模拟文件拷贝:
要求：要用progressDialog和子线程来模拟显示拷贝进度；进度完成后在主界面提示拷贝完成，分别使用普通方式和消息机制编写。

layout文件：

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:tools="http://schemas.android.com/tools"
 4     android:layout_width="match_parent"
 5     android:layout_height="match_parent"
 6     android:paddingBottom="@dimen/activity_vertical_margin"
 7     android:paddingLeft="@dimen/activity_horizontal_margin"
 8     android:paddingRight="@dimen/activity_horizontal_margin"
 9     android:paddingTop="@dimen/activity_vertical_margin"
10     tools:context="com.hanqi.testapp2.PractiseActivity6"
11     android:orientation="vertical">
12 
13     <Button
14     android:layout_width="match_parent"
15     android:layout_height="wrap_content"
16     android:text="文件拷贝__普通方式"
17     android:onClick="bt_kaobei1"/>
18     <Button
19         android:layout_width="match_parent"
20         android:layout_height="wrap_content"
21         android:text="文件拷贝__消息机制"
22         android:onClick="bt_kaobei2"/>
23 </LinearLayout>

java类：

  1 package com.hanqi.testapp2;
  2 
  3 import android.app.ProgressDialog;
  4 import android.os.Bundle;
  5 import android.os.Handler;
  6 import android.os.Message;
  7 import android.support.v7.app.AppCompatActivity;
  8 import android.view.View;
  9 import android.widget.Toast;
 10 
 11 public class PractiseActivity6 extends AppCompatActivity {
 12 
 13     @Override
 14     protected void onCreate(Bundle savedInstanceState) {
 15         super.onCreate(savedInstanceState);
 16         setContentView(R.layout.activity_practise6);
 17     }
 18     public void bt_kaobei1(View v)
 19     {
 20         final ProgressDialog progressDialog = new ProgressDialog(this);
 21         progressDialog.setTitle("文件复制");
 22         progressDialog.setMessage("复制中，请等待……");
 23         progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
 24         progressDialog.setCancelable(false);
 25         progressDialog.show();
 26         new Thread(){
 27             @Override
 28             public void run() {
 29                 for (int i=0;i<=100;i++)
 30                 {
 31                     progressDialog.setProgress(i);
 32                     try {
 33                         Thread.sleep(3000);
 34                     }
 35                     catch (Exception e)
 36                     {
 37 
 38                     }
 39                 }
 40                 runOnUiThread(new Runnable() {
 41                     @Override
 42                     public void run() {
 43 
 44                         Toast.makeText(PractiseActivity6.this, "文件拷贝完成", Toast.LENGTH_SHORT).show();
 45                     }
 46                 });
 47                 progressDialog.dismiss();
 48             }
 49         }.start();
 50     }
 51     Handler h = new Handler(){
 52         @Override
 53         public void handleMessage(Message msg) {
 54             super.handleMessage(msg);
 55             if (msg.what ==1)
 56             {
 57                 final ProgressDialog progressDialog = new ProgressDialog(PractiseActivity6.this);
 58                 progressDialog.setTitle("文件复制");
 59                 progressDialog.setMessage("复制中，请等待……");
 60                 progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
 61                 progressDialog.setCancelable(false);
 62                 progressDialog.show();
 63                 new Thread(){
 64                     @Override
 65                     public void run() {
 66                         for (int i=0;i<=100;i++)
 67                         {
 68                             progressDialog.setProgress(i);
 69                             try {
 70                                 Thread.sleep(3000);
 71                             }
 72                             catch (Exception e)
 73                             {
 74 
 75                             }
 76                         }
 77                         runOnUiThread(new Runnable() {
 78                             @Override
 79                             public void run() {
 80 
 81                                 Toast.makeText(PractiseActivity6.this, "文件拷贝完成", Toast.LENGTH_SHORT).show();
 82                             }
 83                         });
 84                         progressDialog.dismiss();
 85                     }
 86                 }.start();
 87             }
 88         }
 89     };
 90     public void bt_kaobei2(View v)
 91     {
 92         new Thread(){
 93             @Override
 94             public void run() {
 95                 Message m = Message.obtain();
 96                 m.what = 1;
 97                 h.sendEmptyMessage(1);
 98             }
 99         }.start();
100     }
101 }

效果为：