一 UIAlertView的使用
UIAlertView* alert=[[UIAlertView alloc] initWithTitle:@"提示" message:@"標籤獲取失敗" delegate:self cancelButtonTitle:@"確定" otherButtonTitles:nil];
[alert show];
二 UIAlertView彈出後2s讓其自動消失
兩種方法：
(1)結合NSTimer
定義UIAlertView *baseAlert;
- (void) performDismiss: (NSTimer *)timer {
[baseAlert dismissWithClickedButtonIndex:0 animated:NO];//important
[baseAlert release];
baseAlert = NULL;
}
- (void) presentSheet {
baseAlert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"\nMessage Message Message " delegate:self cancelButtonTitle:nil otherButtonTitles: nil];
[NSTimer scheduledTimerWithTimeInterval:2.0f target:self selector: @selector(performDismiss:) userInfo:nil repeats:NO];
[baseAlert show]; }
(2)使用PerformSelector：withObject：afterDelay：方法
- (void) dimissAlert:(UIAlertView *)alert {
if(alert) {
[alert dismissWithClickedButtonIndex:[alert cancelButtonIndex] animated:YES];
[alert release];
}
}
- (void)showAlert{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"title" message:@"message" delegate:nil cancelButtonTitle:nilotherButtonTitles:nil];
[alert show];
[self performSelector:@selector(dimissAlert:) withObject:alert afterDelay:2.0];
}