菜单项单击android eclipse

Question

i am very new in android development (eclipse).i am try to do the following things. 1. generate a menu list when click on menu button in the eclipse 2. when clicking on the menu item navigate another page(xml page). i use the following codes.

menu.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<item android:id="@+id/about" android:title="About"/>
<item android:id="@+id/help" android:title="Help" />
</menu>

MainActivity.java

package com.example.menuoptions;

import com.example.menuoptions.R;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu, menu);
    return true;
}
public boolean onMenuItemClick(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.about:
    startActivity(new Intent(this, About.class));
    return true;
    case R.id.help:
    startActivity(new Intent(this, Help.class));
    return true;
    default:
    return super.onOptionsItemSelected(item);
    }
}
}

About.java

 package com.example.menuoptions;
 import android.app.Activity;
 import android.os.Bundle;
 public class About extends Activity {
  public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.about);

   }
  }

about.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
  android:orientation="vertical" >

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="About Page" />

</LinearLayout>

Problem is in my second need. The menu items are listed but when clicking on the about item it is not navigate to about.xml.

Answer 1

you should use this:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.about:
startActivity(new Intent(this, About.class));
return true;
case R.id.help:
startActivity(new Intent(this, Help.class));
return true;
default:
    return super.onOptionsItemSelected(item);
}
}

Answer 2

您是否在清单文件中提供了许可？

 <activity android:name=".About" />

Answer 3

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

simple code for menu selected

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle item selection
    switch (item.getItemId()) {
    case R.id.about:
        startActivity(new Intent(this, About.class));
        return true;
    case R.id.help:
        startActivity(new Intent(this, Help.class));
        return true;
    default:
        return super.onOptionsItemSelected(item);
    }
}

Try to use this