Android 程式開發：（一）詳解活動 —— 1.6 顯示複雜對話方塊

除了“對話方塊”進度條，也可以建立一個顯示“操作進度”的對話方塊，例如顯示正在下載的狀態。

1. 建立一個工程：Dialog。

2. main.xml中的代碼。

[java] view plaincopy

1. <?xml version="1.0" encoding="utf-8"?>  
2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
3.     android:layout_width="fill_parent"  
4.     android:layout_height="fill_parent"  
5.     android:orientation="vertical" >  
6.   
7.     <Button  
8.         android:id="@+id/btn_dialog3"  
9.         android:layout_width="fill_parent"  
10.         android:layout_height="wrap_content"  
11.         android:onClick="onClick3"  
12.         android:text="Click to display a detailed progress dialog" />  
13.   
14. </LinearLayout>  

3. DialogActivity.java中的代碼。[java] view plaincopy

1. public class DialogActivity extends Activity {  
2.     ProgressDialog progressDialog;  
3.   
4.     /** Called when the activity is first created. */  
5.     @Override  
6.     public void onCreate(Bundle savedInstanceState) {  
7.         super.onCreate(savedInstanceState);  
8.         setContentView(R.layout.main);  
9.     }  
10.   
11.     public void onClick3(View v) {  
12.         showDialog(1);  
13.         progressDialog.setProgress(0);  
14.   
15.         new Thread(new Runnable() {  
16.             public void run() {  
17.                 for (int i = 1; i <= 15; i++) {  
18.                     try {  
19.                         // ---simulate doing something lengthy---  
20.                         Thread.sleep(1000);  
21.                         // ---update the dialog---  
22.                         progressDialog.incrementProgressBy((int) (100 / 15));  
23.                     } catch (InterruptedException e) {  
24.                         e.printStackTrace();  
25.                     }  
26.                 }  
27.                 progressDialog.dismiss();  
28.             }  
29.         }).start();  
30.     }  
31.   
32.     @Override  
33.     protected Dialog onCreateDialog(int id) {  
34.         switch (id) {  
35.         case 1:  
36.             progressDialog = new ProgressDialog(this);  
37.             progressDialog.setIcon(R.drawable.ic_launcher);  
38.             progressDialog.setTitle("Downloading files...");  
39.             progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);  
40.             progressDialog.setButton(DialogInterface.BUTTON_POSITIVE, "OK",  
41.                     new DialogInterface.OnClickListener() {  
42.                         public void onClick(DialogInterface dialog,  
43.                                 int whichButton) {  
44.                             Toast.makeText(getBaseContext(), "OK clicked!",  
45.                                     Toast.LENGTH_SHORT).show();  
46.                         }  
47.                     });  
48.             progressDialog.setButton(DialogInterface.BUTTON_NEGATIVE, "Cancel",  
49.                     new DialogInterface.OnClickListener() {  
50.                         public void onClick(DialogInterface dialog,  
51.                                 int whichButton) {  
52.                             Toast.makeText(getBaseContext(), "Cancel clicked!",  
53.                                     Toast.LENGTH_SHORT).show();  
54.                         }  
55.                     });  
56.             return progressDialog;  
57.         }  
58.         return null;  
59.     }  
60. }  

4. 按F11調試。

想要建立一個顯示進度的對話方塊，首先要建立一個ProgressDialog類的執行個體，然後設定各種狀態，表徵圖、標題、樣式等等：

[java] view plaincopy

1. progressDialog = new ProgressDialog(this);  
2. progressDialog.setIcon(R.drawable.ic_launcher);  
3. progressDialog.setTitle("Downloading files...");  
4. progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);  

然後設定兩個按鈕：[java] view plaincopy

1. progressDialog.setButton(DialogInterface.BUTTON_POSITIVE, "OK",  
2.         new DialogInterface.OnClickListener() {  
3.             public void onClick(DialogInterface dialog,  
4.                     int whichButton) {  
5.                 Toast.makeText(getBaseContext(), "OK clicked!",  
6.                         Toast.LENGTH_SHORT).show();  
7.             }  
8.         });  
9. progressDialog.setButton(DialogInterface.BUTTON_NEGATIVE, "Cancel",  
10.         new DialogInterface.OnClickListener() {  
11.             public void onClick(DialogInterface dialog,  
12.                     int whichButton) {  
13.                 Toast.makeText(getBaseContext(), "Cancel clicked!",  
14.                         Toast.LENGTH_SHORT).show();  
15.             }  
16.         });  

使用一個線程顯示進度條的狀態：[java] view plaincopy

1. progressDialog.setProgress(0);  
2.   
3. new Thread(new Runnable() {  
4.     public void run() {  
5.         for (int i = 1; i <= 15; i++) {  
6.             try {  
7.                 // ---simulate doing something lengthy---  
8.                 Thread.sleep(1000);  
9.                 // ---update the dialog---  
10.                 progressDialog.incrementProgressBy((int) (100 / 15));  
11.             } catch (InterruptedException e) {  
12.                 e.printStackTrace();  
13.             }  
14.         }  
15.         progressDialog.dismiss();  
16.     }  
17. }).start();  

當進度條到達100%的時候，它就被解除了。