在我的应用中,我需要在通过网络执行某些操作时使用轮询而不是运行循环。
我的代码如下所示
-(id) init
{
self = [super init];
if (self) {
CFReadStreamRef readStream;
CFWriteStreamRef writeStream;
NSURL *host = [NSURL URLWithString:@"http://localhost/"];
CFStreamCreatePairWithSocketToHost(NULL, (__bridge CFStringRef)([host host]), 5525, &readStream, &writeStream);
_writeStream = [[NSOutputStream alloc] initToMemory];
_readStream = (__bridge NSInputStream *)(readStream);
_writeStream = (__bridge NSOutputStream *)(writeStream);
[_readStream open];
[_writeStream open];
}
return self;
}
-(void) writeIntoNetworkWith:(NSString *)info
{
if ([self.writeStream hasSpaceAvailable]) {
NSData * data = [[NSData alloc] initWithData:[info dataUsingEncoding:NSUTF8StringEncoding]];
[self.writeStream write:[data bytes] maxLength:[data length]];
}
else
NSLog(@"Write Stream Not Available");
}
-(NSString *) readFromNetwork
{
NSMutableString * send;
if ([self.readStream hasBytesAvailable])
{
uint8_t buffer[1024];
int len;
len = [self.readStream read:buffer maxLength:1024];
if (len >0)
{
send = [[NSMutableString alloc] initWithBytes:buffer length:len encoding:NSUTF8StringEncoding];
}
}
return send;
}
和viewControler.m如下
- (void)viewDidLoad {
[super viewDidLoad];
SuperTestClass * n = [[SuperTestClass alloc]init];
NetworkReadAndWrite * obj = [[NetworkReadAndWrite alloc]init];
[obj writeIntoNetworkWith:@"Hello World"];
[obj readFromNetwork];
}
接收一些数据的服务器回复" Hello"消息
运行上面的代码它总是返回noSpaceAvailable / noBytesAvailable分别从输出和输入流写入或读取。
我想知道我是否在这里遗漏了什么。
答案 0 :(得分:1)
想出来。是一个愚蠢的错误。应该等到读取流有可读取的字节。
while(1)
{
if ([self.readStream hasBytesAvailable])
{
uint8_t buffer[1024];
int len;
len = [self.readStream read:buffer maxLength:1024];
if (len >0)