setImage：forState不适用于UIButton的子类

Question

I create a class RadioButton that inherited from UIButton ,and rewrite the method layoutSubViews where reset the frame of self.imageView and self.titleLabel ,when I call the method setImage:forState: of RadioButton instance,it does not work, but the method radioButton.imageView.image = [UIImage imageNamed:@""] work. It is an interesting problem ,I appreciate so much if anyone know why and share the reason .

Answer 1

When we set title,image for button we need to use below code

For Button

[button setTitle:@"Your Title" forState:UIControlStateNormal];

For Image

[button setImage:[UIImage imageNamed:@"Your Image Name"] forState:UIControlStateNormal];

why should not we use titleLabel

Do not use the label object to set the text color or the shadow color. Instead, use the setTitleColor:forState: and setTitleShadowColor:forState: methods of this class to make those changes.

The titleLabel property returns a value even if the button has not been displayed yet. The value of the property is nil for system buttons.

why should we use setTitle

Use this method to set the title for the button. The title you specify derives its formatting from the button's associated label object. If you set both a title and an attributed title for the button, the button prefers the use of the attributed title over this one.

At a minimum, you should set the value for the normal state. If a title is not specified for a state, the default behavior is to use the title associated with the UIControlStateNormal state. If the value for UIControlStateNormal is not set, then the property defaults to a system value.

For Image