我的应用程序正在使用 NSURLConnection 从 Internet 下载文件。
正在发生两个问题：
1) [connection didReceiveData] 永远不会被调用
2）当调用[connection didFinishDownloading]时，我的self.currentData为空
我究竟做错了什么？
我的标题如下所示：
@interface DIFileDownloader : NSObject <NSURLConnectionDelegate> {
NSMutableData *currentData;
}
@property (nonatomic, assign) id <DIFileDownloaderDelegate> delegate;
@property (nonatomic, retain) NSMutableArray *supportedFormats;
@property (nonatomic, retain) NSMutableData *currentData;
@property (nonatomic, retain) NSURLConnection *downloadAgent;
@property (nonatomic) long long expectedContentSize;
@property (nonatomic) float currentDownloadProgress;
@property (nonatomic, getter = isRunning) BOOL running;
-(instancetype)initWithSupportedFormats:(NSArray *)extensions;
-(void)downloadFileAtURL:(NSURL *)url;
-(NSString *)documentsDirectoryPath;
@end
还有我的实现文件：
-(instancetype)initWithSupportedFormats:(NSArray *)extensions {
self.supportedFormats = [[NSMutableArray alloc] initWithArray:extensions];
self.running = NO;
}
-(void)downloadFileAtURL:(NSURL *)url {
NSString *fileExtension = [url pathExtension];
if ([self.supportedFormats containsObject:fileExtension]) {
self.downloadAgent = [[NSURLConnection alloc] initWithRequest:[NSURLRequest requestWithURL:url] delegate:self];
[self.downloadAgent start];
NSLog(@"Beginning download at URL:%@", url.absoluteString);
}
else {
}
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
NSLog(@"Connection recieved response with size: %f", (float)[response expectedContentLength]);
self.expectedContentSize = (float)[response expectedContentLength];
self.running = YES;
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse*)response;
NSLog(@"%i", [httpResponse statusCode]);
/*
if ([httpResponse statusCode] >= 200 && [httpResponse statusCode] <= 299) {
}
*/
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
NSLog(@"%f", (float)[data length]);
[currentData appendData:data];
self.currentDownloadProgress = ((float)[data length] / self.currentDownloadProgress);
NSLog(@"Connection recieved data. New progress is: %f", self.currentDownloadProgress);
if ([self.delegate respondsToSelector:@selector(downloader:progressChanged:)]) {
[self.delegate downloader:self progressChanged:self.currentDownloadProgress];
}
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
NSLog(@"Connection failed");
if ([self.delegate respondsToSelector:@selector(downloader:failedToDownloadFileAtURL:reason:)]) {
[self.delegate downloader:self failedToDownloadFileAtURL:connection.originalRequest.URL reason:error];
}
}
-(void)connectionDidFinishDownloading:(NSURLConnection *)connection destinationURL:(NSURL *)destinationURL {
NSLog(@"Connection finished downloading with size: %f", (float)[currentData length]);
self.running = NO;
NSString *filename = [destinationURL.absoluteString lastPathComponent];
NSString *docPath = [self documentsDirectoryPath];
NSString *pathToDownloadTo = [NSString stringWithFormat:@"%@/%@", docPath, filename];
NSError *error = nil;
[currentData writeToFile:pathToDownloadTo options:NSDataWritingAtomic error:&error];
if (error != nil) {
NSLog(@"DIFileDownloader: Failed to save the file because: %@", [error description]);
if ([self.delegate respondsToSelector:@selector(downloader:failedToDownloadFileAtURL:reason:)]) {
[self.delegate downloader:self failedToDownloadFileAtURL:connection.originalRequest.URL reason:error];
}
}
else {
if ([self.delegate respondsToSelector:@selector(downloader:finishedDownloadingFileNamed:atPath:)]) {
[self.delegate downloader:self finishedDownloadingFileNamed:filename atPath:pathToDownloadTo];
}
}
}
- (NSString *)documentsDirectoryPath {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectoryPath = [paths objectAtIndex:0];
return documentsDirectoryPath;
}
@end