我正在尝试运行遍历菜单及其工作方式的示例程序之一。但是每当我尝试编译和运行该示例时，我都会在标题中看到错误，并且无法查看任何菜单选项是否正常工作。
可能是这么简单，但在这一点上我感到疲倦和沮丧:(
package com.example.context_menu_demo;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.Color;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.Button;
import android.widget.RelativeLayout;
public class MainActivity extends Activity {
Button m_button;
RelativeLayout ourlayout;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ourlayout = (RelativeLayout) findViewById(R.id.layout_id);
m_button = (Button) findViewById(R.id.menu_but);
registerForContextMenu(m_button);
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
// TODO Auto-generated method stub
super.onCreateContextMenu(menu, v, menuInfo);
getMenuInflater().inflate(R.menu.menu, menu);
menu.setHeaderTitle("Context Menu");
}
@Override
public boolean onContextItemSelected(MenuItem item) {
// TODO Auto-generated method stub
switch (item.getItemId()) {
case R.id.red:
ourlayout.setBackgroundColor(Color.RED);
break;
case R.id.green:
ourlayout.setBackgroundColor(Color.GREEN);
break;
case R.id.blue:
ourlayout.setBackgroundColor(Color.BLUE);
break;
case R.id.gray:
ourlayout.setBackgroundColor(Color.GRAY);
break;
case R.id.cyan:
ourlayout.setBackgroundColor(Color.CYAN);
break;
case R.id.yellow:
ourlayout.setBackgroundColor(Color.YELLOW);
break;
}
return super.onOptionsItemSelected(item);
}
}
xmls
<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:id="@+id/layout_id">
<Button
android:id="@+id/menu_but"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="94dp"
android:text="Menu" />
<item android:id="@+id/red" android:title="RED"></item>
<item android:id="@+id/green" android:title="GREEN"></item>
<item android:id="@+id/blue" android:title="BLUE"></item>
<item android:id="@+id/gray" android:title="GRAY"></item>
<item android:id="@+id/cyan" android:title="CYAN"></item>
<item android:id="@+id/yellow" android:title="YELLOW"></item>
</RelativeLayout>
xmls
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@+id/red" android:title="RED"></item>
<item android:id="@+id/green" android:title="GREEN"></item>
<item android:id="@+id/blue" android:title="BLUE"></item>
<item android:id="@+id/gray" android:title="GRAY"></item>
<item android:id="@+id/cyan" android:title="CYAN"></item>
<item android:id="@+id/yellow" android:title="YELLOW"></item>
</menu>
显现
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.context_menu_demo"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.context_menu_demo.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>