UIAlertView button action not working - ios

Question

I have one alert view and when I click on yes button it is supposed to produce another alert view and a toast message,but it is not happening. I couldn't figure it out. Here is my code:
-(void)myMethod {
UIAlertView *saveAlert = [[UIAlertView alloc] initWithTitle:#"First Message"
message:#"My First message"
delegate:nil
cancelButtonTitle:#"No"
otherButtonTitles:#"Yes", nil];
saveAlert.tag=0;
[saveAlert performSelectorOnMainThread:#selector(show) withObject:nil waitUntilDone:NO];
}
This is the method I am using to provide the functionality for different alert views.
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
if(alertView.tag==0) {
if (buttonIndex == 0)
{
//Code for Cancel button
}
if (buttonIndex == 1)
{
//code for yes button
MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:self.navigationController.view animated:YES];
hud.mode = MBProgressHUDModeText;
hud.labelText = #"Successfully displayed First Message";
hud.margin = 10.f;
hud.yOffset = 150.f;
hud.removeFromSuperViewOnHide = YES;
[hud hide:YES afterDelay:3];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Second Message"
message:#"My second message"
delegate:nil
cancelButtonTitle:#"No"
otherButtonTitles:#"Yes",nil];
alert.tag=1;
[alert performSelectorOnMainThread:#selector(show) withObject:nil waitUntilDone:YES];
}
}
if (alertView.tag==1) {
if (buttonIndex == 0)
{
//Code for Cancel button
}
if (buttonIndex == 1)
{
//Code for yes Button
MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:self.navigationController.view animated:YES];
hud.mode = MBProgressHUDModeText;
hud.labelText = #"Succesfully displayed Second Message";
hud.margin = 10.f;
hud.yOffset = 150.f;
hud.removeFromSuperViewOnHide = YES;
[hud hide:YES afterDelay:3];
}
}
}
Can anyone help in finding the issue. Why I cannot get my second alert after clicking yes button in first alert?

Answer 1

You have not set the delegate for your UIAlertView and also make sure your delegate conforms to UIAlertViewDelegate protocol. Find the code snippet below.
You controller conforms to UIAlertViewDelegate protocol:
#interface YourViewController : UIViewController <UIAlertViewDelegate>
Create UIAlertView and set the deleagte:
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"First Message"
message:#"Show second message"
delegate:self
cancelButtonTitle:#"No"
otherButtonTitles:#"Yes", nil];
[alertView show];
Implement UIAlertViewDelegate delegate method:
- (void) alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
if( 0 == buttonIndex ){ //cancel button
[alertView dismissWithClickedButtonIndex:buttonIndex animated:YES];
} else if ( 1 == buttonIndex ){
[alertView dismissWithClickedButtonIndex:buttonIndex animated:YES];
UIAlertView * secondAlertView = [[UIAlertView alloc] initWithTitle:#"Second Message"
message:#"Displaying second message"
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[secondAlertView show];
}
}

Answer 2

You are specifying nil as the delegate for your alert views. You need to specify an object so the alertView:clickedButtonAtIndex: method can be called!

Answer 3

If you'd like to handle this more clear, you could use a block-based AlertView.
Create new file->Subclass of->UIAlertView
SuperAlertView.h
#import <UIKit/UIKit.h>
#class MySuperAlertView;
typedef void (^MySuperAlertViewBlock) (MySuperAlertView *alertView);
#interface MySuperAlertView : UIAlertView
- (instancetype) initWithTitle:(NSString *)title message:(NSString *)message;
- (void) addButtonWithTitle:(NSString *)buttonTitle block:(MySuperAlertViewBlock) block;
#end
SuperAlertView.m
#import "MySuperAlertView.h"
#interface MySuperAlertView()<UIAlertViewDelegate>
#property NSMutableArray *blocks;
#end
#implementation MySuperAlertView
- (instancetype)initWithTitle:(NSString *)title message:(NSString *)message
{
if (self = [super initWithTitle:title message:message delegate:self cancelButtonTitle:nil otherButtonTitles:nil])
{
self.blocks = [NSMutableArray array];
}
return self;
}
- (void)addButtonWithTitle:(NSString *)buttonTitle block:(MySuperAlertViewBlock)block
{
[self addButtonWithTitle:buttonTitle];
[self.blocks addObject:block ? [block copy] : [NSNull null]];
}
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
MySuperAlertViewBlock block = self.blocks[buttonIndex];
if ((id) block != [NSNull null]){
block(self);
}
}
#end
Usage:
MySuperAlertView *alertView = [[MySuperAlertView alloc] initWithTitle:#"Info" message:NSLocalizedString(#"EMAIL_SENT_SUCCESSFULL", nil)];
[alertView addButtonWithTitle:#"Ok" block:^(MySupertAlertView *alertView) {
// handle result from ok button here
}];
[alertView addButtonWithTitle:#"cancel" block:NULL];
dispatch_async(dispatch_get_main_queue(), ^{
[alertView show];
});