Android标题栏最右边添加按钮

step1:重写activity的onCreateOptionsMenu方法

@Override
public boolean onCreateOptionsMenu(Menu menu){
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main, menu);
    return true;
}

step2: main.xml文件布局

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
   <item
        android:id="@+id/action_cart"
        android:title="扫描"
        android:orderInCategory="100"
        android:showAsAction="always"/>
</menu>

step3:如果监听按钮重写onOptionsItemSelected方法

@Override
public boolean onOptionsItemSelected(MenuItem item){
    switch (item.getItemId()) {
    case R.id.action_cart://监听菜单按钮    break;
    }
    return super.onOptionsItemSelected(item);
}  

效果图如下: