我必须从服务器下载图像，但我不想创建 NSURLConnection，我知道 UIKit 不是线程安全的，所以我尝试了这个，只需要确认这是否安全或是否会导致崩溃（截至现在它工作正常。）我尝试了以下
看开关的案例2。
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
switch (indexPath.row) {
case 0:
{
CreateNewSurveyViewController *vc=[[CreateNewSurveyViewController alloc] init];
[self.navigationController pushViewController:vc animated:YES];
[vc release];
break;
}
case 1:{
MySurveyViewController *mySurveyViewController=[[MySurveyViewController alloc] init];
[self.navigationController pushViewController:mySurveyViewController animated:YES];
[mySurveyViewController release];
break;
}
case 2:{
self.progressHud.hidden = NO;
[self performSelectorInBackground:@selector(loadProfileImage) withObject:nil];
break;
}
default:
break;
}
}
-(void)loadProfileImage {
NSData* profileImageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:self.userAccount.profileImageURL]];
[self performSelectorOnMainThread:@selector(launchSettingsView:) withObject:profileImageData waitUntilDone:YES];
}
-(void)launchSettingsView:(NSData*)profileImageData {
self.userAccount.userImage = [UIImage imageWithData:profileImageData];
self.progressHud.hidden = YES;
SettingsViewController* settingsViewController=[[SettingsViewController alloc] init];
settingsViewController.userAccount = self.userAccount;
settingsViewController.delegate = self;
[self.navigationController pushViewController:settingsViewController animated:YES];
[settingsViewController release];
}