I can't understand the logic og button tags. Can someone tell me how to use button tags?
For eg. There are two buttons on my view and I want to print something depending on their tags like:
if(button.tag==???)x{
}etc.
When you create the button, you can set it's tag.
myButton1.tag = 0;
myButton2.tag = 1;
Or if you're using interface builder, there's a field in the inspector to set the tag.
I assume you've linked the buttons to call the same action when they're pressed, or else you wouldn't be needing to distinguish by tag, so your method should look like:
- (IBAction)buttonPressed:(id)sender
{
UIButton *aButton = (UIButton *)sender; // we know the sender is a UIButton object, so cast it
if (aButton.tag == 0)
{
// button 1 pressed
}
else if (aButton.tag = 1)
{
// button 2 pressed
}
}
Yeah you can use the tag to retrieve the UIButtons, and apply the same logic with UIVIews (have a look at this method remembering that UIButton inherits from UIView).
Specifically where do you have problems? Can you post some code/pseudo-code of yours?
Related
I have 28 buttons in my application. I need to control them in a single function. All I want to do is make all the buttons visible. I gave tags to the buttons. I tried it with a for loop but I couldn't do it how can I solve this problem?
(IBAction)btnAction:(id)sender{
UIButton *btnPressed = (UIButton *)sender;
NSUInteger i=btnPressed.tag;
for(i=0; i<29; i++)
{
btnPressed.hidden=NO;
}
}
Instead of tags, use an IBOutletCollection. So now you have a single NSArray pointing to all of the buttons. Now just cycle through that NSArray.
You can create a single IBAction method, check tag values and then do what you want to do
- (IBAction)btnAction:(id)sender{
UIButton *btnPressed = (UIBUtton *)sender;
// Check button tags and write code accordingly //
}
use IBOutletCollection. see the following link for your answer.
IBOutletCollection
and
IBOutletCollection (UIbutton)
IBOutletCollection of UIButtons - changing selected state of buttons
I have made a horizontal scroll view with images and buttons in it using a for loop, what i want to do now is when a button is pressed, open the image it corresponds to full screen. The issue im having is determining which button has been pushed. I am using :
[button addTarget:self action:#selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
then :
-(void)buttonPressed:(UIButton *)sender {}
What can i do to fix this? Thanks
Which button has been pushed
Create a property to store a tag. In the buttonPressed method set the property to sender.tag
Now you can know which was the button who got pressed last.
The sender is the button that the user has tapped, so when you create the buttons you could use the tag property and set it to an index of an array where you hold your images. But this could be a bit unstable if you change the order or amount of images or buttons for example so be prepared to check for that.
one way to do so is to keep references of your button (with a property, an attribute in your class) and test if it is the good one in your buttonPressed method
- (void)buttonPressed:(UIButton *)sender {
if (sender == self.myButton) {
// DO YOUR WORK HERE
}
}
you can also create a method for this and only this one button
by the way it is better to say
- (IBAction)buttonPressed:(UIButton *)sender
you then can set the target of your button in the interface builder interface
set tag for each button in the for loop but.tag=i;
-(void)buttonPressed:(UIButton *)sender {
if (sender.tag==1){
//display image 1
}
else if ....
}
I am developing for iPhone the app I am developing has many buttons and I want all buttons to call the same class but with different parameter
for example I want button1 to call the displayimageclass
and button2 should call the same class displayimageclass so, how to different method call same class and in that same class how to fetch different button from where it is call to particular class.
That is pretty much standard. Just define as many IBAction methods as you need.
In the viewController's .h file:
- (IBAction)actionButton1:(UIButton *)sender;
- (IBAction)actionButton2:(UIButton *)sender;
- (IBAction)actionButton3:(UIButton *)sender;
And in its .m file:
{
//react here to button1 pressed
}
- (IBAction)actionButton1:(UIButton *)sender
{
//react here to button1 pressed
}
- (IBAction)actionButton2:(UIButton *)sender
{
//react here to button2 pressed
}
- (IBAction)actionButton3:(UIButton *)sender
{
//react here to button3 pressed
}
Then associate the action with the Button's events (TouchUpInside would be most appropriate, I guess).
