点击应用图标打开导航抽屉

Question

我希望用户能通过点击应用图标来打开导航抽屉。这是我的代码：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_add);
    // Show the Up button in the action bar.

    DrawerLayout mDrawerLayout = (DrawerLayout) findViewById(R.id.left_drawer);
    ActionBarDrawerToggle mDrawerToggle = new ActionBarDrawerToggle(
            this,                  /* host Activity */
            mDrawerLayout, /* DrawerLayout object */
           R.drawable.ic_drawer,  /* nav drawer icon to replace 'Up' caret */
            R.string.drawer_open,  /* "open drawer" description */
            R.string.drawer_close  /* "close drawer" description */
            ) {

        /** Called when a drawer has settled in a completely closed state. */
        public void onDrawerClosed(View view) {
            getActionBar().setTitle(R.string.title_activity_add);
        }

        /** Called when a drawer has settled in a completely open state. */
        public void onDrawerOpened(View drawerView) {
            getActionBar().setTitle(R.string.drawer_title);
        }
    };


    mDrawerLayout.setDrawerListener(mDrawerToggle);
    getActionBar().setDisplayHomeAsUpEnabled(true); // Pressing the app icon in the action bar will navigate to the parent activity.
    getActionBar().setHomeButtonEnabled(true);

}

但是当我点击这个图标时，什么都没有发生。问题出在哪里呢？

- user2971688

Answer 1

请查看此处的文档示例。您需要在onPostCreate()中添加额外的代码来同步您的抽屉状态。

• onOptionsItemSelected()用于处理应用图标的触摸事件

• onConfigurationChanged()提供给抽屉新的配置

public class YourActivity extends Activity {

public ActionBarDrawerToggle mDrawerToggle;

@Override
protected void onCreate(Bundle savedInstanceState) {
    ...
    mDrawerToggle = new ActionBarDrawerToggle();
    ...
}

@Override
protected void onPostCreate(Bundle savedInstanceState) {
     super.onPostCreate(savedInstanceState);
     // Sync the toggle state after onRestoreInstanceState has occurred.
     mDrawerToggle.syncState();
}

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

@Override
public boolean onOptionsItemSelected(MenuItem item) {
     // Pass the event to ActionBarDrawerToggle, if it returns
     // true, then it has handled the app icon touch event
     if (mDrawerToggle.onOptionsItemSelected(item)) {
         return true;
     }
     // Handle your other action bar items...

     return super.onOptionsItemSelected(item);
}

}

- Steve Benett

---

谢谢。当我添加这段代码时，它显示mDrawerToogle无法解析。我尝试将其更改为"public ActionBarDrawerToggle mDrawerToggle = new ActionBarDrawerToggle"，但没有帮助。我在Java方面经验不是很丰富。 - user2971688

@user2971688 在您的Activity中将ActionBarDrawerToggle设置为一个字段，并相应地更改onCreate中的代码部分。 - Steve Benett

我添加了你的onPostCreate()、onConfigurationChanged和onOptionsItemSelected，但它显示“mDrawerToggle无法解析”？ - user2971688

仔细查看onCreate和上面的那行代码。 - Steve Benett

如上所述，ActionBarDrawerToogle没有构造函数。正确的构造函数是： mDrawerToggle = new ActionBarDrawerToggle(activity, drawerLayout, drawerImageRes, openDrawerContentDescRes, closeDrawerContentDescRes)。 - Mayur Shah

Answer 2

您应该重写活动的 onOptionsItemSelected 方法，并使用以下内容：

@Override
    public boolean onOptionsItemSelected(MenuItem item) {

        if (mDrawerToggle.onOptionsItemSelected(item)) {
            return true;
        }
        return super.onOptionsItemSelected(item);
}

- moallemi