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. */@Overridepublic 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() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubdialog.show();Thread thread = new Thread(new ThreadDemo());thread.start(); }});}final Handler handle = new Handler(){@Overridepublic 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(){@Overridepublic 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