iphone 程序进度条实例

#import <UIKit/UIKit.h> @interface UIActionSheet (extended) - (void) setNumberOfRows: (NSInteger) rows; - (void) setMessage: (NSString *)message; @end #define PROGRESS_BAR 999 @interface HelloController : UIViewController <UIActionSheetDelegate> { float amountDone; UIActionSheet *baseSheet; } @property (nonatomic, retain) UIActionSheet *baseSheet; @end @implementation HelloController @synthesize baseSheet; - (void) incrementBar: (id) timer { amountDone += 1.0f; UIProgressView *progbar = (UIProgressView *)[self.baseSheet viewWithTag:PROGRESS_BAR]; [progbar setProgress: (amountDone / 20.0)]; if (amountDone > 20.0) { [self.baseSheet dismissWithClickedButtonIndex:0 animated:YES]; [timer invalidate]; } } - (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex { printf("User Pressed Button %d\n", buttonIndex + 1); [actionSheet release]; } - (void) presentSheet { if (!self.baseSheet) { baseSheet = [[UIActionSheet alloc] initWithTitle:@"Please Wait\n\nUpdating Internal Databases" delegate:self cancelButtonTitle:nil destructiveButtonTitle: nil otherButtonTitles: nil]; //below method is undocumentd in apple's doc,so you had better not use it //[baseSheet setNumberOfRows:5]; //[baseSheet setMessage:@"Updating Internal Databases"]; UIProgressView *progbar = [[UIProgressView alloc] initWithFrame:CGRectMake(50.0f, 40.0f, 220.0f, 90.0f)]; progbar.tag = PROGRESS_BAR; [progbar setProgressViewStyle: UIProgressViewStyleDefault]; [baseSheet addSubview:progbar]; [progbar release]; } UIProgressView *progbar = (UIProgressView *)[self.view viewWithTag:PROGRESS_BAR]; [progbar setProgress:(amountDone = 0.0f)]; [NSTimer scheduledTimerWithTimeInterval: 0.5 target: self selector: @selector(incrementBar:) userInfo: nil repeats: YES]; [baseSheet showInView:self.view]; } - (id) init { if (self = [super init]) self.title = @"Hello World"; return self; } - (void)loadView { UIView *contentView = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]]; self.view = contentView; contentView.backgroundColor = [UIColor whiteColor]; [contentView release]; // reduce retain count by one self.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc] initWithTitle:@"Do It" style:UIBarButtonItemStylePlain target:self action:@selector(presentSheet)] autorelease]; } - (void) dealloc { if (self.baseSheet) [self.baseSheet release]; [super dealloc]; } @end @interface SampleAppDelegate : NSObject <UIApplicationDelegate> @end @implementation SampleAppDelegate - (void)applicationDidFinishLaunching:(UIApplication *)application { UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:[[HelloController alloc] init]]; [window addSubview:nav.view]; [window makeKeyAndVisible]; } @end int main(int argc, char *argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; int retVal = UIApplicationMain(argc, argv, nil, @"SampleAppDelegate"); [pool release]; return retVal; }