手动设置“文本"对于 UITextField 不调用 .EditingChanged [英] Manually setting "text" for a UITextField does not call .EditingChanged

问题描述

我已经继承了具有目标的 UITextField

I have subclassed UITextField which has the target

self.addTarget(self, action: "onChange:", forControlEvents: .EditingChanged)

当用户在文本字段中输入时，这可以正常工作.尽管我需要在手动更新文本字段的text"属性时调用相同的方法onChange:".

This works fine when the user is typing in the textfield. Although I would need to the same method "onChange:" to be called when the textfield's "text" property is manually updated.

let tf = CustomTextField()
tf.text = "Trigger !!!"

我怎么能这样做?

推荐答案

这是故意的，如果您需要在事件处理程序中以编程方式更改文本，可以防止无休止的回声.

This is intentional, to prevent endless echo if you need to change the text programmatically in an event handler.

使用 sendActions(for controlEvents:) 手动通知事件处理程序.

Use sendActions(for controlEvents:) to manually notify event handlers.

tf.text = "Trigger !!!"
tf.sendActions(for: .editingChanged)

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