Download didReceiveData在恢复下载时仅被调用一次
我有一个问题，我真的可以做一些帮助请 我正在使用NSURLconnection下载一个27MB的大文件。当没有网络中断时，代码工作正常。为了允许网络问题和仅部分下载的文件，我添加了代码来检查文件的下载量，然后使用服务器请求下载缺少的部分 如果我下载了部分文件，停止程序运行，然后再次运行，代码就会正常工作——下载从停止的地方开始，我就有了完整的文件 然而，如果我第二次点击下载按钮而不停止程序，那么didReceiveData只会被调用一次，并且只向文件添加200KB，它告诉我文件已成功下载 请帮帮我-我花了很多时间试图找出我做错了什么 代码如下：Download didReceiveData在恢复下载时仅被调用一次,download,nsurlconnection,resume,Download,Nsurlconnection,Resume,我有一个问题，我真的可以做一些帮助请 我正在使用NSURLconnection下载一个27MB的大文件。当没有网络中断时，代码工作正常。为了允许网络问题和仅部分下载的文件，我添加了代码来检查文件的下载量，然后使用服务器请求下载缺少的部分 如果我下载了部分文件，停止程序运行，然后再次运行，代码就会正常工作——下载从停止的地方开始，我就有了完整的文件 然而，如果我第二次点击下载按钮而不停止程序，那么didReceiveData只会被调用一次，并且只向文件添加200KB，它告诉我文件已成功下载 请帮帮
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse*)response;
NSLog(@"Response code = %d",httpResponse.statusCode );
file = [NSFileHandle fileHandleForUpdatingAtPath:filename] ;// file is in .h
if (file) {
[file seekToEndOfFile];
}
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
if (file) {
[file seekToEndOfFile];
NSLog(@"file is %@",file);
}
[self.file writeData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
if([[NSFileManager defaultManager] fileExistsAtPath:filename])
{
[file closeFile];
file = nil;
theConnection = nil;
filename = nil;
theRequest = nil;
}
NSLog(@"Connection failed! Error - %@ %@",
[error localizedDescription],
[[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
[file closeFile];
file = nil;
theConnection = nil;
filename = nil;
}
- (IBAction)downloadFile:(id)sender {
filename = [[NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:movie1]; // filename is in .h file
theRequest=[NSMutableURLRequest requestWithURL:[NSURL URLWithString:movieDownload1] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
NSUInteger downloadedBytes = 0;
NSFileManager *fm = [NSFileManager defaultManager];
if ([fm fileExistsAtPath:filename]) {
NSError *error = nil;
NSDictionary *fileDictionary = [fm attributesOfItemAtPath:filename error:&error];
if (!error && fileDictionary)
downloadedBytes = [fileDictionary fileSize];
} else {
[fm createFileAtPath:filename contents:nil attributes:nil];
}
if (downloadedBytes > 0) {
NSString *requestRange = [NSString stringWithFormat:@"bytes=%d-",downloadedBytes];
[theRequest setValue:requestRange forHTTPHeaderField:@"Range"];
}
theConnection = nil;
theConnection = [NSURLConnection connectionWithRequest:theRequest delegate:self];
}
您可以尝试以下代码片段，而不是在didReceiveResponse和didReceiveData中使用seekToEndOfFile。这对我很有效
- (id)initWithURL:(NSString *)downloadString
{
if (![super init])
return nil;
// Construct the URL to be downloaded
self.downloadURL = [[NSURL alloc]initWithString:downloadString];
self.downloadData = [[NSMutableData alloc] init];
self.downloadedFilename = [[self.downloadURL path] lastPathComponent];
[self downloadFile];
return self;
}
-(void) downloadFile
{
// set the filePath
docFolderPath = [NSHomeDirectory() stringByAppendingPathComponent: [NSString stringWithFormat: @"Documents/%@", self.downloadedFilename]];
self.downloadStream = [NSOutputStream outputStreamToFileAtPath:docFolderPath append:NO];
if (!self.downloadStream)
{
self.error = [NSError errorWithDomain:[NSBundle mainBundle].bundleIdentifier
code:-1
userInfo:@{@"message": @"Unable to create NSOutputStream", @"function" : @(__FUNCTION__), @"path" : self.downloadedFilename}];
return;
}
[self.downloadStream open];
self.downloadConnection = [[NSURLConnection alloc] initWithRequest:downloadRequest delegate:self];
[self.downloadConnection start];
}
//code snippet for the Resume functionality after your downloading gets paused/cancel
-(void) resumeInterruptedDownload
{
NSFileManager *fm = [NSFileManager defaultManager];
if ([fm fileExistsAtPath:docFolderPath])
{
NSError *error = nil;
NSDictionary *fileDictionary = [fm attributesOfItemAtPath:docFolderPath
error:&error];
if (!error && fileDictionary)
self.downloadedBytes = [fileDictionary fileSize];
} else
{
[fm createFileAtPath:docFolderPath contents:nil attributes:nil];
}
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:self.downloadURL cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:30.0];
// Define the bytes we wish to download.
if(self.downloadedBytes != 0)
{
NSString *range = [NSString stringWithFormat:@"bytes=%i-", self.downloadedBytes];
[request setValue:range forHTTPHeaderField:@"Range"];
}
// Data should immediately start downloading after the connection is created.
self.downloadConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:TRUE];
}