列表活动崩溃与单击单选按钮菜单

Question

我正在尝试将"设置"菜单项添加到我的溢出菜单中。"设置"菜单具有单选按钮。问题是当我单击"设置"菜单项时，活动崩溃。

我的代码有什么问题？

谢谢你的帮助。

爪哇代码：

public class AudioPlayer extends ListActivity

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_action, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
setContentView(R.layout.audio_player_settings);
makeText(this, "Settings Menu Item Clicked", LENGTH_SHORT).show();
return true;
}
return super.onOptionsItemSelected(item);
}

menu_action.xml

<menu 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" tools:context=".PlayerActivity">
<item android:id="@+id/action_popup" android:title="Sort Popup" android:icon="@drawable/ic_sort"
android:showAsAction="always" />
<item android:id="@+id/action_settings" android:title="Settings"
app:showAsAction="never" />
<item android:id="@+id/action_help" android:title="Help"
app:showAsAction="never" />

audio_player_settings.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".PlayerActivity">
<RadioGroup xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/radio_group"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<RadioButton android:id="@+id/high_quality"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="High"
android:onClick="onRadioButtonClicked"/>
<RadioButton android:id="@+id/medium_quality"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Medium"
android:onClick="onRadioButtonClicked"/>
<RadioButton android:id="@+id/low_quality"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Low"
android:onClick="onRadioButtonClicked"/>
</RadioGroup>
</RelativeLayout>

日志猫：

03-08 12:22:10.300  31930-31930/com.test.audio E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.test.audio, PID: 31930
java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
at android.app.ListActivity.onContentChanged(ListActivity.java:243)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:382)
at android.app.Activity.setContentView(Activity.java:2145)
at com.test.audio.TouchActivity.onOptionsItemSelected(TouchActivity.java:2833)
at android.app.Activity.onMenuItemSelected(Activity.java:2885)
at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(PhoneWindow.java:1133)
at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:761)
at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:152)
at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:904)
at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:894)
at com.android.internal.view.menu.MenuPopupHelper.onItemClick(MenuPopupHelper.java:186)
at android.widget.AdapterView.performItemClick(AdapterView.java:305)
at android.widget.AbsListView.performItemClick(AbsListView.java:1146)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3053)
at android.widget.AbsListView$3.run(AbsListView.java:3860)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Answer 1

在onOptionsItemSelected中，您正在调用setContentView()它将活动的布局设置为要用作菜单布局的布局。

该布局不包含任何列表视图，因此这就是您收到错误的原因。

我认为您想打开一个新的活动或片段，而不是更改当前的布局。

活动示例：

在onOptionsItemSelected内，如果：

...
if (id == R.id.action_settings) {
makeText(this, "Settings Menu Item Clicked", LENGTH_SHORT).show();
Intent intent = new Intent(this, AudioPlayerSettings.class);
startActivity(intent);
return true;
}
...

然后使用如下所示的假装布局创建一个 AudioPlayerSettings 类：

public class AudioPlayerSettings extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.audio_player_settings);
}
}