当NSOutputStream完成数据发送后，如何关闭连接？
搜索后，我发现只有在服务器断开连接时才会调用事件NSStreamEventEndEncountered。不是如果OutputStream已完成要发送的数据。
StreamStatus始终返回0（连接已关闭）或2（连接打开）但从不返回4（写入数据）。
因为上面提到的两种方法都没有告诉我关于写入过程的信息，所以我无法找到确定Stream是否仍在写入的方法，或者它是否已经完成并且我现在可以关闭连接。
经过5天的googleling尝试我完全没有想法...任何帮助表示赞赏。感谢
根据要求编辑添加的代码：
- (void)startSend:(NSString *)filePath
{
BOOL success;
NSURL * url;
assert(filePath != nil);
assert([[NSFileManager defaultManager] fileExistsAtPath:filePath]);
assert( [filePath.pathExtension isEqual:@"png"] || [filePath.pathExtension isEqual:@"jpg"] );
assert(self.networkStream == nil); // don't tap send twice in a row!
assert(self.fileStream == nil); // ditto
// First get and check the URL.
...
....
.....
// If the URL is bogus, let the user know. Otherwise kick off the connection.
...
....
.....
if ( ! success) {
self.statusLabel.text = @"Invalid URL";
} else {
// Open a stream for the file we're going to send. We do not open this stream;
// NSURLConnection will do it for us.
self.fileStream = [NSInputStream inputStreamWithFileAtPath:filePath];
assert(self.fileStream != nil);
[self.fileStream open];
// Open a CFFTPStream for the URL.
self.networkStream = CFBridgingRelease(
CFWriteStreamCreateWithFTPURL(NULL, (__bridge CFURLRef) url)
);
assert(self.networkStream != nil);
if ([self.usernameText.text length] != 0) {
success = [self.networkStream setProperty:self.usernameText.text forKey:(id)kCFStreamPropertyFTPUserName];
assert(success);
success = [self.networkStream setProperty:self.passwordText.text forKey:(id)kCFStreamPropertyFTPPassword];
assert(success);
}
self.networkStream.delegate = self;
[self.networkStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
///////******** LINE ADDED BY ME TO DISONNECT FROM FTP AFTER CLOSING CONNECTION *********////////////
[self.networkStream setProperty:(id)kCFBooleanFalse forKey:(id)kCFStreamPropertyFTPAttemptPersistentConnection];
///////******** END LINE ADDED BY ME *********////////////
[self.networkStream open];
// Tell the UI we're sending.
[self sendDidStart];
}
}
- (void)stopSendWithStatus:(NSString *)statusString
{
if (self.networkStream != nil) {
[self.networkStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
self.networkStream.delegate = nil;
[self.networkStream close];
self.networkStream = nil;
}
if (self.fileStream != nil) {
[self.fileStream close];
self.fileStream = nil;
}
[self sendDidStopWithStatus:statusString];
}
- (void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode
// An NSStream delegate callback that's called when events happen on our
// network stream.
{
#pragma unused(aStream)
assert(aStream == self.networkStream);
switch (eventCode) {
case NSStreamEventOpenCompleted: {
[self updateStatus:@"Opened connection"];
} break;
case NSStreamEventHasBytesAvailable: {
assert(NO); // should never happen for the output stream
} break;
case NSStreamEventHasSpaceAvailable: {
[self updateStatus:@"Sending"];
// If we don't have any data buffered, go read the next chunk of data.
if (self.bufferOffset == self.bufferLimit) {
NSInteger bytesRead;
bytesRead = [self.fileStream read:self.buffer maxLength:kSendBufferSize];
if (bytesRead == -1) {
[self stopSendWithStatus:@"File read error"];
} else if (bytesRead == 0) {
[self stopSendWithStatus:nil];
} else {
self.bufferOffset = 0;
self.bufferLimit = bytesRead;
}
}
// If we're not out of data completely, send the next chunk.
if (self.bufferOffset != self.bufferLimit) {
NSInteger bytesWritten;
bytesWritten = [self.networkStream write:&self.buffer[self.bufferOffset] maxLength:self.bufferLimit - self.bufferOffset];
assert(bytesWritten != 0);
if (bytesWritten == -1) {
[self stopSendWithStatus:@"Network write error"];
} else {
self.bufferOffset += bytesWritten;
}
}
} break;
case NSStreamEventErrorOccurred: {
[self stopSendWithStatus:@"Stream open error"];
} break;
case NSStreamEventEndEncountered: {
// FOR WHATEVER REASON THIS IS NEVER CALLED!!!!
