Android開發之使用RatingBar設置游戲難度並保存

最近在學習游戲開發，在游戲中常常需要設置游戲的難度，在Android中我們可以使用RatingBar來實現。具體看下面的代碼：

效果圖如下：

1. package com.cloay.pt.ui;  
2.   
3. import java.io.FileNotFoundException;  
4. import java.io.IOException;  
5.   
6. import android.content.ContentResolver;  
7. import android.content.Intent;  
8. import android.content.SharedPreferences;  
9. import android.graphics.Bitmap;  
10. import android.graphics.BitmapFactory;  
11. import android.net.Uri;  
12. import android.os.Bundle;  
13. import android.view.View;  
14. import android.view.View.OnClickListener;  
15. import android.widget.ImageView;  
16. import android.widget.RatingBar;  
17. import android.widget.RatingBar.OnRatingBarChangeListener;  
18. import android.widget.TextView;  
19.   
20. import com.cloay.pt.BasicActivity;  
21. import com.cloay.pt.R;  
22. import com.cloay.pt.constants.Constant;  
23. import com.cloay.pt.utils.ImageUtil;  
24.   
25. /** 
26.  * 游戲設置類,游戲難度等 
27.  * @author Cloay 
28.  * 2011-12-23 
29.  * 下午05:21:41 
30.  */  
31. public class SettingsActivity extends BasicActivity{  
32.     private SharedPreferences settings;  //保存設置   
33.     private RatingBar ratingBar;  
34.     private TextView defaultPicture;  
35.     private TextView picture;  
36.     private ImageView previewImage;  
37.     @Override  
38.     protected void onCreate(Bundle savedInstanceState) {  
39.         super.onCreate(savedInstanceState);  
40.         setContentView(R.layout.settings);  
41.         BasicActivity.allActivity.add(this);  
42.         //初始化數據   
43.         initData();  
44.     }  
45.       
46.     /** 
47.      * 初始化數據 
48.      */  
49.     private void initData() {  
50.         settings = getSharedPreferences("settings", 0);  
51.         ratingBar = (RatingBar) findViewById(R.id.rating);  
52.         //游戲默認圖片   
53.         defaultPicture = (TextView) findViewById(R.id.def);  
54.         //從圖庫中選擇圖片，自定義   
55.         picture = (TextView) findViewById(R.id.picture);  
56.         previewImage = (ImageView)findViewById(R.id.preview);  
57.         if("".equals(settings.getString("picture", ""))) {  
58.             previewImage.setImageResource(R.drawable.def);  
59.         }else{  
60.             previewImage.setImageBitmap(ImageUtil.getBitmapFromSDCard(settings.getString("picture", "")));  
61.         }  
62.         //設置難度選擇監聽   
63.         ratingBar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {  
64.             @Override  
65.             public void onRatingChanged(RatingBar ratingBar, float rating,  
66.                     boolean fromUser) {  
67.                 settings.edit().putInt("level", (int)rating).commit();   //保存用戶設置後的游戲難度   
68.                 showToast(SettingsActivity.this, (int)rating);  
69.             }  
70.         });  
71.         //設置圖片選擇監聽   
72.         defaultPicture.setOnClickListener(new OnClickListener() {  
73.             @Override  
74.             public void onClick(View v) {  
75.                 settings.edit().putString("picture", "").commit();  
76.                 previewImage.setImageResource(R.drawable.def);  
77.             }  
78.         });  
79.         picture.setOnClickListener(new OnClickListener() {  
80.             @Override  
81.             public void onClick(View v) {  
82.                 Intent intent = new Intent();    
83.                 /* 開啟Pictures畫面Type設定為image */    
84.                 intent.setType("image/*");    
85.                 /* 使用Intent.ACTION_GET_CONTENT這個Action */    
86.                 intent.setAction(Intent.ACTION_GET_CONTENT);   
87.                 /* 取得相片後返回本畫面 */    
88.                 startActivityForResult(intent, 1);  
89.             }  
90.         });  
91.           
92.     }  
93.       
94.     @Override  
95.     protected void onActivityResult(int requestCode, int resultCode, Intent data) {  
96.         if (resultCode == RESULT_OK) {    
97.             Uri uri = data.getData();    
98.             ContentResolver cr = this.getContentResolver();    
99.             try {    
100.                 Bitmap bitmap = BitmapFactory.decodeStream(cr.openInputStream(uri));    
101.                 try {  
102.                     saveBitmap("cloay", bitmap);  
103.                 } catch (IOException e) {  
104.                     e.printStackTrace();  
105.                 }  
106.                 settings.edit().putString("picture", Constant.picPath + "cloay.png").commit();  
107.                 previewImage.setImageBitmap(bitmap);  
108.             } catch (FileNotFoundException e) {    
109.                 settings.edit().putString("picture", "").commit();  
110.                 previewImage.setImageResource(R.drawable.def);  
111.             }    
112.         }   
113.         super.onActivityResult(requestCode, resultCode, data);  
114.     }  
115. }  

通過設置setOnRatingBarChangeListener監聽器來獲取用戶選擇RatingBar的值，獲取之後往往需要保存，通常使用SharedPrefence即可，也可選用SQLite等。SharedPrefence的使用詳細請看: Android SharedPreferences的使用 http://www.linuxidc.com/Linux/2011-11/48029.htm