我一直在尝试为我的ios应用程序启动并运行一个基本的tcp客户端,但遇到了一个似乎无法正常工作的块。
到目前为止,我可以连接,发送一个在服务器端接收到的消息,但是我的应用程序崩溃了。
客户h
#import <Foundation/Foundation.h>
@interface Client : NSObject <NSStreamDelegate>
{
NSInputStream *inputStream;
NSOutputStream *outputStream;
}
-(void)initNetworkCommunication;
-(void)send:(NSString*)message;
@end
客户
#import "Client.h"
@implementation Client
- (void)initNetworkCommunication {
CFReadStreamRef readStream;
CFWriteStreamRef writeStream;
CFStreamCreatePairWithSocketToHost(NULL, (CFStringRef)@"10.0.1.51", 7769, &readStream, &writeStream);
inputStream = ( NSInputStream *)CFBridgingRelease(readStream);
outputStream = ( NSOutputStream *)CFBridgingRelease(writeStream);
[inputStream setDelegate:self];
[outputStream setDelegate:self];
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[inputStream open];
[outputStream open];
}
- (void)send:(NSString*)message
{
NSData *data = [[NSData alloc] initWithData:[message dataUsingEncoding:NSUTF8StringEncoding]];
[outputStream write:[data bytes] maxLength:[data length]];
}
- (void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent {
NSLog(@"stream event %i", streamEvent);
switch (streamEvent) {
case NSStreamEventOpenCompleted:
NSLog(@"Stream opened");
break;
case NSStreamEventHasBytesAvailable:
if (theStream == inputStream) {
uint8_t buffer[1024];
int len;
while ([inputStream hasBytesAvailable]) {
len = [inputStream read:buffer maxLength:sizeof(buffer)];
if (len > 0) {
NSString *output = [[NSString alloc] initWithBytes:buffer length:len encoding:NSASCIIStringEncoding];
if (nil != output) {
NSLog(@"server said: %@", output);
}
}
}
}
break;
case NSStreamEventErrorOccurred:
NSLog(@"Can not connect to the host!");
break;
case NSStreamEventEndEncountered:
NSLog(@"End Encountered!");
[theStream close];
[theStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
theStream = nil;
break;
default:
NSLog(@"Unknown event");
}
}
@end
控制台中的输出是
2013-10-03 17:01:38.542 MMORPG[6076:70b] stream event 1
2013-10-03 17:01:38.543 MMORPG[6076:70b] Stream opened
2013-10-03 17:01:43.495 MMORPG[6076:70b] stream event 4
2013-10-03 17:01:43.495 MMORPG[6076:70b] Unknown event
似乎,我的消息被发送,我收到流事件4,然后我得到一个坏的访问崩溃。问题是我不知道什么东西在访问时有问题?
任何帮助都将不胜感激!
最佳答案
问题是NSStream
保留对其委托的assign/unsafe\u引用。如果在关闭和释放流之前释放了委托,则流将尝试对其现在已释放的委托调用方法,从而导致崩溃。解决方案是确保其他某个对象具有对客户端的强引用,从而阻止其早期释放,或者确保在释放其委托之前关闭并释放流。