使用NSURL访问保存的照片中的图像并上传到S3的正确方式？

Question

我正在使用此代码将图像上传到S3

    AWSS3TransferManager *transferManager = [AWSS3TransferManager defaultS3TransferManager];
    AWSS3TransferManagerUploadRequest *uploadRequest = [AWSS3TransferManagerUploadRequest new];
    uploadRequest.bucket = @"my-photo-bucket";
    uploadRequest.key = @"test_upload";
    long long fileSize = [[[NSFileManager defaultManager] attributesOfItemAtPath:self.imageUrl.path error:nil][NSFileSize] longLongValue];
    uploadRequest.contentLength = [NSNumber numberWithUnsignedLongLong:fileSize];
    uploadRequest.body = self.imageUrl.absoluteURL;

    [[transferManager upload:uploadRequest] continueWithBlock:^id(BFTask *task) {
        NSLog(@"%@", task.error);
        return nil;
    }];

当我尝试上传文件时，它失败了，因为URL似乎没有指向我的应用程序可以访问的内容：

2014-09-08 11:57:47.014 myapp[1551:60b] Url: assets-library://asset/asset.JPG?id=721E68A8-DF94-4404-A37D-FECDCDC60C1D&ext=JPG, File Size: (null) 
2014-09-08 11:57:47.025 myapp[1551:60b] Error Domain=NSCocoaErrorDomain Code=260 "The operation couldn’t be completed. (Cocoa error 260.)" UserInfo=0x17827c2c0 {NSFilePath=/asset.JPG, NSUnderlyingError=0x178256e60 "The operation couldn’t be completed. No such file or directory"} 

对我来说，这似乎是一个有效的URL。我做错了什么？

Answer 1

看起来AWS-SDK-IOS项目目前不支持这一点。请参阅github bug report。

他们建议的解决办法是在开始上传之前将资产复制到您的应用程序目录。

Answer 2

这与我的工作完美，检查它。

//Configuration 
AWSCognitoCredentialsProvider *credentialsProvider = [[AWSCognitoCredentialsProvider alloc]
                                                      initWithRegionType:AWSRegionEUWest1
                                                      identityPoolId:CognitoIdentityPoolId];


AWSServiceConfiguration *configuration = [[AWSServiceConfiguration alloc] initWithRegion:DefaultServiceRegionType
                                                                     credentialsProvider:credentialsProvider];

[AWSServiceManager defaultServiceManager].defaultServiceConfiguration = configuration;

//Create temporary directory 
NSError *error = nil;
if (![[NSFileManager defaultManager] createDirectoryAtPath:[NSTemporaryDirectory() stringByAppendingPathComponent:@"upload"]
                               withIntermediateDirectories:YES
                                                attributes:nil
                                                     error:&error]) {
    NSLog(@"reading 'upload' directory failed: [%@]", error);
}

//write the image to the created directory 
UIImage *image =  [your image]; //Check below how do I get it 

NSString *fileName = [[[NSProcessInfo processInfo] globallyUniqueString] stringByAppendingString:@".jpg"];

NSString *filePath = [[NSTemporaryDirectory() stringByAppendingPathComponent:@"upload"] stringByAppendingPathComponent:fileName];

NSData * imageData = UIImagePNGRepresentation(image);
[imageData writeToFile:filePath atomically:YES];

//Create upload request 
AWSS3TransferManagerUploadRequest *uploadRequest = [AWSS3TransferManagerUploadRequest new];
uploadRequest.body = [NSURL fileURLWithPath:filePath];

uploadRequest.key = [NSString stringWithFormat:@"%@", fileName]; //You can add you custom path here. Example: [NSString stringWithFormat:@"public/myImages/%@", fileName];


AWSS3TransferManager *transferManager = [AWSS3TransferManager defaultS3TransferManager];

uploadRequest.bucket = S3BucketName;
uploadRequest.body = [NSURL fileURLWithPath:filePath];

[[transferManager upload:uploadRequest] continueWithExecutor:[BFExecutor mainThreadExecutor]
                                                       withBlock:^id(BFTask *task) {
                                                           if (task.error) {
                                                               if ([task.error.domain isEqualToString:AWSS3TransferManagerErrorDomain]) {
                                                                   switch (task.error.code) {
                                                                       case AWSS3TransferManagerErrorCancelled:
                                                                       case AWSS3TransferManagerErrorPaused:
                                                                           break;

                                                                       default:
                                                                           NSLog(@"Error: %@", task.error);
                                                                           break;
                                                                   }
                                                               } else {
                                                                   // Unknown error.
                                                                   NSLog(@"Error: %@", task.error);
                                                               }
                                                           }

                                                           if (task.result) {

                                                               // The file uploaded successfully.


                                                           }
                                                           return nil;
                                                       }];
}

下面是如何使用NSURL从保存的照片中获取图像：

NSURL* imageURL = [NSURL URLWithString:urlString];

ALAssetsLibrary * _library = [[ALAssetsLibrary alloc] init];

[_library assetForURL:imageURL resultBlock:^(ALAsset *asset) {


    UIImage  *bigImage = [UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage] scale:0.5 orientation:UIImageOrientationUp];


    }
             failureBlock:^(NSError *error)
     {
         // error handling
         NSLog(@"failure-----");
     }];