iOS 两种方式上传图片

1.用base64把图片转化为字符串作为关键字上传
主要是获取到图片，然后转化为字符串上传

 //先判断图片是否存在
    if (image != nil) {
        //图片显示在界面上
//        [changeImg setBackgroundImage:image forState:UIControlStateNormal];
        
        //以下是保存文件到沙盒路径下
        //把图片转成NSData类型的数据来保存文件
        NSData *data;
        //判断图片是不是png格式的文件
        if (UIImagePNGRepresentation(image)) {
            //返回为png图像。
            data = UIImagePNGRepresentation(image);
        }else {
            //返回为JPEG图像。
            data = UIImageJPEGRepresentation(image, 1.0);
        }
        NSString *imageStr = [data base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}

2.用AFNetworking上传

    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    manager.responseSerializer.acceptableContentTypes = [NSSet setWithObject:@"text/html"];
    [manager POST:urlStr parameters:dic constructingBodyWithBlock:^(id<AFMultipartFormData>  _Nonnull formData) {
//先判断图片是否存在
        if (_SelectImage == nil) {
            return ;
        } else {
            UIImage *iamge = _SelectImage;
            NSData *data = UIImagePNGRepresentation(iamge);
            [formData appendPartWithFileData:data name:@"file" fileName:@"file.png" mimeType:@"image/png"];
        }
    } progress:nil success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
        NSLog(@"%@", responseObject);
        NSDictionary *dic = responseObject;
        if ([dic[@"Code"] isEqualToString:@"000000"]) {
            [hud hideAnimated:YES];
            [Tool showHUDWithString:@"保存资料成功" AndView:self.view];
        } else {
            [hud hideAnimated:YES];
            [Tool showHUDWithString:dic[@"Msg"] AndView:self.view];
        }
    } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
        [hud hideAnimated:YES];
        [Tool showHUDWithString:@"网络君跑路了。。。" AndView:self.view];
        NSLog(@"%@",error);
    }];