iOS 多次请求只执行一次

使用这个函数来实现
- (void)performSelector:(SEL)aSelector withObject:(id)anArgument afterDelay:(NSTimeInterval)delay;

例子：
dic是要传的参数，我的是一个字典类型
[self performSelectorOnMainThread:@selector(sendData:) withObject:dic waitUntilDone:NO];

//实现方法
-(void)sendData: (NSDictionary *)dic {
[self performSelector:@selector(send:) withObject:dic afterDelay:10];
}

-(void)send: (NSDictionary *)dic {
NSLog(@”%@”,dic);
}