IPhone之UIProgressView

源自：http://hi.baidu.com/aidfan/blog/item/014e5d0ecc6b15de7acbe17e.html   做了一个小Deme,是通过UIActionSheet来显示UIProgressView进度条的。     代码如下：   @interface View21 : UIViewController <UIActionSheetDelegate> { float amountDone; UIProgressView *progressView; UIActionSheet *actionSheet; UIView *mainView; }         实现方法：   #import "View21.h"   @implementation View21 @synthesize actionSheet;   - (void)loadView { mainView=[[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)]; self.view=mainView; self.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc] initWithTitle:@"进度条" style:UIBarButtonItemStylePlain target:self action:@selector(action:)] autorelease]; }       -(void) action: (UIBarButtonItem *) item { amountDone = 0.0f;     self.actionSheet = [[[UIActionSheet alloc] initWithTitle:@"正在加载数据请等待/n/n/n" delegate:nil cancelButtonTitle:nil destructiveButtonTitle: nil otherButtonTitles: nil] autorelease]; progressView = [[UIProgressView alloc] initWithFrame:CGRectMake(0.0f, 40.0f, 220.0f, 90.0f)];     [progressView setProgressViewStyle: UIProgressViewStyleDefault];     [actionSheet addSubview:progressView];     [progressView release];       //建立更新  nstimer     [progressView setProgress:(amountDone = 0.0f)]; [NSTimer scheduledTimerWithTimeInterval: 0.35 target: self selector:@selector(incrementBar:) userInfo: nil repeats: YES]; //向actionSheet 添加view数据条     [actionSheet showInView:mainView]; progressView.center = CGPointMake(actionSheet.center.x, progressView.center.y); }   // nstimer  事件 - (void) incrementBar: (id) timer {     amountDone += 1.0f;     [progressView setProgress: (amountDone / 20.0)]; //结束 actionSheet if (amountDone > 20.0) { [self.actionSheet dismissWithClickedButtonIndex:0 animated:YES]; self.actionSheet = nil; [timer invalidate]; } } }