在objective-c中上传挑选的图像
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【中文标题】在objective-c中上传挑选的图像【英文标题】：upload picked image in objective-c 【发布时间】：2015-09-29 13:13:18 【问题描述】：我是 Objective-c 的新手。我需要在第一个函数中选择的图像在第二个函数中上传：
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
UIImage *chosenImage = info[UIImagePickerControllerEditedImage];
self.imageView.image = chosenImage;
[picker dismissViewControllerAnimated:YES completion:NULL];
- (IBAction)uploadPic:(UIButton *)sender
// COnvert Image to NSData
NSData *dataImage = UIImageJPEGRepresentation([UIImage imageNamed:@"yourImage"], 1.0f);
//added after editing
// set your URL Where to Upload Image
NSString *urlString = @"http://url";
// set your Image Name
NSString *filename = @"uploaded_file";
// Create 'POST' MutableRequest with Data and Other Image Attachment.
NSMutableURLRequest* request= [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:@"POST"];
NSString *boundary = @"---------------------------14737809831466499882746641449";
NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary];
[request addValue:contentType forHTTPHeaderField: @"Content-Type"];
NSMutableData *postbody = [NSMutableData data];
[postbody appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postbody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"userfile\"; filename=\"%@.jpg\"\r\n", filename] dataUsingEncoding:NSUTF8StringEncoding]];
[postbody appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[postbody appendData:[NSData dataWithData:dataImage]];
[postbody appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[request setHTTPBody:postbody];
// Get Response of Your Request
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *responseString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
NSLog(@"Response %@",responseString);
//end editing
在编辑 cmets 中添加的代码是我用来上传图像的代码
【问题讨论】：
【参考方案1】：您不应使用UIImageJPEGRepresentation 或UIImagePNGRepresentation。那些会丢失图像的元数据，使文件变大（或者如果您选择 JPEG 压缩因子使NSData 变小，它会降低图像质量）等等。
我建议您保存UIImagePickerControllerReferenceURL，然后，当用户选择保存图像时，您返回照片框架并检索图像的底层NSData。
所以，请务必导入 Photos 框架：
@import Photos;
另外，定义一个属性来捕获 URL：
@property (nonatomic, strong) NSURL *imageReferenceURL;
然后在获取图片的时候捕获这个URL：
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
UIImage *chosenImage = info[UIImagePickerControllerEditedImage];
self.imageView.image = chosenImage;
self.imageReferenceURL = info[UIImagePickerControllerReferenceURL];
[picker dismissViewControllerAnimated:YES completion:nil];
当你去上传图片时，从照片框架中检索原始资产的NSData：
- (IBAction)uploadPic:(UIButton *)sender
PHFetchResult *result = [PHAsset fetchAssetsWithALAssetURLs:@[self.imageReferenceURL] options:nil];
PHAsset *asset = [result firstObject];
if (asset)
PHImageManager *manager = [PHImageManager defaultManager];
[manager requestImageDataForAsset:asset options:nil resultHandler:^(NSData *imageData, NSString *dataUTI, UIImageOrientation orientation, NSDictionary *info)
// insert your code for uploading here, referencing the `imageData` here rather than `dataImage`.
// Or, I might recommend AFNetworking:
//
// For example, if your web service was expecting a `multipart/form-data` POST and was
// going to return a JSON response, you could do something like:
NSString *urlString = @"http://192.168.0.10/udazz/2.0/2.2/ios/1.0/actions.php?targ=user&subTarg=post&txtComment=123456&txtType=ff";
NSDictionary *parameters = @@"targ" : @"user",
@"subTarg" : @"post",
@"txtComment" : @"123456",
@"txtType" : @"ff";
NSURL *fileURL = info[@"PHImageFileURLKey"];
NSString *filename = [fileURL lastPathComponent];
NSString *mimeType = [self mimeTypeForPath:filename];
AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
// manager.responseSerializer = [AFHTTPResponseSerializer serializer]; // if response is string rather than JSON, uncomment this line
[manager POST:urlString parameters:parameters constructingBodyWithBlock:^(id<AFMultipartFormData> formData)
[formData appendPartWithFileData:imageData name:@"userfile" fileName:filename mimeType:mimeType];
success:^(NSURLSessionDataTask *task, id responseObject)
NSLog(@"responseObject = %@", responseObject);
failure:^(NSURLSessionDataTask *task, NSError *error)
NSLog(@"error = %@", error);
];
];
或者，如果您想使用自己的上传代码，只需将其调整为使用 NSURLSession（因为 NSURLConnection 现在已弃用，无论如何您都不应该进行同步网络请求）：
