调用其他程序可以直接使用ComponentName，但有些需要调用Action才行

//可以正常打开

Intent intent=new Intent();
    intent.setComponent(new ComponentName("com.android.mms", "com.android.mms.ui.ConversationList")); 
    M.this.startActivity(intent);

//调用照相机
下面会报错：

Intent intent=new Intent();
intent.setComponent(new ComponentName("com.android.camera", "com.android.camera.CameraEntry"));  
 M.this.startActivity(intent);

//直接调用Action就可以调用照相机

Intent intent = new Intent(); 

intent.setAction("android.media.action.STILL_IMAGE_CAMERA");
startActivity(intent);

  前面已经出了一个展示地图的例子，这个例子主要运用了将地图的放在txt上面，然后读取尽力啊，在j2me中是直接获取，而在android中text放在assets文件夹中，通过AssetManager来获取。应为我已经写出了android版的java me的游戏包，那么转化这些东西就很简单了。

下面给出效果图和代码:

 MainView.java

package com.wjh.demon_12;

import java.io.InputStream;

import com.wjh.midp_me.AndroidLayerManager;
import com.wjh.midp_me.AndroidSprite;
import com.wjh.midp_me.AndroidTiledLayer;

import android.content.Context;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.KeyEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.SurfaceHolder.Callback;

public class MainView extends SurfaceView implements Callback,Runnable{
	int keyCode = 0;
	String keyAction = "";
	Thread gameThread = null;
	boolean isGame = true;
	SurfaceHolder holder = null;

	
	Paint backPaint = null;
	Paint forePaint = null;
	
	//具体游戏相关 
	public AndroidTiledLayer m_TLayer;				//管理场景
	public AndroidSprite m_ManSprite;				//用于显示精灵动画
	public AndroidLayerManager m_Manager;			//图层管理器，管理各个图层
	public int m_nX = 0;					//显示区域左上角的横坐标
	public int m_nY = 0;  
	
	//资源管理
	AssetManager assetManager = null;
	public MainView(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
		setFocusable(true);
		getHolder().addCallback(this);
		holder = this.getHolder();
			
			
			backPaint = new Paint();
			backPaint.setColor(Color.BLACK);
			forePaint = new Paint();
			
			assetManager = context.getAssets();
			
			//读取tile图片
			Bitmap image = BitmapFactory.decodeResource(context.getResources(), R.drawable.map);
			//创建TiledLayer场景
			m_TLayer = new AndroidTiledLayer( 8, 8, image, 32, 32 ); 
			//设置场景的位置
			m_TLayer.setPosition( 0, 0 ); 
			LoadMap();
			
			//读取精灵图片，创建精灵，精灵的像素大小为27*36
			Bitmap image2 = BitmapFactory.decodeResource(context.getResources(), R.drawable.man);
			m_ManSprite = new AndroidSprite( image2, 27, 36 );
			//设置精灵左上角的位置		
			m_ManSprite.setPosition( 80 , 80 );	
			
			//将各个图层添入m_Manager
			m_Manager = new AndroidLayerManager();
			m_Manager.append(m_ManSprite);
			m_Manager.append(m_TLayer);
			//设置m_Manager的显示区域
			m_Manager.setViewWindow( m_nX, m_nY, getWidth(), getHeight() );
		
	}
	public void LoadMap(){
		try{
			
			InputStream is =   assetManager.open("map.txt");         
			int row = 0;						//行号
			int col = 0;						//列号
			int ch = is.read();	 				//读取一个字节的数据
			while( ch != -1 ){					//当读到文件末尾时，返回-1
				if( ch == '\n' && row < 7 ){	//修正行列号
					row ++;
					col = 0;
				}
				else if( ch > '0' && ch < '5' )
				{//如果是符合需要的数据
					m_TLayer.setCell( row, col, ch - '0' );
					if( col < 7 )
						col ++;
				}
				ch = is.read();					//读取下一数据
			}
			is.close();							//释放资源
		}
		catch (Exception e){
			e.printStackTrace();				//显示错误信息
		}
	}
	@Override
	public void run() {
		//获取系统当前时间，并将时间换算成以毫秒为单位的数
		long T1 = System.currentTimeMillis();
		long T2 = T1;
		while(isGame){
			T2 = System.currentTimeMillis();
			if( T2 - T1 > 100 ){			    //间隔100毫秒
				T1 = T2;
				input();
				logic();
				doDraw();
			}
		}
		
