉我.

Answer 3

如果您只想Drawable表示工具栏导航图标,则可以执行以下操作:

Drawable d = mToolbar.getNavigationIcon();

您可以通过如下方法获得对用于工具栏导航图标的ImageButton的引用:

public ImageButton getToolbarNavigationButton() {
    int size = mToolbar.getChildCount();
    for (int i = 0; i < size; i++) {
        View child = mToolbar.getChildAt(i);
        if (child instanceof ImageButton) {
            ImageButton btn = (ImageButton) child;
            if (btn.getDrawable() == mToolbar.getNavigationIcon()) {
                return btn;
            }
        }
    }
    return null;
}