- (IBAction)uploadPic:(UIButton *)sender
PHFetchResult *result = [PHAsset fetchAssetsWithALAssetURLs:@[self.imageReferenceURL] options:nil];
PHAsset *asset = [result firstObject];
if (asset)
PHImageManager *manager = [PHImageManager defaultManager];
[manager requestImageDataForAsset:asset options:nil resultHandler:^(NSData *imageData, NSString *dataUTI, UIImageOrientation orientation, NSDictionary *info)
// upload the `imageData`
NSURL *fileURL = info[@"PHImageFileURLKey"];
NSString *filename = [fileURL lastPathComponent];
NSString *mimeType = [self mimeTypeForPath:filename];
NSString *urlString = @"http://192.168.0.10/udazz/2.0/2.2/ios/1.0/actions.php?targ=user&subTarg=post&txtComment=123456&txtType=ff";
NSMutableURLRequest* request= [NSMutableURLRequest requestWithURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:@"POST"];
NSString *boundary = @"---------------------------14737809831466499882746641449";
NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary];
[request addValue:contentType forHTTPHeaderField: @"Content-Type"];
NSMutableData *postbody = [NSMutableData data];
[postbody appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postbody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"userfile\"; filename=\"%@\"\r\n", filename] dataUsingEncoding:NSUTF8StringEncoding]];
[postbody appendData:[[NSString stringWithFormat:@"Content-Type: %@\r\n\r\n", mimeType] dataUsingEncoding:NSUTF8StringEncoding]];
[postbody appendData:imageData];
[postbody appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
NSURLSessionTask *task = [[NSURLSession sharedSession] uploadTaskWithRequest:request fromData:postbody completionHandler:^(NSData *data, NSURLResponse *response, NSError *error)
NSString *responseString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"Response %@",responseString);
];
[task resume];
];
顺便说一下，我以编程方式确定 mime 类型的例程（因为你真的不能只假设图像是 JPEG；它也可能是 PNG 和其他类型）如下：
- (NSString *)mimeTypeForPath:(NSString *)path
// get a mime type for an extension using MobileCoreServices.framework
CFStringRef extension = (__bridge CFStringRef)[path pathExtension];
CFStringRef UTI = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, extension, NULL);
assert(UTI != NULL);
NSString *mimetype = CFBridgingRelease(UTTypeCopyPreferredTagWithClass(UTI, kUTTagClassMIMEType));
assert(mimetype != NULL);
CFRelease(UTI);
return mimetype;
如果您需要支持早于 Photos 框架的 iOS 版本，请使用ALAssetsLibrary 获取NSData。如果您需要如何执行此操作的示例（仅当您需要支持 8.0 之前的 iOS 版本时），请告诉我。
【讨论】：
我是 Objective-c 的新手，老实说，我不知道该把代码放在哪里。 @MarianoPelizzari - 不用担心。我扩展了我的代码 sn-p 以使其更清晰。 谢谢。现在，我的代码的哪一部分进入了//upload the imageData here？
@MarianoPelizzari - 抱歉，我假设您已经有了上传图片的代码。不幸的是，答案完全取决于您的 Web 服务需要如何形成图像上传请求。许多 Web 服务会期望 Content-Type 和 multipart/form-data 的 POST 请求（并且像 AFNetworking 这样的工具大大简化了创建这种复杂类型请求的过程），但是您需要确认，因为有过多的替代品。您还需要 URL、字段名称等详细信息。
我在我的问题中添加了代码，它位于//added after editing 和//end editing 之间。正如代码所示，我需要上传和图像。你能告诉我我是否可以在你的代码中使用部分代码（或全部），你说//upload the imageData here【参考方案2】：
您正在将选取的图像分配给您的 imageView。因此，您可以使用 UIImageView 的 image 属性访问它。
你可以像这样访问：
- (IBAction)uploadPic:(UIButton *)sender
NSData *dataImage = UIImageJPEGRepresentation(self.imageView.image, 1.0f);
// Do your stuff here
【讨论】：
【参考方案3】：我已经在我的演示项目中完成了您的要求。我使用 UIIMagePicker 委托函数选择了图像
@interface ViewController ()
UIImage *chooseImage;
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
NSDate *time = [NSDate date];
NSDateFormatter* df = [NSDateFormatter new];
[df setDateFormat:@"ddMMyyyy-hhmmss"];
NSString *timeString = [df stringFromDate:time];
NSString *fileName = [NSString stringWithFormat:@"%@", timeString];
chooseImage = info[UIImagePickerControllerEditedImage];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
documentsDirectoryPath = [paths objectAtIndex:0];
NSLog(@"View Controller Path:%@",documentsDirectoryPath);
savedImagePath = [documentsDirectoryPath
stringByAppendingPathComponent:[NSString stringWithFormat: @"%@-%d.png", fileName, num]];
num += 1;
NSData *imageData = UIImagePNGRepresentation(chooseImage);
[imageData writeToFile:savedImagePath atomically:NO];
[picker dismissViewControllerAnimated:YES completion:NULL];
[self displayImage];
-(void)displayImage
self.imageView.image = chooseImage;
从那个方法中我调用了另一个函数->displayImage，我用它来在 UIImageView 中显示图像。下面是代码。
【讨论】：
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