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我有一个包含三列“缩略图”、“文件名”和“日期修改”的 NSTableview。文件名列和修改日期列由 S3ListObjectResponse 的输出填充。而“缩略图”列图像是从机器的本地目录加载的。如果文件丢失，我会从 S3 云下载。问题是如何将数据插入到 NSArrayController 如果文件丢失并且我留下了一个空单元格作为缩略图？这是我现在的工作：

- (IBAction)checkCloud:(id)sender {
AmazonS3Client *s3 = [AmazonClientManager s3];

S3ListObjectsRequest* listObjectsRequest = [[S3ListObjectsRequest alloc] initWithName:@"hello-testing"];



NSRange range = NSMakeRange(0, [[_fileListAC arrangedObjects] count]);
[_fileListAC removeObjectsAtArrangedObjectIndexes:[NSIndexSet indexSetWithIndexesInRange:range]];

@try {


    S3ListObjectsResponse* response = [s3 listObjects:listObjectsRequest];

    NSMutableArray* objectSummaries = response.listObjectsResult.objectSummaries;

    //looping through the objSummary and add into the NSArrayController
    for ( S3ObjectSummary* objSummary in objectSummaries ) {

        NSImage *thumbnail = [[NSImage alloc] init ];


        NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];


        [dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"];

        NSDate *s3date = [dateFormatter dateFromString:[objSummary lastModified]];


        NSArray *fileName =  [[objSummary key] componentsSeparatedByString:@"/"];
        if([[fileName objectAtIndex:0] localizedCaseInsensitiveCompare:@"Range"] == NSOrderedSame) {
            NSLog(@"file name %@ ",[fileName objectAtIndex:1]);

           // Check for files in side the bucket's folders 
           if([[fileName objectAtIndex:1] length]){

                NSString *thumbnailFile = [[fileName objectAtIndex:1] stringByAppendingString:@"_thumb.png"];


                BOOL isDir;

                NSFileManager *fileManager = [NSFileManager defaultManager];

                NSString *filePathPart1 = [@"/Users/" stringByAppendingString:[[NSHost currentHost] localizedName]];

                NSString *filePath = [[[[ filePathPart1 stringByAppendingString:@"/Documents/Test/" ] stringByAppendingString:@"Range" ] stringByAppendingString:@"/Thumbnail/"] stringByAppendingString:thumbnailFile];


               // If file exists then add into the thumbnail column
               if([fileManager fileExistsAtPath:filePath isDirectory:&isDir]){

                    thumbnail = [[NSImage alloc] initWithContentsOfFile:filePath];



                }else{

                     NSLog(@"file %@ not found",thumbnailFile);


                    //Downloading from the S3 Cloud Asynchronously

                    doneDownload = NO;
                    AmazonS3Client *s3 = [AmazonClientManager s3];
                    S3GetObjectRequest *gor = nil;
                    @try {

                        gor = [[S3GetObjectRequest alloc] initWithKey:[[@"Range/Thumbnail/"  stringByAppendingString:[fileName objectAtIndex:1]] stringByAppendingString: @"_thumb"] withBucket:@"thumbnail-pic" ];
                        gor.delegate = self;
                        [s3 getObject:gor];
                    }
                    @catch (AmazonClientException *exception) {
                        doneDownload = YES;
                    }

                    do {
                        [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
                    } while (!doneDownload);
                    gor.delegate = nil;

                }

            }else{
                //If its the actual bucket folder and not file then load a default image 
                thumbnail = [NSImage imageNamed:@"Range.png"];
            }

        }

           [_fileListAC addObject:[NSMutableDictionary  dictionaryWithObjectsAndKeys:thumbnail,@"thumbnail", [objSummary key],@"Files",s3Date,@"Date Modified", nil]];





    }
}
@catch (NSException *exception) {
    NSLog(@"Cannot list S3 %@",exception);
}

//Display the table on loading the NSArrayController
[_cloudFileList makeKeyAndOrderFront:nil]; 

}

我检查了委托方法

 -(void)request:(AmazonServiceRequest *)request didCompleteWithResponse:(AmazonServiceResponse *)response{
NSData *imageData = [response body];
_coreDataImageView.image = [[NSImage alloc] initWithData:imageData];
doneDownload = YES;
}

coredataimageview 是一个测试图像。图像已下载，但我想将其添加回阵列控制器。问题是，如果本地目录中缺少 3 个文件，并且我无法将该文件名和日期修改值插入到数组控制器中，该怎么办。对此有什么帮助吗？

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1 回答 1

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如果您实现了一个委托对象（而不是使用 self），您可以将这些对象存储在一个数组中并稍后引用它们。委托对象可以跟踪您感兴趣的其他元数据，并可用于构建您的表格视图。

于 2013-01-07T17:21:14.357 回答