什么是最好的方法来做一个UIButton复选框？ [英] What is the best way to make a UIButton checkbox?

问题描述

我想从 UIButton 为我的iPhone应用程式建立标准复选框，标题和图片。

I am trying to make a standard check box for my iPhone app from a UIButton with a title and image. The button image changes between an "unchecked" image and a "checked" image.

开始时我尝试子类化 UIButton 但是 UIButton 没有 -init *** 方法用于 -init 方法。

At first I tried subclassing UIButton but UIButton has no -init*** method to use in my -init method.

这是最好的方法是什么？

What is the best way to do this?

。

推荐答案

您不应该需要继承 UIButton 类。根据设计，Objective-C优先于继承。

You shouldn't need to subclass the UIButton class. By design, Objective-C favors composition over inheritance.

UIButton 是 UIControl ，它有一个选择的属性。您可以使用此属性来切换复选框的打开/关闭行为，与 UISwitch 相同。

UIButton is a subclass of UIControl, which has a selected property. You can use this property to toggle the on/off behaviour of a checkbox, just the same way a UISwitch does.

您可以将一个操作附加到按钮的内部触发事件，并执行切换在那里，像这样：

You can attach an action to the button's touched up inside event, and perform the toggling in there, something like this:

// when you setup your button, set an image for the selected and normal states
[myCheckBoxButton setImage:nonCheckedImage forState:UIControlStateSelected];
[myCheckBoxButton setImage:nonCheckedImage forState:UIControlStateNormal];

- (void)myCheckboxToggle:(id)sender
{
    myCheckboxButton.selected = !myCheckboxButton.selected; // toggle the selected property, just a simple BOOL
}

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