无法更改UIButton的大小

Question

This seems such a simple thing, I can't understand why it's going wrong. I'm trying to change the size of a UIButton from the touchUpInside handler of another. To repro, I've created a new (iOS 6) project in Xcode, and dragged two buttons to the xib file that's created by default. The touchUpInside handler for button1 is shown below. If I just include the statement that sets the origin.x of button2 , I see button2 move as expected. However, the statement that sets the size.width of the button doesn't work. In fact, if I include that statement the origin doesn't change either.

I can resize the button fine in the xib designer and the only property I've set (other than

- (IBAction)buttonPressed:(id)sender {
    CGRect f = self.button2.frame;
    f.origin.x += 10;
    // this doesn't work, including it prevents even the origin change from working
    f.size.width += 10; 
    self.button2.frame = f;
}

How can I successfully change the size of the button?

Thanks!

Answer 1

For sure you are using AutoLayout, simply what happen here is iOS AutoLayout mechanism tries to set your layout automatically. try your code by turning off AutoLayout. hope you know how to turn off the auto layout in xcode, if not let me know.

Happy coding!!!

EDIT:

AutoLayout comes with iOS 6, thats why your code worked with older version(iOS 5). btw as Nick said you can turn off AutoLayout in the file inspector in the xcode.

See attached screenshot.

Answer 2

Try :

CGRect buttonFrame = button.frame;
buttonFrame.size = CGSizeMake(150, 70);
button.frame = buttonFrame;

Answer 3

Work with the bounds:

[self.button setBounds:CGRectMake(0, 0, 400, 400)];

Works whether or not auto layout is on! As always, make sure your Outlet is properly set up so that you can talk to the button.

You could do this in auto layout as well. Remove the width and height constraints and add in the new ones, but if you don't have a width or height constraint on your button (probably wise) then just set the bounds and unless you need to reposition your button it should just work as auto layout will automatically update the constraints when you change the buttons bounds.

BTW, you should never be touching a buttons frame unless you're using it to position the object in a manual way. Bounds are for sizing, frame is for positioning.

Answer 4

Disabling the auto-layout may not be the solution you want.

One possibility is that you set the button attributed title before and now just changing the title font size won't work. You need to setAttributedTitle again

Answer 5

If you are trying to change a UIButton text length, you will be restricted by the default length and when it is too long a line break will be implemented (ie Truncate Tail or three dots). Change the default size by:

yourButton.setTitle("yourString", for: UIControlState.normal)

This will work for most cases but not all UIControlState s