android UI之button異步處理

在作界面時候，咱們常常用到button，可是好多時候咱們直接把響應事件寫在在了Onclick函數裏面。可是這樣作的壞處就是佔用了ui線程。若是是請求數據庫或者是進行網絡數據請求，那麼這樣作可能會有點得不償失。

Button testButton = new Button(this);

testButton .setOnClickListener(new OnclickListener(){
           public void onClick(View view){

                // do something

           }
        });

因此在UI處理的時候，咱們應該儘可能作到異步處理。也就是起咱們本身的處理線程。

import android.content.*;
import android.graphics.*;
import android.net.*;
import android.os.Handler;
import android.os.Message;
import android.view.*;
import android.widget.*;

import com.sc.lib.Base64;
import com.sc.lib.ui.BusyDialog;
import com.sc.netvision.TopCommander;
import com.sc.netvision.Utils;
import com.sc.netvision.xml.*;

public class videoPlay extends LinearLayout implements
          Runnable ,View.OnClickListener{
    private VideoView mPlayer = null;
    private String path = null;
    private Button playButton = null;
    private BusyDialog dlgBusy = null;
 private final int FAILCONNECTSERVER = 1;
 private final int PLAYMEDIAVIEW = 20;
 
    public ClipVideoPlay( Context context, String loadPath) {
 
  super(context);
  initial( context);
  path = loadPaht;
  
 }
  private Handler  uiHandler = new Handler()  {
 
  public void handleMessage(Message msg) {
   try {
    switch (msg.what) {
     case FAILCONNECTSERVER:
      Toast.makeText(currentContext, "Can not connect to server",
               Toast.LENGTH_SHORT).show();
      break;     
     case PLAYMEDIAVIEW:
      playMedia(currentContext);
     default:
      super.handleMessage(msg);
      break;
    }
   } finally {
    dlgBusy.cancel();
   }
  }
 };
    public void onClick(View view) {
     // TODO Auto-generated method stub
     isPlay = false;
     if(view == playButton) {
      dlgBusy = BusyDialog.showBusyDialog(currentContext, "Please wait", "Returning ...");
      new Thread(this).start();
     }
    }
 
    public void run() {
     // TODO Auto-generated method stub
     Message msg = new Message();  
  try {
  
   msg.what = PLAYMEDIAVIEW; 
  
  } finally {
   
   uiHandler.sendMessage(msg);
  }   
    }
   private void initial( Context context) {
 
   setOrientation(VERTICAL);
  currentContext = context;
  clipList = clips;
  deviceName = devName;
  
  
  playButton = new Button(context);
  playButton.setOnClickListener(this);     
  path = URL;
  mPlayer = new VideoView(context);
  
  addView(playButton,new LinearLayout.LayoutParams(
      LinearLayout.LayoutParams.FILL_PARENT,
      LinearLayout.LayoutParams.WRAP_CONTENT));
  addView(addPlayTitle(context));
  addView(mPlayer,new LinearLayout.LayoutParams(
      LinearLayout.LayoutParams.FILL_PARENT,
      LinearLayout.LayoutParams.FILL_PARENT));
  setGravity(Gravity.CENTER);      
 }
  
   
 private void playMedia(Context context) {
   String uriPath = path ;
  Uri uri = Uri.parse(uriPath);
  MediaController controller = new MediaController(context);
  controller.show();
  mPlayer.setMediaController(controller);
  mPlayer.setVideoURI(uri);
  mPlayer.requestFocus();
  mPlayer.start();
    }

}

代碼不能直接運行。 可是思想是這個思想。另起一個線程去獲取網絡數據，進行播放。這樣能夠快速響應事件。