	}
	//开始游戏主线程
	public void start()
	{
		if(gameThread == null)
		{
		gameThread = new Thread(this);
		gameThread.start();
		}
	}
	//停止游戏主线程
	public void stop()
	{
		isGame = false;
		if(gameThread != null)
		{
			try {
				gameThread.join();
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	//输入判断
	public void input()
	{	

		boolean m_bKeyDown = false;           //有无按键的标志
		//如果按下方向键的上键，则显示区域向上移动
		if( keyCode == KeyEvent.KEYCODE_DPAD_UP ){
			m_nY -= 2; 
			m_bKeyDown = true;
		}
		//如果按下方向键的下键，则显示区域向下移动
		if( keyCode == KeyEvent.KEYCODE_DPAD_DOWN ){
			m_nY += 2;
			m_bKeyDown = true;
		}	
		//如果按下方向键的左键，则显示区域向左移动
		if( keyCode == KeyEvent.KEYCODE_DPAD_LEFT ){
			m_nX -= 2; 
			m_bKeyDown = true;
		}
		//如果按下方向键的右键，则显示区域向右移动
		if(keyCode == KeyEvent.KEYCODE_DPAD_RIGHT ){
			m_nX += 2;
			m_bKeyDown = true;
		}
		if( m_bKeyDown ){
			//调整显示区域，使显示区域不超出场景
			if( m_nX < 0 )
				m_nX = 0;
			//m_TLayer中存储的场景图像的宽度为8*32，高度也为8*32
			if( m_nX > getWidth()-8*32 )
				m_nX = getWidth()-8*32;
			if( m_nY < 0 )
				m_nY = 0;
			if( m_nY > getHeight()-8*32 )
				m_nY = getHeight()-8*32;
			//重新设置显示区域
			m_Manager.setViewWindow( m_nX, m_nY, getWidth(), getHeight() );
		}
		keyCode = -1;

	}
	public long m_LogicT1 = System.currentTimeMillis();
	//逻辑判断
	public void logic()
	{
		//更换精灵当前显示的“帧”编号，“帧”编号不能大于上限
		int n = m_ManSprite.getFrame();
		n ++;
		//getFrameSequenceLength可获取精灵图像中“帧”的个数
		if( n >= m_ManSprite.getFrameSequenceLength() )
			n = 0;
		m_ManSprite.setFrame(n);
	}
	public void doDraw()
	{
		Canvas c = null;
		try
		{
		c = holder.lockCanvas();
		synchronized (holder) {
			paint(c);
		}
		}finally{
			if(c != null)
			{
			holder.unlockCanvasAndPost(c);
			}
		}
	}
	//画图
	public void paint(Canvas canvas)
	{
		//用黑色清屏
		canvas.drawRect(0, 0, getWidth(), getHeight(), backPaint);
		
		//从屏幕的(0,0)点开始显示图像
		m_Manager.paint(canvas, forePaint);
		

	}
	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width,
			int height) {
		// TODO Auto-generated method stub
		
	}
	@Override
	public void surfaceCreated(SurfaceHolder holder) {
		// TODO Auto-generated method stub
		start();
		
	}
	@Override
	public void surfaceDestroyed(SurfaceHolder holder) {
		// TODO Auto-generated method stub
		stop();
		
	}
	@Override
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		// TODO Auto-generated method stub
		this.keyCode = keyCode;
		return true;
	}
	

}

apk文件(将后缀改为apk):Demon_12.zip

源代码:Demon_12.rar

public class CH03_12 extends Activity {
	/** Called when the activity is first created. */
	private Button btn;
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		btn = (Button)findViewById(R.id.btn);
		btn.setOnClickListener(new BtnClick());
		
	}
	
	//事件
	class BtnClick implements OnClickListener
	{
		@Override
		public void onClick(View v) 
		{
			//设置弹出对话框的地方
			new AlertDialog.Builder(CH03_12.this).setTitle("提示").setMessage("您好").setPositiveButton
			(
					"您确定?",
					new DialogInterface.OnClickListener() {
						@Override
						public void onClick(DialogInterface dialog, int which) {
							// 这里写当对对话框点击之后要执行的代码
							//finish(); //这里执行离开程序
						}
					}
			).show();
			
		}
	}
}