AFNetworking 3.0 setImageWithURLRequest download progress

问题

Does anyone have a nice working solution for getting the download progress when using the UIImageView+AFNetworking category and AFNetworking 3.0.

This category, which I did use for versions up till 3.0 has stopped working now.

Here is my own experimental version which sadly, for the moment, crashes randomly.

回答1:

Here is the modified version of AFNetworking 3.0 in which you can show a progress while loading image from server using UIImageView+AFNetworking category.

https://github.com/rushisangani/AFNetworking

Please replace following files with original AFNetworking files.

UIImageView+AFNetworking.h,
UIImageView+AFNetworking.m,

UIImage+ImageDownloader.h,
UIImage+ImageDownloader.m

NOTE: If you update your pod then this will be removed.

回答2:

If you look at AFImageDownloader this, it is used by the UIImageView category to download images. In this class you

- (nullable AFImageDownloadReceipt *)downloadImageForURLRequest:  (NSURLRequest *)request
                                                    success:(nullable void (^)(NSURLRequest *request, NSHTTPURLResponse  * _Nullable response, UIImage *responseObject))success
                                                    failure:(nullable void (^)(NSURLRequest *request, NSHTTPURLResponse * _Nullable response, NSError *error))failure;

It returns a receipt which has a NSURLSessionDataTask *task property. NSURLSessionDataTask has different properties of how bytes download, expected bytes to receive etc. Perhaps you can use this and achieve your task.

回答3:

You can achieve this by adding few lines in UIImageView+AFNetworking.h

Place this code at top of the file under the import statement

static void * AFTaskCountOfBytesReceivedContext = &AFTaskCountOfBytesReceivedContext;

And you need to register the observer to track the bytes received by adding below line under the function setImageWithURLRequest at the position

if (cachedImage) {
    // AFNetworking default code
}
else{
    // AFNetworking default code
    // Our new lines to track the download
    [self.af_activeImageDownloadReceipt.task addObserver:self forKeyPath:@"state" options:(NSKeyValueObservingOptions)0 context:AFTaskCountOfBytesReceivedContext];
    [self.af_activeImageDownloadReceipt.task addObserver:self forKeyPath:@"countOfBytesReceived" options:(NSKeyValueObservingOptions)0 context:AFTaskCountOfBytesReceivedContext];
}

Add this new function at end.

#pragma mark - NSKeyValueObserving

- (void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object
                        change:(__unused NSDictionary *)change
                       context:(void *)context
{
    if (context == AFTaskCountOfBytesReceivedContext) {

        if ([keyPath isEqualToString:NSStringFromSelector(@selector(countOfBytesReceived))]) {
            if ([object countOfBytesExpectedToReceive] > 0) {
                dispatch_async(dispatch_get_main_queue(), ^{
                    //You can do your stuff at here like show progress
                    NSLog(@"Progress : %f",[object countOfBytesReceived] / ([object countOfBytesExpectedToReceive] * 1.0f));

                });
            }
        }

        if ([keyPath isEqualToString:NSStringFromSelector(@selector(state))]) {
            if ([(NSURLSessionTask *)object state] == NSURLSessionTaskStateCompleted) {
                @try {
                    [object removeObserver:self forKeyPath:NSStringFromSelector(@selector(state))];
                    NSLog(@"Image Download Complete");
                    if (context == AFTaskCountOfBytesReceivedContext) {
                        [object removeObserver:self forKeyPath:NSStringFromSelector(@selector(countOfBytesReceived))];
                    }
                }
                @catch (NSException * __unused exception) {}
            }
        }
    }
}

来源：https://stackoverflow.com/questions/34744024/afnetworking-3-0-setimagewithurlrequest-download-progress

标签

ios

uiimageview

afnetworking

progress

afnetworking-3