//接口中定义这个方法,然后在实现类中实现他
- (void)imageSavedToPhotosAlbum:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *) contextInfo;

//实现类中实现
- (void)imageSavedToPhotosAlbum:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *) contextInfo {
    NSString *message;
    NSString *title;
    if (!error) {
        title = @"成功提示";
        message = @"成功保存到相";
    } else {
        title = @"失败提示";
        message = [error description];
    }
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title
                                                    message:message
                                                   delegate:nil
                                          cancelButtonTitle:@"知道了"
                                          otherButtonTitles:nil];
    [alert show];
    [alert release];
}

//调用方法保存到相册的代码
 UIImageWriteToSavedPhotosAlbum(img, self, @selector(imageSavedToPhotosAlbum: didFinishSavingWithError: contextInfo:), nil);

String path = imagePathText.getText().toString();
                     NetTool NTU=new NetTool();
                     String imagePath = NTU.getImagePath(getBaseContext(), path);
                     imageView.setImageBitmap(BitmapFactory.decodeFile(imagePath));

•  path  图片路径
•  NetTool  从网络获取图片的工具类
•  NetTool 主要的3个方法

• public class NetTool {
        static String TAG="step";
        public static InputStream getRequest(String path) throws Exception {
              URL url = new URL(/blog_article/path/index.html);
              HttpURLConnection conn = (HttpURLConnection) url.openConnection();
              conn.setRequestMethod("GET");
              conn.setConnectTimeout(5000); // 5秒
              if (conn.getResponseCode() == 200) {
                    return conn.getInputStream();
              }
              return null;
  
  
        }
  
  
        public static byte[] readInputStream(InputStream inStream) throws Exception {
              ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
              byte[] buffer = new byte[4096];
              int len = 0;
              while ((len = inStream.read(buffer)) != -1) {
                    outSteam.write(buffer, 0, len);
              }
              outSteam.close();
              inStream.close();
              return outSteam.toByteArray();
        }
  
  
        // 获取网络图片，如果缓存里面有就从缓存里面获取
        public static String getImagePath(Context context, String url) {
              if (url == null)
                    return "";
              String imagePath = "";
              String fileName = "";
  
  
              // 获取url中图片的文件名与后缀
              if (url != null && url.length() != 0) {
                    fileName = url.substring(url.lastIndexOf("/") + 1);
              }
  
  
              // 图片在手机本地的存放路径,注意：fileName为空的情况
              imagePath = context.getCacheDir() + "/" + fileName;
              Log.i(TAG, "imagePath = " + imagePath);
              File file = new File(context.getCacheDir(), fileName);// 保存文件,
              if (!file.exists()) {
                    Log.i(TAG, "file 不存在 ");
                    try {
                          byte[] data = readInputStream(getRequest(url));
                          Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0,
                                      data.length);
  
  
                          bitmap.compress(CompressFormat.JPEG, 100, new FileOutputStream(
                                      file));
  
  
                          imagePath = file.getAbsolutePath();
                          Log.i(TAG, "imagePath : file.getAbsolutePath() = " + imagePath);
  
  
                    } catch (Exception e) {
                          Log.e(TAG, e.toString());
                    }
              }
              return imagePath;
        } 
  }    

           

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