customBtn = [UIButton buttonWithType:UIButtonTypeCustom];
[customBtn setFrame:CGRectMake(200,200,68,68)];
UIImage *btnImage = [UIImage imageNamed:#"dash_pulsante_attivo"];
[customBtn setImage:btnImage forState:UIControlStateNormal];
[customBtn addTarget:self action:#selector(triggerMeasurement) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:customBtn];
I'm building a custom button that should be using a 68x68 png for it's normal state.
But the image looks deformed: it should be a circle, but it display as an oval.
Any hint or suggestion why it is happening? Curiously, I've tried to swap with another circular png, 220x220, and everything works as expected.
I hope this error happened, because of image size, check whether the image size is 68x68.
nothing wrong in your code.
check the image "dash_pulsante_attivo" resolution. If it's less than 68*68 it supposed to get distorted. Higher resolution won't have distortion problem.
If you want resize your image programatically. You can do like this.
I know there is three20 solution. But I don't want to use three20 just for that purpose. So programmingly, is there a solution for that?
Yes there is a solution. You can use the regular expression to detect particular kind of strings on touches began of the label and then based on the regular expression which matches the string you can perform the action.
So if you want to do that, you need to subclass the UILabel and overwrite the Touch methods for the label.
Hope this helps you.
There is one of the Label's called OHAttributedLabel which does similar function. And here is a fork, that supports ARC.
You can use a UIButton with the button type as UIButtonTypeCustom, on the button click you can call the url.
UIButton *urlButton = [UIButton buttonWithType:UIButtonTypeCustom];
urlButton.frame = CGRectMake(10, 10, 80, 30);
[urlButton setTitle:#"Click Here" forState:UIControlStateNormal];
[urlButton addTarget:self action:#selector(urlButtonClicked) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:urlButton];
I'm losing my mind over this one. I have UIButton connected as Outlet. I want to change it's image. In the viewDidLoad function, I try to set the image like so:
[button1 setImage:[UIImage imageNamed:#"house.png"] forState:UIControlStateNormal];
Nothing happens. However, if I use ImagePicker, it somehow works. In the ImagePickers function "didFinishPickingImage", I repeat the exactly same command as above for setting image and it works, the image is displayed normally.
I've been thinking that maybe the button's image is not refreshing itself, but trying to call [button1 setNeedsDisplay], or [button1.imageView setNeedsDisplay] or even [button1.imageView.image setNeedsDisplay] does nothing.
Does anyone have any idea about this? I've wasted two hours by now and I'm really getting frustrated, because I'm certain that the reason must be so stupid it's unbelivable.
Please check your button type.
If your button type is "System" you should change it to "Custom"
Two things to do here:
#1, change your code to:
[button1 setImage:[UIImage imageNamed:#"house.png"] forState:UIControlStateNormal];
and #2
make sure your UIImage returns a valid image.
In other words,
UIImage * imageToSet = [UIImage imageNamed: #"house.png"];
if(imageToSet)
{
[button1 setImage:[UIImage imageNamed:#"house.png"] forState:UIControlStateNormal];
} else {
// if you see this line in your console, then you know where to look for a problem
NSLog( #"why is my image object nil?");
}
For anyone who will find themselves in a similar situation; I was using the mentioned button inside a custom cell for table view. However, the cells aren't loaded right away (i.e. inside viewDidLoad/viewWillAppear etc.), but inside the tableView:cellForRowAtIndexPath function. All my button variables were nil at that point. My solution was to load the image after the cell has been created and it has worked straight away afterwards.
Here are a couple additional notes. UIButton setImage: forState: is the correct method:
[button1 setImage:[UIImage imageNamed:#"house.png"] forState:UIControlStateNormal];
imageNamed is a great convenience method for grabbing the image, but make sure it returns an object. Forgetting to include the image file in the current target gets me all of the time.
[UIImage imageNamed:#"house.png"]
You also don't need the extension. The SDK works this out.
[UIImage imageNamed:#"house"]
And even though UIControlState is a bit mask, you cannot OR the values together. This does not not not work and I must must must remember this because it gets me every time I use the call.
// NO NO NO
[button1 setImage:[UIImage imageNamed:#"house"] forState:UIControlStateNormal|UIControlStateSelected];
// YES
[button1 setImage:[UIImage imageNamed:#"house"] forState:UIControlStateNormal];
[button1 setImage:[UIImage imageNamed:#"house"] forState:UIControlStateSelected];
Was getting the same problem when UIbutton was in UITableViewCell.
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:[UIImage imageNamed:#"detail.png"] forState:UIControlStateNormal];
should work in UITableViewCell
Glad to know that the problem is solved but none of the answers actually addresses the problem.
Generally, if the code is correct, then the error shifts from "syntax error" to the "logical error" category. There is no definite guide to handle it but here is a small checklist that can help anyone to troubleshoot their code.
1) The IBOutlet is not connected or renamed.
2) Make sure that the UIButton type is custom.
