我正在开发一个连接到服务器并从中下载数据的项目。如果连接中断，我喜欢支持恢复下载。我的方法是将下载的数据部分保存到目标文件中；如果连接中断，我想使用 connection:didWriteData:totalBytesWritten:expectedTotalBytes 标记下载的部分，然后使用服务器从停止的部分恢复。
我的代码:
- (IBAction)connectToServer:(UIButton *)sender
{
// setup url and send request to server
NSURL *url = [NSURL URLWithString:BASED_URL];
self.urlRequest = [[NSMutableURLRequest alloc] initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
self.urlConnection = [[NSURLConnection alloc] initWithRequest:self.urlRequest delegate:self];
// start receive data if connection established
if (self.urlConnection){
self.receivedData = [NSMutableData data];
NSLog(@"starting to receive data");
} else {
// handle error
NSLog(@"failed to connect to server");
}
}
- (void)doSomethingWithData
{
// handle data here
}
#pragma NSURLConnectionDataDelegate
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
[self.receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
// received data
[self.receivedData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
// error connection
NSLog(@"connection failed");
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSLog(@"Data receiving succeed, received: %d bytes of data", [self.receivedData length]);
}
- (void)connection:(NSURLConnection *)connection didWriteData:(long long)bytesWritten totalBytesWritten:(long long)totalBytesWritten expectedTotalBytes:(long long)expectedTotalBytes
{
NSLog(@"not getting called");
}
我的问题是为什么“connection:didWriteData:totalBytesWritten:expectedTotalBytes”方法从未被调用过？
非常感谢! 克里斯
最佳答案
你有没有在 .h 文件中添加这个:
@interface yourViewContoller : UIViewController <NSURLConnectionDataDelegate, NSURLConnectionDelegate>
关于iphone - NSURLConnection 下载委托(delegate)方法未被调用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12558484/