摘要： 1.什么是NSRunLoop？我们会经常看到这样的代码：12345678910-(IBAction)start:(id)sender{pageStillLoading=YES;[NSThreaddetachNewThreadSelector:@selector(loadPageInBackground:)toTarget:self withObject:nil];[progress setHidden:NO];while(pageStillLoading){[NSRunLoopcurrentRunLoop]runMode:NSDefaultRunLoopMode beforeDate:[NSD 阅读全文