《Android wireless Application Development》学习笔记1

1.Ctrl+Shift+o 组织导入 可以移除多余的导入，添加缺失的导入

2.Log.i("tag","msg")可以在logcat中打印一条消息，须加入import.util.Log;

3.运行了一个播放音乐的app

-1.导入相关包
import android.media.MediaPlayer;
import android.net.Uri;
-2.声明一个MediaPlayer对象
private MediaPlayer mp;
+3.在OnCreate事件中启动媒体播放器
   -private void startMediaPlayer()
        {
        	try
        	{
    		Log.i(DEBUG_TAG,"启动播放器");    		
    		Uri file=Uri.parse("http://www.342400.com/mp3/%ba%ec%be%fc%b0%a2%b8%e7%c4%e3%c2%fd%c2%fd%d7%df.mp3");
        		mp=MediaPlayer.create(this,file);                
        		mp.start();
        	}
        	catch(Exception e)
        	{
        		Log.e(DEBUG_TAG,"Player failed",e);
        	}
        }
+4.重载OnStop函数，释放资源
   -@Override
    	protected void onStop() {
        	if(mp!=null)
        	{
        		mp.stop();
        		mp.release();
        	}
    		super.onStop();
    	}

4.运行了一个获取位置信息的app

-1.导入相关包
import android.location.Location;
import android.location.LocationManager;
+2.在AndroidManifestr.xml的Permissions标签页添加Uses Permission
   -在右侧的面板中，选择android.permission.ACCESS_FINE_LOCATION
+3.在onCreate事件中调用如下函数
   -private void getLocation()
        {
        	try
        	{
        		LocationManager locMgr=(LocationManager)getSystemService(LOCATION_SERVICE);
        		Location recentLoc=locMgr.getLastKnownLocation(LocationManager.GPS_PROVIDER);
        		Log.i(DEBUG_TAG,"loc:"+recentLoc.toString());
        	}
        	catch(Exception e)
        	{
        		Log.e(DEBUG_TAG,"Location failed",e);
        	}
        }
+4.如果要跟实际设备连接，须将AndroidManifest.xml的Application页中Debuggable设为true
   -始终显示定位失败，不知道为啥