3) The image is set (more than once), somewhere else in the code.
4) You are trying to set the Image through any sync method which is not using the main thread. (There are several threads on that alone).
5) If you are nesting the images as subviews, make sure the problem isn't with their parent view.
6) If it is appearing in Simulator but not in the device, It's a lettercase (Uppercase, lowercase difference in the code and the filename.
7) Modern simulators works with very low GPU memory on older machines. You can tweak the simlator options to make it appear. E.g (Command + Right Arrow) twice to change the simulator orientation and your changes will appear.
There are few other but common pitfalls where developers usually overlook
1) The image doesn't exist OR you are making a spelling mistake.
2) The filetype is different than mentioned. (JPG, PNG).
Last thing you'll want to check - make sure you're setting the image on the main thread! Just ran into an issue where I was setting a button image in a callback from ALAssetLibrary (fetching images from photo library). The image wouldn't update until I tapped the button. Turns out the callback was happening off main...
for those having issues with system images not appearing, just use systemName: instead of named
if let starImg = UIImage(systemName: "star.fill") {
button.setImage(starImg, for: .normal)
}
It's for ios13 and later...
For me it was to move the line:
[button1 setImage:[UIImage imageNamed:#"house.png"] forState:UIControlStateNormal];
from awakeFromNib method
to viewDidLoad method
I guess,
don't create like this
UIButton *nextButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
by this create method ,UIButton is create by use default type,so your background image is not work.
try this,
UIButton *nextButton = [[UIButton alloc] initWithFrame:CGRectMake(9, 154, 300, 48)];
or other,except buttonWithType
This is happening because the state of the Button doesn't stays selected once clicked by default.
I solved it by making an IBaction on that button click and toggling the selected state.
-(IBAction) checkButtonClicked:(id)sender{
checkButton.selected = !checkButton.selected;
}
In my case, it is drawn by custom animation code and not set by the image, so it doesn't work by setting any image, it has to change the animation code.
With images, you have to import them into the project not as references but as copies. So when you go to add files to project, choose "Create groups" instead of "Create folder references". Also make sure "Copy items if needed" is checked.
This is confusing because importing as references works when you are using images as textures (e.g. for Sprites). However, it doesn't work when you want to use images for buttons (e.g. for using image name in [UIImage imageNamed:#"house.png"]
I faced this same issue of the image not being shown on the UIButton.
I had to change this line -
myButton.setImage(<my_UIImage_object>, for: [.normal, .focused])
to this -
myButton.setImage(<my_UIImage_object>, for: .normal)
I have a situation I'm trying to change background image of 4 buttons like this:
if(some condition){
[firstSeverityButton setBackgroundImage:[UIImage imageNamed:#"greySeverity.jpg"] forState:UIControlStateDisabled];
[secondSeverityButton setBackgroundImage:[UIImage imageNamed:#"greySeverity.jpg"] forState:UIControlStateNormal];
[thirdSeverityButton setBackgroundImage:[UIImage imageNamed:#"greySeverity.jpg"] forState:UIControlStateNormal];
[fourthSeverityButton setBackgroundImage:[UIImage imageNamed:#"greySeverity.jpg"] forState:UIControlStateNormal];
[fifthSeverityButton setBackgroundImage:[UIImage imageNamed:#"redSeverity.png"] forState:UIControlStateNormal];
}
But the background of the other four disappears when I touch any one
Please enlighten me on this how can his be tackled.
May be you are looking for the radiobutton, You can write down a custom class for radio button and make things work out easily.
[firstSeverityButton setBackgroundImage:[UIImage imageNamed:#"greySeverity.jpg"] forState:UIControlStateDisabled];
This code actually works fine, with every control state. I think the problem is with the initial image for the button and the current button state (in both nib and code).
The state of buttons can be changed with:
button.enabled=yes;
button.highlighted = NO;
button.selected = NO;
When you setup image for control state specifically, the change on image appear on that specific control state. So the change depends on both the initial image and the current control state of button
NOTE: We are applying change on the background image. There is an image property for the button which can actually hide the changes of background image. If you setup the image
[firstSeverityButton setImage:[UIImage imageNamed:#"greySeverity.jpg"] forState:UIControlStateDisabled];
anywhere in code and maybe it can hide your background image setting.
Also there is a possibility of error in your if-else loop ...go through the loops and verify every conditions whether the images get set properly.
How to make a UIImageView open a URL in Safari when user clicks it?
I would suggest using a button for this purpose instead. You can create a custom UIButton with whatever image you want. This gives the advantage of providing the built-in target-action mechanism of a button, as well as being able to provided a highlighted image to provide the user feedback. Consider using something like this:
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:[UIImage imageNamed:#"regular_image.png"] forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:#"highlighted_image.png"] forState:UIControlStateHighlighted];
[button addTarget:self action:#selector(loadURL) forControlEvents:UIControlEventTouchUpInside];
Note that it will still look like "just an image" to the user.