localChatManager.addIncomingListener { from, message, chat ->
Log.v(TAG,"listener")
//You can't modify views from non-UI thread.
this@chatActivity.runOnUiThread { object :Runnable{
override fun run() {
Log.i(TAG,"runOnUiThread")
}
} }
}
我不明白为什么runOnUiThread不起作用，但在这种方法之外，一切都正常.
您要做的是将lambda传递给runOnUiThread函数.它将运行该lambda，并创建一个继承自Runnable的object，然后对其不做任何处理.如果您将其格式化为这样(添加了一些额外的日志(log)语句和解释)，也许您可以更好地看到这一点:
runOnUiThread({
Log.i(TAG, "This is run")
object : Runnable { // This whole expression
override fun run() { // returns an object which
Log.i(TAG, "runOnUiThread") // is a Runnable, but does
} // not at any point invoke
} // its "run" method
Log.i(TAG, "And so is this")
})
The created object is not assigned to a variable, and is never used. If you want to pass in a Runnable instance to the runOnUiThread method, you can do that by just putting it inside the parentheses of the runOnUiThread call:
runOnUiThread(
object : Runnable {
override fun run() {
Log.i(TAG, "runOnUiThread")
}
}
)
使用runOnUiThread的最简单方法是使用SAM转换将lambda传递给它，并直接在其中编写要执行的代码.
runOnUiThread {
Log.i(TAG, "runOnUiThread")
}
下面是official documentation covering SAM conversions，它在示例中恰好使用了Runnable.