NSOperation和NSURLConnection

bagusflyer — Wed, 23 Feb 2011 05:48:27 +0000

最近一个客户向我汇报了一个程序的问题。经过分析发现问题是NSURLConnection没有正常工作。记得以前测试时没有问题啊。后来上网查到原来在iOS 4.0以后，NSURLConnection无法在NSOperation中正常运行，换句话说，NSURLConnection只能运行于主线程。解决方法其实倒是蛮简单（比如我的程序在download中）：

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-(void)download
{
// NSURLConnectionn won't work if it's not in the main thread
if (![NSThread isMainThread])
{
[self performSelectorOnMainThread:@selector(download) withObject:nil waitUntilDone:NO];
return;
}

NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:_urlString]];
_connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
}

跨平台代码分享之一 – 线程

bagusflyer — Sun, 01 Nov 2009 07:40:52 +0000

有些iPhone程序是直接从其他平台移植过来，或者说你喜欢使用cpp，再或者是你打算让你的程序跨越平台，那么使用跨平台的cpp库无疑是一个很好的选择。这就是本系列的主题。

第一篇为大家分享一段本人自用的线程类。它使用pthread，因此可以跨平台使用（windows下需要下载pthread库）。由于程序很简单，就不做什么说明了。

头文件：

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#ifndef _UTILS_THREAD_H_
#define _UTILS_THREAD_H_

#include

namespace utils
{

class CThread
{

public:
typedef void( ThreadCallback( void * ) );

typedef enum
{
THREAD_STOP = 0,
THREAD_RUN,
THREAD_PAUSE
} ThreadState;

CThread(ThreadCallback* callback, void* pUserData);

~CThread();

ThreadState state() const { return m_state; }

ThreadCallback* callback() const { return m_pCallback; }

void* userData() const { return m_pUserdata; }

pthread_t thread() const { return m_thread; }

void run();

void stop();

void pause();

private:

ThreadCallback* m_pCallback;
pthread_t m_thread;
ThreadState m_state;
unsigned int m_uiThreadId;
void* m_pUserdata;

};

}

#endif // _UTILS_THREAD_H_

cpp文件:

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#include "utils/Thread.h"

namespace utils
{

void* threadRun( void *_ptr )
{
unsigned char run = 1;
CThread* theThread = ( CThread* )_ptr;

while( run )
{

switch( theThread->state() )
{

case CThread::THREAD_RUN:
{
CThread::ThreadCallback* callback = theThread->callback();

if ( callback )
callback( theThread->userData() );

break;
}

case CThread::THREAD_STOP:
{
run = 0;
break;
}

case CThread::THREAD_PAUSE:
{
msleep(50);
}
}
}

return NULL;

}

CThread::CThread(ThreadCallback* callback, void* pUserData)
: m_pCallback(callback),
m_pUserdata(pUserData),
m_state(THREAD_PAUSE)
{
m_uiThreadId = pthread_create( &m_thread,NULL,threadRun, (void *)this );
}

CThread::~CThread()
{
pthread_join( m_thread, NULL );
}

void CThread::run()
{
m_state = THREAD_RUN;
}

void CThread::stop()
{
m_state = THREAD_STOP;
}

void CThread::pause()
{
m_state = THREAD_PAUSE;
}

}

msleep函数：

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#include <sys/time.h>

void msleep( unsigned int ms )
{

int microsecs;
struct timeval tv;
microsecs = ms * 1000;
tv.tv_sec = microsecs / 1000000;
tv.tv_usec = microsecs % 1000000;
select( 0, NULL, NULL, NULL, &tv );

}

使用方法：

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void* onRun(void* ptr)
{

......

}

utils::CThread* m_pThread = new utils::CThread((ThreadCallback*)onRun,NULL);

m_pThread->run();

......

delete m_pThread;