Android studio 如何知道线程何时完成执行
我正在Android studio中使用Kotlin做一个测验应用程序。我正在从一个API获取数据,并将其显示在活动中。现在我正在实现一个进度条,它指示回答每个问题的时间。这是我从API获取的函数:Android studio 如何知道线程何时完成执行,android-studio,kotlin,runnable,Android Studio,Kotlin,Runnable,我正在Android studio中使用Kotlin做一个测验应用程序。我正在从一个API获取数据,并将其显示在活动中。现在我正在实现一个进度条,它指示回答每个问题的时间。这是我从API获取的函数: private fun fetch(){ val theme = intent.getIntExtra("sport", 21) val difficulty = intent.getStringExtra("medium") val url = "https://op
private fun fetch(){
val theme = intent.getIntExtra("sport", 21)
val difficulty = intent.getStringExtra("medium")
val url = "https://opentdb.com/api.php?amount=10&category=21&difficulty=medium&type=multiple"
val request = Request.Builder()
.url(url)
.build()
client.newCall(request).enqueue(object: Callback {
override fun onResponse(call: Call, response: Response) {
val body = response.body?.string()
val gson = GsonBuilder().create()
val triviaRequest = gson.fromJson(body, TriviaRequest::class.java)
val result = triviaRequest.results[0]
val question = result.question.toSpanned()
val questionCategory = result.category.toSpanned()
val correctAnswer = result.correct_answer.toSpanned()
val incorrectAnswer1 = result.incorrect_answers[0].toSpanned()
val incorrectAnswer2 = result.incorrect_answers[1].toSpanned()
val incorrectAnswer3 = result.incorrect_answers[2].toSpanned()
val questions = listOf(
correctAnswer,
incorrectAnswer1,
incorrectAnswer2,
incorrectAnswer3
)
shuffle(questions)
runOnUiThread {
val button1 = findViewById<Button>(R.id.alternative1)
val button2 = findViewById<Button>(R.id.alternative2)
val button3 = findViewById<Button>(R.id.alternative3)
val button4 = findViewById<Button>(R.id.alternative4)
questionText.text = question
themeText.text = questionCategory
button1.text = questions[0]
button1.isEnabled = true
button2.text = questions[1]
button2.isEnabled = true
button3.text = questions[2]
button3.isEnabled = true
button4.text = questions[3]
button4.isEnabled = true
button1.setOnClickListener {
button1.isClickable = false
if (button1.text == correctAnswer) {
score += 1
fetch()
} else {
button1.text = "---"
}
}
button2.setOnClickListener {
button2.isClickable = false
if (button2.text == correctAnswer) {
score += 1
fetch()
} else {
button2.text = "---"
}
}
button3.setOnClickListener {
button3.isClickable = false
if (button3.text == correctAnswer) {
score += 1
fetch()
} else {
button3.text = "---"
}
}
button4.setOnClickListener {
button4.isClickable = false
if (button4.text == correctAnswer) {
score += 1
fetch()
} else {
button4.text = "---"
}
}
}
response.close()
}
override fun onFailure(call: Call, e: IOException) {
e.printStackTrace()
}
})
}
private fun fetch(){
val theme=intent.getIntExtra(“运动”,21)
val难度=intent.getStringExtra(“中等”)
val url=”https://opentdb.com/api.php?amount=10&category=21&difficulty=medium&type=multiple"
val request=request.Builder()
.url(url)
.build()
client.newCall(请求).enqueue(对象:回调{
覆盖fun onResponse(调用:调用,响应:响应){
val body=response.body?.string()
val gson=GsonBuilder().create()
val triviaRequest=gson.fromJson(正文,triviaRequest::class.java)
val结果=繁琐的请求。结果[0]
val question=result.question.tospan()
val questionCategory=result.category.tospan()
val correctAnswer=result.correct_answer.tospan()
val incorrectAnswer1=结果。回答不正确[0]。toSpanned()
val incorrectAnswer2=结果。回答不正确[1]。toSpanned()
val incorrectAnswer3=结果。回答不正确[2]。toSpanned()
val问题=列表(
回答正确,
不正确的答案1,
不正确的答案2,
不正确的答案3
)
洗牌(问题)
runOnUiThread{
val button1=findViewById(R.id.alternative1)
val按钮2=findViewById(R.id.alternative2)
val按钮3=findViewById(R.id.alternative3)
val按钮4=findViewById(R.id.alternative4)
questionText.text=问题
themeText.text=问题类别
button1.text=问题[0]
按钮1.isEnabled=真
按钮2.text=问题[1]
按钮2.isEnabled=真
button3.text=问题[2]
button3.isEnabled=true
按钮4.text=问题[3]
按钮4.isEnabled=真
button1.setOnClickListener{
button1.isClickable=false
如果(button1.text==correctAnswer){
分数+=1
fetch()
}否则{
button1.text=“--”
}
}
button2.setOnClickListener{
按钮2.isClickable=false
if(button2.text==correctAnswer){
分数+=1
fetch()
}否则{
button2.text=“--”
}
}
button3.setOnClickListener{
button3.isClickable=false
if(button3.text==correctAnswer){
分数+=1
fetch()
}否则{
button3.text=“--”
}
}
按钮4.setOnClickListener{
按钮4.isClickable=false
如果(按钮4.text==correctAnswer){
分数+=1
fetch()
}否则{
button4.text=“--”
}
}
}
答复:close()
}
覆盖失效(调用:调用,e:IOException){
e、 printStackTrace()
}
})
}
下面是我显示进度条的方式:
val fetch = runCatching { fetch() }
if(fetch.isSuccess) {
val handler = Handler()
Thread(Runnable {
while (progressCount < 100) {
progressCount += 1
try {
Thread.sleep(50)
} catch (e: InterruptedException) {
e.printStackTrace()
}
handler.post {
progressBar.progress = progressCount
}
}
}).start()
}
}
val fetch=runCatching{fetch()}
if(fetch.issucess){
val handler=handler()
线程(可运行{
而(进程计数<100){
progressCount+=1
试一试{
线程。睡眠(50)
}捕获(e:中断异常){
e、 printStackTrace()
}
handler.post{
progressBar.progress=progressCount
}
}
}).start()
}
}
现在的问题是,活动一开始,我的进度条就开始显示,但问题还没有出现。我的问题是,如何知道我的fetch函数何时完成执行?
这样我就可以显示进度条了
谢谢 您可以查看kotlin协程并使用挂起函数,也可以使用如下回调:
fun fetch (callback: ()->Unit) { // take callback param
... // do the stuff
callback() // call the callback on complete
}
fetch {
// Done fetching here, execute your code inside this
}