关于使用ASIHTTPRequest进行断点续传

最近项目中用到了ASI的断点续传，把其中遇到的问题和解决方法与大家分享

NSString *bookPath = [RBUtilsObject filePathString:s9id];    ASIHTTPRequest *bookDownloadRequest = [[ASIHTTPRequest alloc]initWithURL:requestURL];    bookDownloadRequest.shouldContinueWhenAppEntersBackground = YES;    [bookDownloadRequest setDownloadDestinationPath:bookPath];    NSString *tmpbookPath = [RBUtilsObject tmpfilePathString:s9id];    [bookDownloadRequest setTemporaryFileDownloadPath:tmpbookPath];    [bookDownloadRequest setAllowResumeForFileDownloads:YES];    bookDownloadRequest.allowCompressedResponse = NO;           __block NSString *currentDownloadBookID = s9id;    __block BOOL isAddToShelf = NO;    [bookDownloadRequest setBytesReceivedBlock:^(unsigned long long size, unsigned long long total) {        if ( total !=0) {            if (isAddToShelf == NO) {                isAddToShelf = YES;                [[NSNotificationCenter defaultCenter]postNotificationName:@(kIsAddToShelf) object:nil userInfo:[NSDictionary dictionaryWithObjectsAndKeys:currentDownloadBookID,@(kCurrentDownloadBookID), nil]];//s9id            }            float progressAmount = (float)((size*1.0)/(total*1.0));                       NSLog(@"downloadPercent=%f  s9id= %@",progressAmount,currentDownloadBookID);            //这里的size其实是request接收到的数据的回调block，并不是当前全部已下载的数据，因此在这样不能正确显示下载进度           [[NSNotificationCenter defaultCenter]postNotificationName:currentDownloadBookID object:@(progressAmount)];                                }    }];

解决方案如下：找到ASIHTTPRequest的.m文件

- (void)updateDownloadProgress{// We won't update download progress until we've examined the headers, since we might need to authenticateif (![self responseHeaders] || [self needsRedirect] || !([self contentLength] || [self complete])) {return;}unsigned long long bytesReadSoFar = [self totalBytesRead]+[self partialDownloadSize];unsigned long long value = 0;if ([self showAccurateProgress] && [self contentLength]) {value = bytesReadSoFar-[self lastBytesRead];if (value == 0) {return;}} else {value = 1;[self setUpdatedProgress:YES];}if (!value) {return;}[ASIHTTPRequest performSelector:@selector(request:didReceiveBytes:) onTarget:&queue withObject:self amount:&value callerToRetain:self];[ASIHTTPRequest performSelector:@selector(request:didReceiveBytes:) onTarget:&downloadProgressDelegate withObject:self amount:&value callerToRetain:self];[ASIHTTPRequest updateProgressIndicator:&downloadProgressDelegate withProgress:[self totalBytesRead]+[self partialDownloadSize] ofTotal:[self contentLength]+[self partialDownloadSize]];#if NS_BLOCKS_AVAILABLE    if (bytesReceivedBlock) {unsigned long long totalSize = [self contentLength] + [self partialDownloadSize];//[self performBlockOnMainThread:^{ if (bytesReceivedBlock) { bytesReceivedBlock(value, totalSize); }}];此处修改为即可将下载进度正确返回        [self performBlockOnMainThread:^{            if (bytesReceivedBlock) {                bytesReceivedBlock(([self totalBytesRead] + [self partialDownloadSize]),totalSize);            }        }];    }#endif[self setLastBytesRead:bytesReadSoFar];}