ios - UIProgressView 不更新状态

Question

我的新应用程序有小问题。一开始我以为这只是线程的问题，但现在我觉得我必须重写一半的代码来修复它。在此之前，也许你会帮助我:)

现在我正在编写将从服务器下载东西的应用程序。我们有两个对象:MainViewController UI 在哪里和 DataManager我在哪里处理文件。一开始，我正在检查服务器上的更改 DataManager :

[NSURLConnection sendAsynchronousRequest:[[NSURLRequest alloc] initWithURL:dataURL] queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
            if (error) {
                //Data was not downloaded
            } else {
                //Downloading data base
                [[NSOperationQueue mainQueue] addOperationWithBlock:^{

                    if (dataFileExists) { //compare and save downloaded data base: localDataArray i downloadedDataArray

                        if ([localDataArray isEqual:DownloadedDataArray]) {
                            [self.delegate dataWasLoaded];
                        }
                    } else {

                        [self synchronizeAllTheFiles]; //Data base sync

                        [self.delegate dataWasLoaded];
                    }

                }];
            }
        }];

接下来，当我知道服务器上存在差异时，我会同步所有数据。有两种委托(delegate)方法: beginUploadDataBaseWithNumberOfObjectsToDownload和 fileWasDownloaded .

首先检查要下载多少文件。

其次将+1添加到下载的文件。此方法的委托(delegate)在 MainViewController .

- (void)synchronizeAllTheFiles {
    NSMutableArray *arrayWithLinksToDownload = [[NSMutableArray alloc] init];                               //Table of links

    [self.delegate beginUploadDataBaseWithNumberOfObjectsToDownload:[arrayWithLinksToDownload count]]; //How many things are to download

    for (int d = 0; d < [arrayWithLinksToDownload count]; d++) { //Runloop to download links
                                          //Downloading Data

        if (urlData) {                                                                                      //If data was downloaded

            [urlData writeToFile:filePath atomically:YES];                                                  //Save on device

            [self.delegate fileWasDownloaded]; //MainViewController Add next downloaded file
        }
    }
}

MainViewController 中有委托(delegate)方法:

- (void)beginUploadDataBaseWithNumberOfObjectsToDownload:(int)numberToDownload {
    IfDownloadingData = YES;
    ItemsToDownloadCount = numberToDownload;
    ItemsDownloadedCount = 0;
}

- (void)fileWasDownloaded {
    ItemsDownloadedCount++;
    float progress = (float)ItemsDownloadedCount/(float)ItemsToDownloadCount;
    NSLog(@"%ld/%li - %f", (long)ItemsDownloadedCount, (long)ItemsToDownloadCount, progress);
    [self.LoadingProgressView setProgress:progress animated:YES];
}

问题是 ProgressView 不想更新他们的状态。我正在尝试添加调度 block ，但如果 ProgressView 在主线程中，屏幕上根本不会改变。我正在尝试通过 NSTimer 来管理它和调度书籍，但不幸的是问题存在。

我会很高兴得到任何帮助:)

Answer 1

您只需将更新 GUI 代码放在主线程中，无需其他任何内容。

 dispatch_async(dispatch_get_main_queue(), ^{
     [self.LoadingProgressView setProgress:progress animated:YES];
 });

然后乘坐 addOperationWithBlock线:

[NSURLConnection sendAsynchronousRequest:[[NSURLRequest alloc] initWithURL:dataURL] queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
        if (error) {
            //Data was not downloaded
        } else {
            // **Remove this line**
            // [[NSOperationQueue mainQueue] addOperationWithBlock:^{

                if (dataFileExists) { //compare and save downloaded data base: localDataArray i downloadedDataArray

                    if ([localDataArray isEqual:DownloadedDataArray]) {
                        [self.delegate dataWasLoaded];
                    }
                } else {

                    [self synchronizeAllTheFiles]; //Data base sync

                    [self.delegate dataWasLoaded];
                }
            // **Remove this line**
            // }];
        }
    }];

而且，我看不到你从哪里得到 urlData .但无论如何，这个循环不应该在主线程中，因为它会使主线程保持忙碌，因此无法更新您的 GUI。

for (int d = 0; d < [arrayWithLinksToDownload count]; d++) { //Runloop to download links

        //Downloading Data

        if (urlData) {                                                                                     
            //If data was downloaded
            [urlData writeToFile:filePath atomically:YES];                                                 
            //Save on device
            [self.delegate fileWasDownloaded]; //MainViewController Add next downloaded file
        }