Android从一个应用启动另一个主界面隐藏图标的应用

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.rainwii.message"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.rainwii.message.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <!--这句可以注释掉，也可以留着-->
               <!--  <category android:name="android.intent.category.LAUNCHER" /> -->
               <!--data是关键的；android:scheme代码可以注释。如果想写内容随便写，但是和要和a应用中的跳转信息一致-->
                <data  android:host="MainActivity"  
                  android:scheme="abc"     
                  />
            </intent-filter>
        </activity>
      
    </application>

</manifest>

package com.rainwii.main;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {
Button startappbutton;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        startappbutton= (Button) findViewById(R.id.button1);
        startappbutton.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent intent = new Intent();
                ComponentName cn = new ComponentName("com.rainwii.message",
                        "com.rainwii.message.MainActivity");
                intent.setComponent(cn);
                Uri uri = Uri.parse("abc");// 此处应与B程序中Data中标签一致
                intent.setData(uri);
                startActivity(intent);
            }
        });
              
      
    }


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

Intent it=new Intent();
it.setComponent(new ComponentName(String packageName,String activityName ));
startActivity(it);