java – 如何在android中的Action栏中创建按钮

我在Android应用程序上工作,我需要一个操作栏中的按钮.
这些是我的活动和java文件.
所以,我需要一个工具栏右侧的按钮.
提前致谢.

content_b2_bdeliveries.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.ideabiz.riderapplication.ui.B2BDeliveriesActivity"
tools:showIn="@layout/activity_b2_bdeliveries">
//remaining code;
</LinearLayout>

activity_b2_bdeliveries.xml：

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.ideabiz.riderapplication.ui.B2BDeliveriesActivity">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

</android.support.design.widget.AppBarLayout>

<include layout="@layout/content_b2_bdeliveries" />

</android.support.design.widget.CoordinatorLayout>

B2BDeliveriesActivity.java：

public class B2BDeliveriesActivity extends AppCompatActivity {
private final String TAG_NAME="B2BActivity";
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_b2_bdeliveries);
    sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
    ActionBar actionBar = getSupportActionBar();
    //Log.d(TAG_NAME,actionBar.toString());
    if (actionBar != null) {
        try {
            actionBar.setdisplayHomeAsUpEnabled(true);
            } catch (Exception e) {
                Crashlytics.logException(e);
                Log.d(TAG_NAME, "Null Pointer from setdisplayHomeAsUpEnabled" + e.getMessage());
                Utilities.issuetokenUpload("Null Pointer from setdisplayHomeAsUpEnabled" + e, sharedPreferences.getInt("tripId", 999999), sharedPreferences.getString("driverPhoneNo", "9999999999"), sharedPreferences.getString("driverName", "default"), getResources().getString(R.string.version));
            }
    }
}

解决方法:

// create an action bar button
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.mymenu, menu);
    return super.onCreateOptionsMenu(menu);
}

// handle button activities
@Override
public boolean onoptionsItemSelected(MenuItem item) {
    int id = item.getItemId();

    if (id == R.id.mybutton) {
    // do something here
    }
    return super.onoptionsItemSelected(item);
}

你的mymenu.xml应该在res / menu目录下(如果你没有res / menu,只需在res里面创建一个名为“menu”的目录),如下所示：

<menu xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto">
<item
    android:id="@+id/mybutton"
    android:title=""
    app:showAsAction="always"
    android:icon="@drawable/mybuttonicon"
    />
</menu>