UIPlerter关闭UIPicker后弹出

问题描述：

我有一个UIPicker，当选中一行时触发UIAlert。我试图在UIPicker“完成”按钮被按下并且UIPicker关闭后弹出警报。此时警报会在选中该行时触发。所以，当某人在选择器中滚动每一行时，UIAlert会一直弹出。UIPlerter关闭UIPicker后弹出

感谢您的帮助

这里的“完成”按钮代码：

-(IBAction)done{ 
    [UIView beginAnimations:nil context:nil]; 
    [UIView setAnimationDuration:0.5]; 
    CGAffineTransform transform = CGAffineTransformMakeTranslation(0, 480); 
    pickerView.transform = transform; 
    [UIView commitAnimations];

}

这里的选择器UIAlert代码样本显示“的情况下0”与所述提示消息一起：

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { 

UIColor *newColor; 
switch (row) { 
    case 0: 
     newColor = [UIColor yellowColor];  
     UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"alert" message:@"message" delegate:nil cancelButtonTitle:@"cancel" otherButtonTitles:nil]; 
     [alert show]; 
     [alert release]; 

     myLabel.text = @"sometext"; 
     break;

}

为什么您在选择该行时触发警报？按下时完成。 – Akshay

我不认为UIPickerView默认内置了一个“完成”按钮（或任何按钮）。 – chown

我会怎么做呢？我有一系列开关（行）{0}：}情况下触发警报。有没有办法保持这些，只有按'完成'时才触发警报？ – hanumanDev

答

-(IBAction)done{ 

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"alert" message:@"message"  delegate:nil cancelButtonTitle:@"cancel" otherButtonTitles:nil]; 
     [alert show]; 
     [alert release]; 

    [UIView beginAnimations:nil context:nil]; 
    [UIView setAnimationDuration:0.5]; 
    CGAffineTransform transform = CGAffineTransformMakeTranslation(0, 480); 
    pickerView.transform = transform; 
    [UIView commitAnimations]; 
} 


- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { 

UIColor *newColor; 
switch (row) { 
    case 0: 
     newColor = [UIColor yellowColor];  

     myLabel.text = @"sometext"; 
     break; 
} 

}

感谢您的帮助。完美地工作！ – hanumanDev

答

//Init the done button with an action to show an alert 
// and the target as self 
self.myBarBtnItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemDefault target:self action:@selector(showAlert:)]

那么你的行动：

// Show the alert with the currently selected row index of the picker 
- (void)showAlert:(id)sender { 
    NSUInteger selectedIndex = [myPickerView selectedRowInComponent:0]; 
    UIAlertView *alert = [[[UIAlertView alloc] initWithTitle:[NSString [email protected]"Row %f selected!", selectedIndex + 1] message:[NSString stringWithFormat:@"Row %d/%d selected.", selectedIndex + 1, [self pickerView:myPickerView numberOfRowsInComponent:0]] autorelease]; 
    [alert show]; 
}

答

优雅的方式：添加委托给您的观看动画看到UIView.h

（无效）setAnimationDidStopSelector：（SEL）选择器

[UIView beginAnimations:nil context:nil]; 
[UIView setAnimationDelegate:self]; 
[UIView setAnimationDidStopSelector:@selector(animationFinished:finished:context:) 
[UIView setAnimationWillStartSelector:self]; 
[UIView setAnimationDuration:0.5]; 
CGAffineTransform transform = CGAffineTransformMakeTranslation(0, 480); 
pickerView.transform = transform; 
[UIView commitAnimations];

和实施此方法：

- （空）animationFinished：（的NSString *）animationID完成：（BOOL）完成背景：（void *的）情况下

瞧

UIPlerter关闭UIPicker后弹出

相关推荐