How to detect change in UISegmentedControl from a separate IBAction - objective-c

Question

I have a UISegmentedControl button with three segments.
In ViewController.m this is working just fine -- pressing the buttons fires the correct methods.
I have another separate UIButton that when it is pressed it needs to first CHECK the state of the UISegmentedControl (to see which button is currently pressed) and then fire a method according to that segment value.
Here is my code for that separate UIButton. The button itself is working, but I cannot seem to figure out how to GET the current value of the segment of the UISegmentedControl.
Many thanks for any assistance here.
I am new to OBJ-C. I know how to do this in VisualBasic, so answers that are on the more verbose side would be most appreciated as I need to know the 'why'. Thank you.
- (IBAction)decodeButton:(id)sender {
UISegmentedControl *segment = [UISegmentedControl alloc]; // THIS DOES NOT WORK.
if (segment.selectedSegmentIndex == 0) {
decode(textToDecode);
} else if(segment.selectedSegmentIndex == 1) {
decode1(textToDecode);
} else if(segment.selectedSegmentIndex == 2) {
decode2(textToDecode);
}
}

Answer 1

Here is a Tutorial using UISegmentedControl in iOS.
Just Create a Reference object and wire it properly to File Owner.
IBOutlet UISegmentedControl *segmentedControl;
Then set property
#property (strong, nonatomic) IBOutlet UISegmentedControl * segmentedControl;
Synthesize in .m file
#synthesize segmentedControl;
Now You can Access the selected index at any time.
- (IBAction)decodeButton:(id)sender {
if (segmentedControl.selectedSegmentIndex == 0) {
decode(textToDecode);
} else if(segmentedControl.selectedSegmentIndex == 1) {
decode1(textToDecode);
} else if(segmentedControl.selectedSegmentIndex == 2) {
decode2(textToDecode);
}
}

Answer 2

Your code alloc every time UISegmentedControl in the button press action. So use the following code for sUISegmentedControl creation and its action .
SegmentChangeView=[[UISegmentedControl alloc]initWithItems:[NSArray arrayWithObjects:#"Segment1",#"Segment2",#"Segment3",nil]];
SegmentChangeView.frame=CGRectMake(5, 44, self.view.bounds.size.width-10, 33);
SegmentChangeView.selectedSegmentIndex=0;
SegmentChangeView.segmentedControlStyle=UISegmentedControlStyleBar;
SegmentChangeView.momentary = YES;
[SegmentChangeView setTintColor:[UIColor blackColor]];
NSDictionary *attributes =[NSDictionary dictionaryWithObjectsAndKeys:[UIFont fontWithName:#"Arial" size:13],UITextAttributeFont,nil];
[SegmentChangeView setTitleTextAttributes:attributes forState:UIControlStateNormal];
[SegmentChangeView addTarget:self action:#selector(SegmentChangeViewValueChanged:) forControlEvents:UIControlEventValueChanged];
SegmentChangeView.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleBottomMargin;
[self.view addSubview:SegmentChangeView];
-(IBAction)SegmentChangeViewValueChanged:(UISegmentedControl *)SControl
{
if (SControl.selectedSegmentIndex==0)
{
decode(textToDecode);
}
else if (SControl.selectedSegmentIndex==1)
{
decode1(textToDecode);
}
else if (SControl.selectedSegmentIndex==2)
{
decode2(textToDecode);
}
}

Answer 3

You should remove UISegmentedControl *segment = [UISegmentedControl alloc] ; from your code, as it allocs anew instance of your UISegmentedControl every time, instead,
create an outlet for you UISegmentController like
#property (strong, nonatomic) IBOutlet UISegmentedControl * segment;
and then later at any point in your viewcontroller.m file, you can get the currently selected segment by using
segment.selectedSegmentIndex;
Hope this make sense,
Regards

Answer 4

Try like this
- (IBAction)segmentedControlChanged:(id)sender
{
UISegmentedControl *s = (UISegmentedControl *)sender;
if (s.selectedSegmentIndex == 1)
{
//code
}
else
{
//code
}
}

Answer 5

This code means you are creating a new Object on every click
UISegmentedControl *segment = [UISegmentedControl alloc] ;
The thing you have to do take IBOutlet (Property) of your segmentedControl then I will work for you. dont create a new object in the button method. when you will make a IBOutlet it will be link with at segmentControl and your code will work that time . Thanks