android 开发零起步学习笔记（二十九）：Android笔记：实现加载的progressDialog之后跳转到程序主界面

因为考虑到有些程序加载时间相对较长，所以在启动主界面之前，实现一个加载的progressDialog对话框来延缓，相对来说可以提高用户体验度。

如果是直接进入主界面，即activity，界面因为加载时间长，一片漆黑，让用户老觉得这程序不行。

贴出源码：

方法一：

1. public class LoadingActivity extends Activity { 
2.     private ProgressDialog dialog; 
3.     @Override 
4.     protected void onCreate(Bundle savedInstanceState) { 
5.             // TODO Auto-generated method stub 
6.             super.onCreate(savedInstanceState); 
7.             //设置一个progressdialog的弹窗 
8.             dialog = ProgressDialog.show(this, null, "程序正在加载，请稍候...", true, false); 
9.             //启动一个处理loading业务的线程 
10.             new LoadingThread(this).start(); 
11.     } 
12.  
13.     private class LoadingThread extends Thread { 
14.             private LoadingActivity activity; 
15.  
16.             public LoadingThread(LoadingActivity act) { 
17.                     Log.d(">>>>>LoadingThread", "构造方法"); 
18.                     activity = act; 
19.             } 
20.  
21.             public void run() { 
22.                     Log.d(">>>>>LoadingThread", "传递message"); 
23.                     //********************* 
24.                     //  处理业务 
25.                     //********************* 
26.                      
27.                     //发送消息 
28.                     activity.mHandler.sendEmptyMessage(0); 
29.             } 
30.     } 
31.      
32.     //处理跳转到主Activity 
33.     private Handler mHandler = new Handler() { 
34.             @Override 
35.             public void handleMessage(Message msg) { 
36.                     // TODO Auto-generated method stub 
37.                     Log.d(">>>>>Mhandler", "开始handleMessage"); 
38.                     Intent mIntent = new Intent(); 
39.                     mIntent.setClass(LoadingActivity.this, PalmHospital_main_Activity.class); 
40.                     startActivity(mIntent); 
41.                     LoadingActivity.this.finish(); 
42.                     Log.d(">>>>>Mhandler", "LoadActivity关闭"); 
43.                     if (dialog.isShowing()) 
44.                             dialog.dismiss(); 
45.             } 
46.     }; 
47. } 

public class LoadingActivity extends Activity {    private ProgressDialog dialog;    @Override    protected void onCreate(Bundle savedInstanceState) {            // TODO Auto-generated method stub            super.onCreate(savedInstanceState);            //设置一个progressdialog的弹窗            dialog = ProgressDialog.show(this, null, "程序正在加载，请稍候...", true, false);            //启动一个处理loading业务的线程            new LoadingThread(this).start();    }    private class LoadingThread extends Thread {            private LoadingActivity activity;            public LoadingThread(LoadingActivity act) {                    Log.d(">>>>>LoadingThread", "构造方法");                    activity = act;            }            public void run() {                    Log.d(">>>>>LoadingThread", "传递message");                //*********************                    //处理业务                //*********************                                        //发送消息                    activity.mHandler.sendEmptyMessage(0);            }    }        //处理跳转到主Activity    private Handler mHandler = new Handler() {            @Override            public void handleMessage(Message msg) {                    // TODO Auto-generated method stub                    Log.d(">>>>>Mhandler", "开始handleMessage");                    Intent mIntent = new Intent();                    mIntent.setClass(LoadingActivity.this, PalmHospital_main_Activity.class);                    startActivity(mIntent);                    LoadingActivity.this.finish();                    Log.d(">>>>>Mhandler", "LoadActivity关闭");                    if (dialog.isShowing())                            dialog.dismiss();            }    };}

方法二：相对来说要容易理解一点，贴图

1. public class LoadingActivity extends Activity { 
2.     private ProgressDialog dialog; 
3.     @Override 
4.     protected void onCreate(Bundle savedInstanceState) { 
5.             // TODO Auto-generated method stub 
6.             super.onCreate(savedInstanceState); 
7.             //设置一个progressdialog的弹窗 
8.             dialog = ProgressDialog.show(this, "加載中...", "正在搜尋。。。。，請稍後！"); 
9.             Thread thread = new Thread(new Runnable() { 
10.                     public void run() { 
11.                                                                  //do... 
12.                                                              
13.                             Message message = new Message(); 
14.                             message.what = 0; 
15.                             mHandler.sendMessage(message); 
16.                     } 
17.             }); 
18.             thread.start(); 
19.  
20.     } 
21.      
22.     //处理跳转到主Activity 
23.     private Handler mHandler = new Handler() { 
24.             @Override 
25.             public void handleMessage(Message msg) { 
26.                     // TODO Auto-generated method stub 
27.                     Log.d(">>>>>Mhandler", "开始handleMessage"); 
28.                     Intent mIntent = new Intent(); 
29.                     mIntent.setClass(LoadingActivity.this, PalmHospital_main_Activity.class); 
30.                     startActivity(mIntent); 
31.                     LoadingActivity.this.finish(); 
32.                     Log.d(">>>>>Mhandler", "LoadActivity关闭"); 
33.                     if (msg.what == 0) { 
34.                         dialog.dismiss(); 
35.                 } 
36.             } 
37.     }; 
38. }