} break;
default: {
assert(NO);
} break;
}
}
答案 0 :(得分：4)
您的问题可以有两种解释。如果您要问的是＆＃34;我有一个NSOutputStream并且我写完了它，我该如何发出信号？＆＃34;然后答案就像调用close方法一样简单。
或者，如果您真正说的是＆＃34;我有一个NSInputStream，我想知道我什么时候到达流末端＆＃34;然后，您可以查看hasBytesAvailable或streamStatus == NSStreamStatusAtEnd。
为了您的信息，要实际获取状态NSStreamStatusWriting，您需要在此线程调用write:maxLength:时从另一个线程调用streamStatus方法。
---编辑：代码建议
您永远不会收到通知的原因是输出流从不完成（除非它是固定大小的流，而FTP流不是）。获得＆＃34;完成的输入流＆＃34;此时您可以关闭输出流。这是您原始问题的答案。
作为进一步的建议，我会跳过运行循环调度和＆＃34;事件处理＆＃34;除了处理输出流上的错误。然后我将读/写代码放入NSOperation子类并将其发送到NSOperationQueue。通过在该队列中保留对NSOperations的引用，您可以轻松取消它们，甚至可以通过添加percentComplete属性来显示进度条。我已经测试了下面的代码并且它有效。用FTP输出流替换我的内存输出流。您会注意到我已经跳过了验证，您当然应该保留这些验证。它们应该在NSOperation之外完成，以便更容易查询用户。
@interface NSSendFileOperation : NSOperation<NSStreamDelegate> {
NSInputStream *_inputStream;
NSOutputStream *_outputStream;
uint8_t *_buffer;
}
@property (copy) NSString* sourceFilePath;
@property (copy) NSString* targetFilePath;
@property (copy) NSString* username;
@property (copy) NSString* password;
@end
@implementation NSSendFileOperation
- (void) main
{
static int kBufferSize = 4096;
_inputStream = [NSInputStream inputStreamWithFileAtPath:self.sourceFilePath];
_outputStream = [NSOutputStream outputStreamToMemory];
_outputStream.delegate = self;
[_inputStream open];
[_outputStream open];
_buffer = calloc(1, kBufferSize);
while (_inputStream.hasBytesAvailable) {
NSInteger bytesRead = [_inputStream read:_buffer maxLength:kBufferSize];
if (bytesRead > 0) {
[_outputStream write:_buffer maxLength:bytesRead];
NSLog(@"Wrote %ld bytes to output stream",bytesRead);
}
}
NSData *outputData = [_outputStream propertyForKey:NSStreamDataWrittenToMemoryStreamKey];
NSLog(@"Wrote a total of %lu bytes to output stream.", outputData.length);
free(_buffer);
_buffer = NULL;
[_outputStream close];
[_inputStream close];
}
- (void) stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode
{
// Handle output stream errors such as disconnections here
}
@end
int main (int argc, const char * argv[])
{
@autoreleasepool {
NSOperationQueue *sendQueue = [[NSOperationQueue alloc] init];
NSSendFileOperation *sendOp = [[NSSendFileOperation alloc] init];
sendOp.username = @"test";
sendOp.password = @"test";
sendOp.sourceFilePath = @"/Users/eric/bin/data/english-words.txt";
sendOp.targetFilePath = @"/Users/eric/Desktop/english-words.txt";
[sendQueue addOperation:sendOp];
[sendQueue waitUntilAllOperationsAreFinished];
}
return 0;
}