从ios上载图像时出现错误400

我对ios非常陌生。我必须从ios应用程序上传一个图像到rest服务器。我已经提到过了。但每次响应都是400，这是来自客户端的错误请求。我正在从设备文档目录中拍摄图像。是否有人可以发布图像上载的确切代码。请参考我使用的代码。我不确定使用什么作为文件名，因为我正在从文档目录下载图像

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
        [request setHTTPMethod:@"POST"];
        [request setURL:[NSURL URLWithString:@"urltoupload"]];

        NSString *stringBoundary = @"----1010101010";
        NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",stringBoundary];
        [request setValue:contentType forHTTPHeaderField:@"Content-Type"];


        NSMutableData *body = [NSMutableData data];
        [body appendData:[[NSString stringWithFormat:@"--%@\r\n", stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[[NSString stringWithFormat:@"Content-Disposition:attachment; name=\"userfile\"; filename=\"image.png\"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[@"Content-Type: application/octet-stream\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];

        [body appendData:pngImageData];
        [body appendData:[[NSString stringWithFormat:@"\r\n"]   dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[[NSString stringWithFormat:@"--%@--\r\n", stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]];
        [request setHTTPBody:body];


NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
      NSString *str = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
       NSLog(@"return Data ---- %@", str);

试试这个：

// create request
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];                                    
[request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
[request setHTTPShouldHandleCookies:NO];
[request setTimeoutInterval:30];
[request setHTTPMethod:@"POST"];

// set Content-Type in HTTP header
NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
[request setValue:contentType forHTTPHeaderField: @"Content-Type"];

// post body
NSMutableData *body = [NSMutableData data];

// add params (all params are strings)
for (NSString *param in _params) {
    [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n", param] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithFormat:@"%@\r\n", [_params objectForKey:param]] dataUsingEncoding:NSUTF8StringEncoding]];
}

// add image data
NSData *imageData = UIImageJPEGRepresentation(imageToPost, 1.0);
if (imageData) {
    [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"image.jpg\"\r\n", FileParamConstant] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithString:@"Content-Type: image/jpeg\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:imageData];
    [body appendData:[[NSString stringWithFormat:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
}

[body appendData:[[NSString stringWithFormat:@"--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];

// setting the body of the post to the reqeust
[request setHTTPBody:body];

// set URL
[request setURL:requestURL];

---

希望能有帮助

首先将UIImage转换为NSData，如下所示

UIImage *image = [UIImage imageNamed:@"example.png"];
NSData *data = UIImagePNGRepresentation(image);

或

然后形成您的请求字符串

NSURL *url = [NSURL URLWithString:serverURL];

//Time out interval need to be tuned
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url
                                                       cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
[request setHTTPMethod:@"POST"];

[request setHTTPBody: [requestString dataUsingEncoding:NSUTF8StringEncoding]];
[NSURLConnection sendAsynchronousRequest:request queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error){
    if (!data)
    {
        NSLog(@"Error downloading data: %@", error);
        return;
    }
    NSError *error1;
    NSDictionary *theDict = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error1];
    DLog(@"Data received :%@", theDict);

}];

---

你有没有研究过网络？他们有很多方法可以简化不同的网络请求，我从来没有遇到过下载或上传图像的问题。值得研究。

NSURL *url = [NSURL URLWithString:serverURL];

//Time out interval need to be tuned
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url
                                                       cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
[request setHTTPMethod:@"POST"];

[request setHTTPBody: [requestString dataUsingEncoding:NSUTF8StringEncoding]];
[NSURLConnection sendAsynchronousRequest:request queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error){
    if (!data)
    {
        NSLog(@"Error downloading data: %@", error);
        return;
    }
    NSError *error1;
    NSDictionary *theDict = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error1];
    DLog(@"Data received :%@", theDict);

}];