You should add tag property to your buttons.
Suppose your buttons are
button1.tag =1;
button2.tag =2;
button3.tag =3;
When you click any button, NSLog shows related button tag number. i.e You will get your result what you want.
- (IBAction)buttonClicked:(id)sender {
UIButton* button = (UIButton *)sender;
NSLog(#"The number of tag:%d",button.tag);
}
I think it will be helpful to you.
you can implement your action method like this:
- (IBAction)action:(UIButton *)sender
{
//sender will be different for different button
}
Set tag value for buttons and get those buttons like
- (IBAction)action:(UIButton *)sender
{
UIButton *btn = (UIButton*)sender;
}
Are you looking for
1) several buttons performing the same method with the same behavior
2) several buttons performing the same method but having different behavior based on the button characteristics
3) each button performing its own method.
1) You can register several buttons on the same IBAction, they all will call it and perform the same code
2) In the method were all the buttons are registered (cf: 1) it is possible to sort the buttons by subclassing the UIButton class, giving an enum value that represents what the button should perform and then in the called method check the enum value with a switch in order to trigger the wanted behavior
The UIBarButtonItem already has this tag property so you could use them by giving a value to each of your UIBarButtonItem in the Interface Builder and set them to call the following method
- (IBAction) myButtonsMethod:(id)object
if ([object isKindOfClass:[UIBarButtonItem class]])
{
switch ([(UIBarButtonItem *)object tag])
{
case myFirstTagValue
...
}
3) #Hermann Klecker solution is the right one.
I have a Button, Once the user submits a form the button image should change to DONE.PNG, or else it will remain as SUBMIT.PNG.
I need to know the following;
1.) How can we write a method, to know which button the user clicked. (If he clicked the button when it has the DONE.PNG or SUBMIT.PNG image on it)
my button click event is -(void)buttonClicked : (id)sender {}
Normally you would set the tag of the UIButton.
-Interface or storyboard you do it under the info about the UIButton element.
-Programatically you do it like this : myButton.tag = 23;
Then in the buttonClicked you do this:
UIButton* senderButton = (UIButton*) sender;
if(senderButton.tag==23) {
// It's the button as submit
// Set button image
senderButton.tag = 5;
}
if(senderButton.tag==5) {
// Button is done
}
Hope you get it working :)
As you are using a single button and changing its image only, then there are two simple ways that you can follow:
Check the name of image of the button if its DONE.PNG then do what is required and change the image else vis-versa.
Have a variable either you can take integer(it will help you if you have even more number of image changes on same button) to track button state/image.
For example we will typedef buttonState and check against it for suitable case.
In .h file
//Before interface declaration..
typedef enum
{
ButtonStateDone = 1,
ButtonStateSubmit,
//any other state that it may have.
} ButtonState
//in interface declaration..
ButtonState buttonState; //its a class level variable that we will use to track button state.
In .m file
Initially set buttonState as you show it on initial view. suppose button shows DONE.PNG
so buttonState = ButtonStateDone;
Now, in button action you will change this
if(buttonState == ButtonStateDone)
{
//do something and change button state.
}
if(buttonState == ButtonStateSubmit)
{
//do something and change button state.
}
Here, I used typedef, it is useful if you need to have more than 2 states for button else you can simply use a BOOL variable.
You can add a tag to the button i.e. NSInteger buttonTag = [sender tag] and then have conditional statements to check the tag values to determine which button was clicked.
can I assign same action to multiple buttons in the Interface Builder once they are all selected by one connection?
This problem is discussed in numerous threads but it isn't always just laid out simply. The easiest route is to create a function such as the one below. It takes the sender, in this case a UIButton, and gets the tag. You can then run whatever code you want based on that.
- (IBAction) buttonClick: (id) sender {
UIButton *button = (UIButton *)sender;
int row = button.tag;
NSLog(#"Button clicked: %i", row);
if (row == 1 ) {
// do something
}
}
In Interface Builder, attach the button to the function, and then use the Attributes Inspector to set the Tag value for each button, giving each one a different integer value.