如何在Android DrawerLayout的左上角添加3行图标

Question

我drawerLayout编写新应用程序，我想将drawerLayout图标外观更改为典型的 3 条水平线。 如果我点击它，图标应该将他的外观更改为箭头。 现在我一直都有一个箭头图标。

包 pl.nieruchalski.scrumfamily;

import android.app.Activity;
import android.content.res.Configuration;
import android.os.PersistableBundle;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;

public class MainActivity extends Activity {

    private ActionBarDrawerToggle drawerToggle;
    private DrawerLayout drawerLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        drawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
        drawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.string.openDrawer, R.string.closeDrawer);
        drawerLayout.addDrawerListener(drawerToggle);
        getActionBar().setDisplayHomeAsUpEnabled(true);
        getActionBar().setHomeButtonEnabled(true);
    }

    @Override
    public void onPostCreate(Bundle savedInstanceState, PersistableBundle persistentState) {
        super.onPostCreate(savedInstanceState, persistentState);
        drawerToggle.syncState();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        drawerToggle.onConfigurationChanged(newConfig);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if(drawerToggle.onOptionsItemSelected(item))
            return true;
        return super.onOptionsItemSelected(item);
    }
}

Answer 1

你覆盖了错误的onPostCreate()方法，所以drawerToggle.syncState(); 永远不会被调用，并且切换永远不会在ActionBar上放置自己的图标。

您只需要使用Bundle参数覆盖onPostCreate()方法； 没有PersistableBundle参数。

@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    drawerToggle.syncState();
}

Answer 2

在onCreate()试试这个：

 getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setDefaultDisplayHomeAsUpEnabled(false);
    drawerToggle.setDrawerIndicatorEnabled(false);
    drawerToggle.setHomeAsUpIndicator(R.drawable.ic_custom_drawer_icon); //set your horizontal line icon
    drawerToggle.setToolbarNavigationClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            DrawerLayout drawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
            if (drawerLayout.isDrawerOpen(GravityCompat.START)) {
                drawerLayout.closeDrawer(GravityCompat.START); 
                drawerToggle.setHomeAsUpIndicator(R.drawable.ic_custom_drawer_icon); // drawer closed-reset icon
            } else {
                //open drawer
                drawerLayout.openDrawer(GravityCompat.START);
                drawerToggle.setHomeAsUpIndicator(R.drawable.ic_new_icon); // set your back icon
            }
        }
    });