iPhone 開發筆記04: 利用 NSTimer 來顯示 UIProgressView 的進度

// @interface
IBOutlet UIProgressView *progressBar;
@property (nonatomic, retain) IBOutlet UIProgressView *progressBar;
- (IBAction)startTheTimer:(id)sender;
- (void)goProgress:(NSTimer *)theTimer;

// @implementation
@synthesize progressBar;
......
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接著, 將 UIButton 上的 Touch Up Inside 事件, 連到以下的 startTheTimer 這個 IBAction:

- (IBAction)startTheTimer:(id)sender {
// set Progress to 0.0
[progressBar setProgress:0.0];

[NSTimer scheduledTimerWithTimeInterval:0.2f target:self selector:@selector(goProgress:) userInfo:nil repeats:YES];
}

- (void)goProgress:(NSTimer *)theTimer {
float progress = progressBar.progress;
progress = progress * 10 + 1;

[progressBar setProgress:progress * 0.1];

if (progress >= 10) {
// stop NSTimer
[theTimer invalidate];
}

}