Question

我正在使用ActionBarActivity并尝试使用以下命令获取主页按钮（汉堡）的位置：

View home = findViewById(android.support.v7.appcompat.R.id.home);

和/或

View home = findViewById(android.R.id.home);

问题是我总是得到null。有谁知道如何获得视图？也许我想从错误的地方拿到它

我试图从OnCreateOptionsMenu（菜单菜单）

获取它

Answer 1

这样做：

getActionBar().setHomeButtonEnabled(true);

View home = findViewById(android.R.id.home);

Answer 2

我遵循NikolasDespotoski代码，我现在能够得到它

Code here

谢谢你们

Answer 3

为避免代码在将来消失，我只是复制了@rendellhb提供的Gist

public class ToolbarNavigationUtil {
    public static View getToolbarNavigationIcon ( Toolbar toolbar ){
        //check if contentDescription previously was set 
        boolean hadContentDescription = TextUtils. isEmpty(toolbar.getNavigationContentDescription());
        String contentDescription = !hadContentDescription ? toolbar.getNavigationContentDescription().toString() : "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;
    }

    public static TextView getToolbarTitleView ( ActionBarActivity activity , Toolbar toolbar ){
        ActionBar actionBar = activity . getSupportActionBar();
        CharSequence actionbarTitle = null ;
        if (actionBar != null )
            actionbarTitle = actionBar . getTitle();
        actionbarTitle = TextUtils . isEmpty(actionbarTitle) ? toolbar . getTitle() : actionbarTitle;
        if ( TextUtils . isEmpty(actionbarTitle)) return null ;
        // can't find if title not set 
        for ( int i = 0 ; i < toolbar . getChildCount(); i ++ ){
            View v = toolbar . getChildAt(i);
            if (v != null && v instanceof TextView ){
                TextView t = (TextView) v;
                CharSequence title = t . getText();
                if ( ! TextUtils . isEmpty(title) && actionbarTitle . equals(title) && t . getId() == View . NO_ID ){
                    //Toolbar does not assign id to views with layout params SYSTEM, hence getId() == View.NO_ID 
                    //in same manner subtitle TextView can be obtained. 
                    return t;
                }
            }
        }
        return null ;
    }
}

Answer 4

这是我的解决方案，对我有用。

setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar_actionbar);
Log.d("checksize",toolbar.getChildCount()); \\print 1, this child is title
setSupportActionBar(toolbar);
Log.d("checksize",toolbar.getChildCount()); \\print 2
View navIcon = toolbar.toolbar.getChildAt(1);

Answer 5

这对我有用：

使用扩展“NoActionBar”的样式作为活动的主题
在活动的布局文件中创建一个工具栏

然后这样查询home键

使用 Kotlin： val image = toolbar.getChildAt(1) as AppCompatImageButton

使用 Java： AppCompatImageButton imageButton = (AppCompatImageButton)toolbar.getChildAt(1)

如何在appcompat.v7中获取主页视图

5 个答案: