iOS 一次上传多张图片, 并返回进度值

/**
*  上传带图片的内容，允许多张图片上传（URL）POST
*
*  @param url                 网络请求地址
*  @param images              要上传的图片数组（注意数组内容需是图片）
*  @param parameter           图片数组对应的参数  (注意多张图片,每张的图片名应该不同)
*  @param parameters          其他参数字典
*  @param ratio               图片的压缩比例（0.0~1.0之间）
*  @param succeedBlock        成功的回调
*  @param failedBlock         失败的回调
*  @param uploadProgressBlock 上传进度的回调
*/
+(void)startMultiPartUploadTaskWithURL:(NSString *)url
                           imagesArray:(NSArray *)images
                     parameterOfimages:(NSString *)parameter
                        parametersDict:(NSDictionary *)parameters
                      compressionRatio:(float)ratio
                          succeedBlock:(void(^)(id operation, id responseObject))succeedBlock
                           failedBlock:(void(^)(id operation, NSError *error))failedBlock
                   uploadProgressBlock:(void(^)(float uploadPercent,long long totalBytesWritten,long long totalBytesExpectedToWrite))uploadProgressBlock;

实现：
+(void)startMultiPartUploadTaskWithURL:(NSString *)url
                           imagesArray:(NSArray *)images
                     parameterOfimages:(NSString *)parameter
                        parametersDict:(NSDictionary *)parameters
                      compressionRatio:(float)ratio
                          succeedBlock:(void (^)(id, id))succeedBlock
                           failedBlock:(void (^)(id, NSError *))failedBlock
                   uploadProgressBlock:(void (^)(float, long long, long long))uploadProgressBlock{
    
    if (images.count == 0) {
        NSLog(@"上传内容没有包含图片");
        return;
    }
    for (int i = 0; i < images.count; i++) {
        if (![images isKindOfClass:[UIImage class]]) {
            NSLog(@"images中第%d个元素不是UIImage对象",i+1);
            return;
        }
    }
    
    AFHTTPRequestOperation *operation = [[self sharedOperation].operationManager POST:url parameters:parameters constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
        
        int i = 0;
        //根据当前系统时间生成图片名称
        NSDate *date = [NSDate date];
        NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
        [formatter setDateFormat:@"yyyy年MM月dd日"];
        NSString *dateString = [formatter stringFromDate:date];
        
        for (UIImage *image in images) {
            NSString *fileName = [NSString stringWithFormat:@"%@%d.png",dateString,i];
            NSData *imageData;
            if (ratio > 0.0f && ratio < 1.0f) {
                 imageData = UIImageJPEGRepresentation(image, ratio);
            }else{
                imageData = UIImageJPEGRepresentation(image, 1.0f);
            }
           
            [formData appendPartWithFileData:imageData name:parameter fileName:fileName mimeType:@"image/jpg/png/jpeg"];
        }
    
        
    } success:^(AFHTTPRequestOperation *operation, id responseObject) {
        succeedBlock(operation,responseObject);
        
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"%@",error);
        failedBlock(operation,error);
        
    }];
    
    [operation setUploadProgressBlock:^(NSUInteger bytesWritten, long long totalBytesWritten, long long totalBytesExpectedToWrite) {
        CGFloat percent = totalBytesWritten * 1.0 / totalBytesExpectedToWrite;
        uploadProgressBlock(percent,totalBytesWritten,totalBytesExpectedToWrite);
    }];
    
}