获取工具栏的导航图标视图参考

Question

我想突出显示Toolbar中的抽屉图标（处理教程）。为此，我需要它的立场。如何获得抽屉式导航图标（汉堡包）视图的参考？

Answer 1

如果您只想获得代表工具栏导航图标的Drawable，您可以这样做：

Drawable d = mToolbar.getNavigationIcon();

您可以通过以下方法获取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;
}

Answer 2

即兴的@Nikola Despotoski's答案

public static View getNavigationIconView(Toolbar toolbar) { 

    String previousContentDescription = (String) toolbar.getNavigationContentDescription();
    // Check if contentDescription previously was set
    boolean hadContentDescription = !TextUtils.isEmpty(previousContentDescription);
    String contentDescription = hadContentDescription ? 
            previousContentDescription : "navigationIcon";
    toolbar.setNavigationContentDescription(contentDescription);

    ArrayList<View> potentialViews = new ArrayList<>();
    // Find the view based on it's content description, set programmatically 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(previousContentDescription);

    return navIcon;
}