Question

我有一个UIPicker，当选择一行时触发UIAlert。在UIPicker“完成”按钮被按下并且UIPicker关闭后，我正在尝试弹出警报。当选择行时，警报会触发。因此，当有人滚动选择器中的每一行时，UIAlert会不断弹出。

感谢您的帮助

这是'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];

}

这是一个选择器UIAlert代码的示例，显示“case 0”以及警告消息：

- (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;

}

Answer 1

//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:)]

然后你的行动：

// 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 stringWithFormat@"Row %f selected!", selectedIndex + 1] message:[NSString stringWithFormat:@"Row %d / %d selected.", selectedIndex + 1, [self pickerView:myPickerView numberOfRowsInComponent:0]] autorelease];
    [alert show];
}

Answer 2

-(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;
}

}

在UIPicker关闭后UIAlert弹出

3 个答案: