杨晓彬 yangxiaobinhaoshuai

Kotlin 协程实现原理

从一个例子开始

fun main() {
    postItem(Item("item"))
}

fun postItem(item: Item) {

People

	When a user interacts with a UI element the various listeners are called in a top down order. (For example: OnTouch -> OnFocusChange -> OnClick.) If a listener has been defined (with setOn...Listener) and it consumes this event: the lower priority listeners will not be called. By its nature the first time you touch an EditText it receives focus with OnFocusChangeListener so that the user can type. The action is consumed here therefor OnClick is not called. Each successive touch doesn't change the focus so the event trickles down to the OnClickListener.

	Basically, you have three choices:

	Set the focusable attribute to false in your XML:

	android:focusable="false"
	Now the OnClickListener will fire every time it is clicked. But this makes the EditText useless since the user can no longer enter any text...

	Implement an OnFocusChangeListener along with the OnClickListener: