UIAlert to popup after the UIPicker is closed

Question

I have a UIPicker that triggers a UIAlert when a row is selected. I'm trying to have the alert popup after the UIPicker "done" button is pressed and the UIPicker is closed. At the moment the alert triggers when the row is selected. So, as someone scrolls through each row in the picker a UIAlert keeps popping.

thanks for any help

here's the 'done' button code:

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

}

here's a sample of the picker UIAlert code showing 'case 0' along with the alert message:

- (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;

}

Why are you triggering the alert when the row is selected? Do it when done is pressed. — Akshay, Sep 29 '11 at 03:29
I dont think a UIPickerView has a "done" button (or any button) built in by default. — chown, Sep 29 '11 at 03:32
how would I go about doing that? I have a series of switch (row) { case 0: } cases that trigger the alert. is there a way to keep these and only trigger the alert when the 'done' is pressed? — hanumanDev, Sep 29 '11 at 03:34
place the code you are using to handle done button press event and alert presenting. — Rahul Sharma, Sep 29 '11 at 03:52

score 2 · Answer 1 · answered Sep 29 '11 at 04:13

//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:)]

Then your action:

// 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];
}

score 1 · Accepted Answer · answered Sep 29 '11 at 05:29

-(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;
}

}

score 0 · Answer 3 · answered Sep 29 '11 at 08:57

Elegant way : Add delegate to your view animation see UIView.h

(void)setAnimationDidStopSelector:(SEL)selector

[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];

and implement this method:

-(void)animationFinished:(NSString *)animationID finished:(BOOL)finished context:(void *)context

voilà

UIAlert to popup after the UIPicker is closed

3 Answers3