学步园

 




@interface UIProgressHUD : NSObject
 
- (void) show: (BOOL) yesOrNo;
 
- (UIProgressHUD *) initWithWindow: (UIView *) window;
 
@end
 

 
@interface HelloController : UIViewController
 
@end
 

 
@implementation HelloController
 

 
- (void) killHUD: (id) aHUD
 
{
 
 [aHUD show:NO];
 
 [aHUD release];
 
}
 
- (void) presentSheet
 
{
 
 id HUD = [[UIProgressHUD alloc] initWithWindow:self.view];
 
    [HUD setText:@"Downloading File. Please wait."];
 
    [HUD show:YES];
 
 
 
    [self performSelector:@selector(killHUD:) withObject:HUD afterDelay:5.0];
 
}

调用 presentSheet