在android的开发过程中，经常遇到设置用户头像以及裁剪图像大小的功能。昨天我遇到了设置用户头像的功能，开始不知道怎么搞，在技术群里问也没人回答，就研究了微信、以及4399游戏中心用户设置头像的功能，了解到用户设置图像的过程，就是两步点击设置头像，选择头像资源的来源，相册和相机两个来得到。
闲话说的有点多了，来说说技术点吧。其实也比较简单，就是通过Intent来启动相册或者相机就可以了。
看下效果图：

启动相册以及相机关键代码：

1. switch (which) {  
2.                     case 0:
3. // 打开相册
4.                         Intent intentFromGallery = new Intent();  
5.                         intentFromGallery.setType("image/*"); // 设置文件类型  
6.                         intentFromGallery  
7.                                 .setAction(Intent.ACTION_GET_CONTENT);  
8.                         startActivityForResult(intentFromGallery,  
9.                                 IMAGE_REQUEST_CODE);  
10.                         break;  
11.                     case 1:  
12.   // 打开相机
13.                         Intent intentFromCapture = new Intent(  
14.                                 MediaStore.ACTION_IMAGE_CAPTURE);  
15.                         // 判断存储卡是否可以用，可用进行存储  
16.                         if (Tools.hasSdcard()) {  
17.  
18.                             intentFromCapture.putExtra(  
19.                                     MediaStore.EXTRA_OUTPUT,  
20.                                     Uri.fromFile(new File(Environment  
21.                                             .getExternalStorageDirectory(),  
22.                                             IMAGE_FILE_NAME)));  
23.                         }  
24.  
25.                         startActivityForResult(intentFromCapture,  
26.                                 CAMERA_REQUEST_CODE);  
27.                         break;  
28.                     } 

打开系统自带的裁剪功能代码：

1. /**  
2.      * 裁剪图片方法实现  
3.      *   
4.      * @param uri  
5.      */ 
6.     public void startPhotoZoom(Uri uri) {  
7.  
8.         Intent intent = new Intent("com.android.camera.action.CROP");  
9.         intent.setDataAndType(uri, "image/*");  
10.         // 设置裁剪  
11.         intent.putExtra("crop", "true");  
12.         // aspectX aspectY 是宽高的比例  
13.         intent.putExtra("aspectX", 1);  
14.         intent.putExtra("aspectY", 1);  
15.         // outputX outputY 是裁剪图片宽高  
16.         intent.putExtra("outputX", 320);  
17.         intent.putExtra("outputY", 320);  
18.         intent.putExtra("return-data", true);  
19.         startActivityForResult(intent, 2);  
20.     }  

