Android基础-----Progress Dialog

ProgressDialog 是Android中很常用的处理后台线程显示前台界面的工具

package com.testprogressdialog;

import java.io.File;
import java.net.URLEncoder;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class TestProgressDialog extends Activity {
	private ProgressDialog dialog;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        dialog = new ProgressDialog(this);
		dialog.setMessage("运行中...");
		dialog.setIndeterminate(false);
		dialog.setCancelable(true);
		Button bt1=(Button)findViewById(R.id.button1);
		bt1.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				
				dialog.show();
				Thread thread = new Thread(new ThreadDemo());
				thread.start();	
				
			}
		});
    }
	    
	       final Handler handle = new Handler()
	    	{
	    		@Override
	    		public void handleMessage(Message msg) 
	    		{	
	    			if(dialog!=null)
	    			{
	    				dialog.dismiss();
	    			}
	    			if( msg.what>0 )
	    			{
	    				Toast.makeText(TestProgressDialog.this, "线程成功结束", Toast.LENGTH_SHORT).show();
	    			}
	    			else
	    			{
	    				Toast.makeText(TestProgressDialog.this, "线程出现意外", Toast.LENGTH_SHORT).show();
	    			}
	    		}   
	    	};
	    	
	        Handler endSessionHandle = new Handler()
	    	{
	    		@Override
	    		public void handleMessage(Message msg) 
	    		{	
	    			finish();
	    		}   
	    	};
	    	  class ThreadDemo implements Runnable
	          {	
	      		public void run() 
	      		{ 
	      			int what = -1;
	      			 try 
	                  {
	                  	for (int i=0;i<10;i++)
	                  {
	                  	
	                  	Thread.sleep(1000);
	                  	if (i==9)
	                  	{what=1;
	                  	}
	                  }
	               } 
	                  catch (Exception e) 
	                  {
	                  	e.printStackTrace();
	                  	Log.e("WeiboPub", e.getMessage());
	      			}	
	      			handle.sendEmptyMessage(what);
	      		}
	      	
	      }
 }
    	
      

另一种 :通过异步实现:

其实都是和线程操作有关的东西

thread的run()残缺返回值于是+handler组合就可以做出时候用户体验的界面+线程运作了

 

而asyn直接实现就可以了

 

class InitTask extends AsyncTask<Integer, Integer, String>{  

   //后面尖括号内分别是参数（例子里是线程休息时间），进度(publishProgress用到)，返回值 类型  

     

   @Override  

   protected void onPreExecute() {  

       //第一个执行方法  

   pdialog.show();

       super.onPreExecute();  

   }  

     

   @Override  

   protected String doInBackground(Integer... params) {  

       //第二个执行方法,onPreExecute()执行完后执行  

       initoken();

       return "初始化完毕,请继续操作!";  

   }  

 

   @Override  

   protected void onProgressUpdate(Integer... progress) {  

       //这个函数在doInBackground调用publishProgress时触发，虽然调用时只有一个参数  

       //但是这里取到的是一个数组,所以要用progesss[0]来取值  

       //第n个参数就用progress[n]来取值  

   

// if (progress[0] == 100)setTitle(R.string.app_name);

 

 

       super.onProgressUpdate(progress);  

   }  

 

   @Override  

   protected void onPostExecute(String result) {  

       //doInBackground返回时触发，换句话说，就是doInBackground执行完后触发  

       //这里的result就是上面doInBackground执行后的返回值，所以这里是"执行完毕"  

    pdialog.dismiss();

    setTitle(result); 

        super.onPostExecute(result);  

   }  

     

}  

 

这个的功能就是在线程运行时候显示progressdialog,线程结束dialog消失