iOS图片上传及压缩

iOS开发中关于图片上传，一般有两种方法:
1.自己手动写（如：NSURLMutableRequest等系统类），实现起来比较复杂，暂且不提
2.使用第三方（如：主流的AFNetworking），在开发中使用第三方比较多，下面就是使用AFN上传图片的流程：

//获取图片
-(void)avatarTap:(id)sender{
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"设置头像" message:@"" preferredStyle:UIAlertControllerStyleAlert];

//取消
UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
NSLog(@"The \"Okay/Cancel\" alert's cancel action occured.");
}];

UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
imagePicker.allowsEditing = YES;
imagePicker.delegate = self;

//从相册中选择
UIAlertAction* fromPhotosAlbumAction = [UIAlertAction actionWithTitle:@"从相册选择" style:UIAlertActionStyleDefault  handler:^(UIAlertAction * action) {       
imagePicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
[self presentViewController:imagePicker animated:YES completion:nil];
}];

//从图库选择
UIAlertAction* fromPhotoAction = [UIAlertAction actionWithTitle:@"从图库选择" style:UIAlertActionStyleDefault  handler:^(UIAlertAction * action) {                              
imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
[self presentViewController:imagePicker animated:YES completion:nil];
}];

//相机拍摄
UIAlertAction* fromCameraAction = [UIAlertAction actionWithTitle:@"相机拍摄" style:UIAlertActionStyleDefault  handler:^(UIAlertAction * action) {
if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]){
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentViewController:imagePicker animated:YES completion:nil]; }
}];

[alertController addAction:cancelAction];
[alertController addAction:fromCameraAction];
[alertController addAction:fromPhotoAction];
[alertController addAction:fromPhotosAlbumAction];
[self presentViewController:alertController animated:YES completion:nil];
}

//如何进行压缩
//将图片尺寸改为240x240
UIImage *smallImage=[self scaleFromImage:image toSize:CGSizeMake(240.0f, 240.0f)];
//写入jpg文件
[UIImageJPEGRepresentation(smallImage, 1.0f) writeToFile:imageFilePath atomically:YES];

//+ (UIImage *)imageWithCGImage:(CGImageRef)cgImage scale:(CGFloat)scale orientation:(UIImageOrientation)orientation NS_AVAILABLE_IOS(4_0);**
//该方法使用一个CGImageRef创建UIImage，在创建时还可以指定放大倍数以及旋转方向。当scale设置为1的时候，新创建的图像将和原图像尺寸一摸一样，而orientaion则可以指定新的图像的绘制方向。
//也可以用这个方法进行压缩你会发现得到的大小会小了很多倍，如果想测试的话可以转换成 NSData 打印一下。

//获取压缩后的图片
+ (UIImage *) scaleFromImage: (UIImage *) imagetoSize: (CGSize)size{
UIGraphicsBeginImageContext(size);
[image drawInRect:CGRectMake(0, 0, size.width, size.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}

#pragma mark - 图片上传
//上传图片(单张)
+(void)uploadPhotoAndController:(UIViewController *)controller WithSize:(CGSize)size Image:(UIImage*)image AndFinish:(void (^)(NSDictionary *, NSError *))finish
{
    //加载提示菊花
    MBProgressHUD *hud;
    if(controller){
        hud = [MBProgressHUD showHUDAddedTo:controller.view animated:YES];
        hud.label.text = NSLocalizedString(@"加载中...", @"HUD loading title");
    }
    
    //1. 存放图片的服务器地址，这里我用的宏定义
    NSString * url = [NSString stringWithFormat:@"%@%@",Hx_Main_heard_API,IMAGE_UPLOAD_URL_API];
    
    //2. 利用时间戳当做图片名字
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    formatter.dateFormat = @"yyyyMMddHHmmss";
    NSString *imageName = [formatter stringFromDate:[NSDate date]];
    NSString *fileName = [NSString stringWithFormat:@"%@.jpg",imageName];
    
    //3. 图片二进制文件
    NSData *imageData = UIImageJPEGRepresentation(image, 0.7f);
    NSLog(@"upload image size: %ld k", (long)(imageData.length / 1024));
    
    //4. 发起网络请求
    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    manager.requestSerializer = [AFHTTPRequestSerializer serializer];
    manager.responseSerializer = [AFJSONResponseSerializer serializer];
    [manager POST:url parameters:nil constructingBodyWithBlock:^(id formData) {
        // 上传图片，以文件流的格式，这里注意：name是指服务器端的文件夹名字
        [formData appendPartWithFileData:imageData name:@"file" fileName:fileName mimeType:@"image/jpeg"];
    } success:^(AFHTTPRequestOperation *operation, id responseObject) {
        //上传成功时的回调
        [hud hideAnimated:YES];
        NSLog(@"%@",responseObject);
        finish(responseObject,nil);
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        //失败时的回调
        [hud hideAnimated:YES];
        finish(nil,error);
    }];
}


// 上传图片（多张）
+(void)uploadPhotoAndController:(UIViewController *)controller WithSize:(CGSize)size Image:(UIImage*)image AndFinish:(void (^)(NSDictionary *, NSError *))finish
{
    //加载提示菊花
    MBProgressHUD *hud;
    if(controller){
        hud = [MBProgressHUD showHUDAddedTo:controller.view animated:YES];
        hud.label.text = NSLocalizedString(@"加载中...", @"HUD loading title");
    }
    
    //1. 存放图片的服务器地址，这里我用的宏定义
    NSString * url = [NSString stringWithFormat:@"%@%@",Hx_Main_heard_API,IMAGE_UPLOAD_URL_API];
    
    //2. 发起网络请求
    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    manager.requestSerializer = [AFHTTPRequestSerializer serializer];
    manager.responseSerializer = [AFJSONResponseSerializer serializer];
    [manager POST:url parameters:nil constructingBodyWithBlock:^(id formData)
     {
         // 上传多张图片
         for(NSInteger i = 0; i < self.imageDataArray.count; i++)
         {
             //取出单张图片二进制数据
             NSData * imageData = self.imageDataArray[i];
             
             // 上传的参数名，在服务器端保存文件的文件夹名
             NSString * Name = [NSString stringWithFormat:@"%@%ld", Image_Name, i+1];
             // 上传filename
             NSString * fileName = [NSString stringWithFormat:@"%@.jpg", Name];
             
             [formData appendPartWithFileData:imageData name:Name fileName:fileName mimeType:@"image/jpeg"];
         }
     }
          success:^(AFHTTPRequestOperation *operation, id responseObject)
     {
         //上传成功时的回调
         [hud hideAnimated:YES];
         NSLog(@"%@",responseObject);
         finish(responseObject,nil);
     }
          failure:^(AFHTTPRequestOperation *operation, NSError *error)
     {
         //失败时的回调
         [hud hideAnimated:YES];
         finish(nil,error);
     }];
}