我在Kotlin中有一个数组列表,我想要将它里面的所有项目都移除,让它变成一个空数组以开始添加新的动态数据。我尝试过 ArrayList.remove(index)
和 arrayList.drop(index)
,但都不起作用。
声明:
var fromAutoCompleteArray: List<String> = ArrayList()
这是我尝试的方法:
for (item in fromAutoCompleteArray){
fromAutoCompleteArray.remove(0)
}
我正在使用addTextChangedListener
来根据用户的输入删除旧数据并添加新数据。 private fun settingToAutoComplete() {
val toAutoCompleteTextView: AutoCompleteTextView =
findViewById<AutoCompleteTextView>(R.id.toAutoCompleteText)
toAutoCompleteTextView.addTextChangedListener(object : TextWatcher {
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
}
override fun afterTextChanged(s: Editable?) {
doLocationSearch(toAutoCompleteTextView.text.toString(), 2)
}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
toAutoCompleteTextView.postDelayed({
toAutoCompleteTextView.showDropDown()
}, 10)
}
})
val adapter = ArrayAdapter(this, android.R.layout.select_dialog_item, toAutoCompleteArray)
toAutoCompleteTextView.setAdapter(adapter)
toAutoCompleteTextView.postDelayed({
toAutoCompleteTextView.setText("")
toAutoCompleteTextView.showDropDown()
}, 10)
}
这里是添加数据的函数:
private fun doLocationSearch(keyword: String, fromTo: Number) {
val baseURL = "api.tomtom.com"
val versionNumber = 2
val apiKey = "******************"
val url =
"https://$baseURL/search/$versionNumber/search/$keyword.json?key=$apiKey"
val client = OkHttpClient()
val request = Request.Builder().url(url).build()
client.newCall(request).enqueue(object : Callback {
override fun onResponse(call: Call, response: okhttp3.Response) {
val body = response.body?.string()
println("new response is : $body")
val gson = GsonBuilder().create()
val theFeed = gson.fromJson(body, TheFeed::class.java)
if (theFeed.results != null) {
for (item in theFeed.results) {
println("result address ${item.address.freeformAddress} ")
if (fromTo == 1) {
fromAutoCompleteArray = fromAutoCompleteArray + item.address.freeformAddress
println(fromAutoCompleteArray.size)
} else {
toAutoCompleteArray = toAutoCompleteArray + item.address.freeformAddress
}
}
} else {
println("No Locations found")
}
}
override fun onFailure(call: Call, e: IOException) {
println("Failed to get the data!!")
}
})
}
你看到的这行代码 println(fromAutoCompleteArray.size)
展示了是否已删除,它总是在增加。
此外,我尝试使用 clear()
函数但没有循环都不起作用:
fromAutoCompleteArray.clear()