完整实现代码如下：

1. package com.xzw.picture;  
2.  
3. import java.io.File;  
4.  
5. import com.xzw.utils.Tools;  
6.  
7. import android.app.Activity;  
8. import android.app.AlertDialog;  
9. import android.content.DialogInterface;  
10. import android.content.Intent;  
11. import android.graphics.Bitmap;  
12. import android.graphics.drawable.BitmapDrawable;  
13. import android.graphics.drawable.Drawable;  
14. import android.net.Uri;  
15. import android.os.Bundle;  
16. import android.os.Environment;  
17. import android.provider.MediaStore;  
18. import android.view.View;  
19. import android.view.Window;  
20. import android.widget.ImageView;  
21. import android.widget.RelativeLayout;  
22. import android.widget.Toast;  
23.  
24. /**  
25.  *   
26.  * @author XuZhiwei (xuzw13@gmail.com)  
27.  * Create at 2012-8-17 上午10:14:40  
28.  */ 
29. public class MainActivity extends Activity {  
30.     /*组件*/ 
31.     private RelativeLayout switchAvatar;  
32.     private ImageView faceImage;  
33.  
34.     private String[] items = new String[] { "选择本地图片", "拍照" };  
35.     /*头像名称*/ 
36.     private static final String IMAGE_FILE_NAME = "faceImage.jpg";  
37.       
38.     /* 请求码*/ 
39.     private static final int IMAGE_REQUEST_CODE = 0;  
40.     private static final int CAMERA_REQUEST_CODE = 1;  
41.     private static final int RESULT_REQUEST_CODE = 2;  
42.  
43.     @Override 
44.     public void onCreate(Bundle savedInstanceState) {  
45.         super.onCreate(savedInstanceState);  
46.         requestWindowFeature(Window.FEATURE_NO_TITLE); // 去掉标题  
47.         setContentView(R.layout.main);  
48.         switchAvatar = (RelativeLayout) findViewById(R.id.switch_face_rl);  
49.         faceImage = (ImageView) findViewById(R.id.face);  
50.         //设置事件监听  
51.         switchAvatar.setOnClickListener(listener);  
52.     }  
53.      
54.     private View.OnClickListener listener = new View.OnClickListener() {  
55.  
56.         @Override 
57.         public void onClick(View v) {  
58.             showDialog();  
59.         }  
60.     };  
61.     /**  
62.      * 显示选择对话框  
63.      */ 
64.     private void showDialog() {  
65.           
66.         new AlertDialog.Builder(this)  
67.                 .setTitle("设置头像")  
68.                 .setItems(items, new DialogInterface.OnClickListener() {  
69.  
70.                     @Override 
71.                     public void onClick(DialogInterface dialog, int which) {  
72.                         switch (which) {  
73.                         case 0:  
74.                             Intent intentFromGallery = new Intent();  
75.                             intentFromGallery.setType("image/*"); // 设置文件类型  
76.                             intentFromGallery  
77.                                     .setAction(Intent.ACTION_GET_CONTENT);  
78.                             startActivityForResult(intentFromGallery,  
79.                                     IMAGE_REQUEST_CODE);  
80.                             break;  
81.                         case 1:  
82.  
83.                             Intent intentFromCapture = new Intent(  
84.                                     MediaStore.ACTION_IMAGE_CAPTURE);  
85.                             // 判断存储卡是否可以用，可用进行存储  
86.                             if (Tools.hasSdcard()) {  
87.  
88.                                 intentFromCapture.putExtra(  
89.                                         MediaStore.EXTRA_OUTPUT,  
90.                                         Uri.fromFile(new File(Environment  
91.                                                 .getExternalStorageDirectory(),  
92.                                                 IMAGE_FILE_NAME)));  
93.                             }  
94.  
95.                             startActivityForResult(intentFromCapture,  
96.                                     CAMERA_REQUEST_CODE);  
97.                             break;  
98.                         }  
99.                     }  
100.                 })  
101.                 .setNegativeButton("取消", new DialogInterface.OnClickListener() {  
102.  
103.                     @Override 
104.                     public void onClick(DialogInterface dialog, int which) {  
105.                         dialog.dismiss();  
106.                     }  
107.                 }).show();  
108.  
109.     }  
110.       
111.     @Override 
112.     protected void onActivityResult(int requestCode, int resultCode, Intent data) {  
113.      //结果码不等于取消时候 if (resultCode != RESULT_CANCELED) {   
114.  switch (requestCode) {  
115.         case IMAGE_REQUEST_CODE:  
116.             startPhotoZoom(data.getData());  
117.             break;  
118.         case CAMERA_REQUEST_CODE:  
119.             if (Tools.hasSdcard()) {  
120.                 File tempFile = new File(  
121.                         Environment.getExternalStorageDirectory()  
122.                                 + IMAGE_FILE_NAME);  
123.                 startPhotoZoom(Uri.fromFile(tempFile));  
124.             } else {  
125.                 Toast.makeText(MainActivity.this, "未找到存储卡，无法存储照片！",  
126.                         Toast.LENGTH_LONG).show();  
127.             }  
128.  
129.             break;  
130.         case RESULT_REQUEST_CODE:  
131.             if (data != null) {  
132.                 getImageToView(data);  
133.             }  
134.             break;  
135.         }  
136. }
137.         super.onActivityResult(requestCode, resultCode, data);  
138.     }  
139.  
140.     /**  
141.      * 裁剪图片方法实现  
142.      *   
143.      * @param uri  
144.      */  
145.     public void startPhotoZoom(Uri uri) {  
146.  
147.         Intent intent = new Intent("com.android.camera.action.CROP");  
148.         intent.setDataAndType(uri, "image/*");  
149.         // 设置裁剪  
150.         intent.putExtra("crop", "true");  
151.         // aspectX aspectY 是宽高的比例  
152.         intent.putExtra("aspectX", 1);  
153.         intent.putExtra("aspectY", 1);  
154.         // outputX outputY 是裁剪图片宽高  
155.         intent.putExtra("outputX", 320);  
156.         intent.putExtra("outputY", 320);  
157.         intent.putExtra("return-data", true);  
158.         startActivityForResult(intent, 2);  
159.     }  
160.  
161.     /**  
162.      * 保存裁剪之后的图片数据  
163.      *   
164.      * @param picdata  
165.      */  
166.     private void getImageToView(Intent data) {  
167.         Bundle extras = data.getExtras();  
168.         if (extras != null) {  
169.             Bitmap photo = extras.getParcelable("data");  
170.             Drawable drawable = new BitmapDrawable(photo);  
171.             faceImage.setImageDrawable(drawable);  
172.         }  
173.     }  
174.  
175. }  

还有一个工具类：

1. package com.xzw.utils;  
2.  
3. import android.os.Environment;  
4. /**  
5.  *   
6.  * @author XuZhiwei (xuzw13@gmail.com)  
7.  * Create at 2012-8-17 上午10:14:40  
8.  */ 
9. public class Tools {  
10.     /**  
11.      * 检查是否存在SDCard  
12.      * @return  
13.      */ 
14.     public static boolean hasSdcard(){  
15.         String state = Environment.getExternalStorageState();  
16.         if(state.equals(Environment.MEDIA_MOUNTED)){  
17.             return true;  
18.         }else{  
19.             return false;  
20.         }  
21.     }  
22. }  

本文转自xuzw13 51CTO博客，原文链接：http://blog.51cto.com/xuzhiwei/965511，如需转载请自行联系原作者