android里面的自定义广播为什么注册不上呢

小弟有个问题，android里面的自定义广播为什么注册不上呢，在AndroidManifest里面已经写了<receiver>.public class Lianxi_custom_receiverActivity extends Activity 
{    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        
    
        
    }
    public void onClick_Send(View v)
    {
        
        Intent broadcastIntent=new Intent("zhou.disk.ABC4");
     broadcastIntent.addCategory("zhou.disk.mycategory4");
     broadcastIntent.putExtra("name", "zhouyu");
     this.sendBroadcast(broadcastIntent);
     Toast.makeText(this, "广播发送成功", Toast.LENGTH_LONG).show();
        
    }
    
}public class CustomReceiver2 extends BroadcastReceiver
{ @Override
public void onReceive(Context context, Intent intent)
{
if ("zhou.disk.ABC4".equals(intent.getAction()))
{
String name = intent.getStringExtra("name");
Toast.makeText(context, name, Toast.LENGTH_LONG).show(); } }}<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="zhou.disk"
    android:versionCode="1"
    android:versionName="1.0" >       <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:label="@string/app_name"
            android:name=".Lianxi_custom_receiverActivity" >
          <intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver android:name=".CustomReceiver2">
<intent-filter>
<action android:name="zhou.disk.ABC4" />
<category android:name="zhou.disk.mycategory4" />
</intent-filter>
</receiver>
</application>

 <uses-sdk android:minSdkVersion="9" />
</manifest>