小编Zor*_*gan的帖子

我实现了一个ArrayAdapter以填充我的Spinner观点。的Spinner工作正常，但是当我单击微调器中的项目时，android并未检测到。

我所有的要求遵守微调例如在Android文档 包括实施AdapterView.OnItemSelectedListener我的活动，并覆盖它的两个方法OnItemSelectedListener和onNothingSelected，但是，没有我的Log那些方法报表打印，使他们不被调用。

我还通过将监听器设置为微调器choose_user.onItemSelectedListener = this@PlayerDetails。

这是我的活动：

class PlayerDetails : AppCompatActivity(), View.OnClickListener, TextWatcher, AdapterView.OnItemSelectedListener {
    val TAG: String = "PlayerDetails"
    val FirebaseTAG: String = "FirebaseDebug"

    var numOfPlayers: Int = 1
    var currentPlayer: Int = 1

    var name: String = ""
    var age: Int = 0
    var genderId: Int = 0
    var genderResult: String = ""

    val db = FirebaseFirestore.getInstance()
    var users: MutableList<String> = …

这是我的房间实体：

@Entity(tableName = "matched_users")
data class MatchedUser(
    @PrimaryKey(autoGenerate = true) val id: Int,
    @ColumnInfo(name = "match_id") val matchId: String
)

这是我在我的片段中实例化它：

private fun pass(){
    CoroutineScope(coroutineContext).launch {
            val match = MatchedUser()
       CustomApplication.database?.matchedUsersDao()?.addMatchUid(match)
            Log.d(TAG, "Added matchId to DB")
        }
    return removeUser2()
}

当我将鼠标悬停在上面时，MatchedUser()它仍然说我需要传递 .. 的参数id，但它应该按照实体中的说明自动生成。

知道为什么吗？

我正在使用 Firebase Cloud Messaging 在我的应用中接收数据：

class CustomFirebaseMessagingService : FirebaseMessagingService() {

    override fun onMessageReceived(msg: RemoteMessage?) {
        val data = msg?.data ?: return
        val name = data["name"] as String
        val age = data["age"]?.toIntOrNull() ?: return
        val bio = data["bio"] as String
        val img1 = data["img1"] as String
        val match = Profile(name, age, bio, img1, null, null)
        Log.d(TAG, "onMessageReceived(): $name is $age")
        val fcmViewModel = ViewModelProviders.of(this).get(FcmViewModel::class.java) // .of() only takes a fragment/activity
        FcmViewModel().match.postValue(match)
        Log.d(TAG, "Value: " + FcmViewModel().match.value.toString()) // null
        super.onMessageReceived(msg)
    }

当我收到 …

我正在关注Facebook针对Android SDK的登录教程，login_button.setReadPermissions()现在似乎已弃用：

我用什么代替？

我创建了一个扩展DialogFragment()：

class AlertDialogFragment(context: Context, 
                          val positiveButtonText: String, 
                          val positiveButtonListener: DialogInterface.OnClickListener,
                          val negativeButtonText: String, 
                          val negativeButtonListener: DialogInterface.OnClickListener,  
                          neutralButtonText: String, 
                          neutralButtonListener: DialogInterface.OnClickListener
                          ) : DialogFragment() {

但是我希望最后两个参数是可选的。

我怎样才能做到这一点？

我无法设置，neutralButtonListener: DialogInterface.OnClickListener = null因为DialogInterface.OnClickListener是非空类型。

我收到以下错误：No exact matches in call to initializer在我的@AppStorage 上下面的变量上：

模型.swift

class UserSettings: ObservableObject {
    @AppStorage("minAge") var minAge: Float = UserDefaults.standard.float(forKey: "minAge") 

此变量旨在绑定到Slider下面的值。

设置.swift

import SwiftUI
struct Settings: View {
    let auth: UserAuth
    init(auth: UserAuth) {
        self.auth = auth
    }
    @State var minAge = UserSettings().minAge
    let settings = UserSettings()

    var body: some View {
            VStack {
                NavigationView {
                    Form {
                        Section {
                        Text("Min age")
                        Slider(value: $minAge, in: 18...99, step: 1, label: {Text("Label")})
                            .onReceive([self.minAge].publisher.first()) { (value) in …

尝试celery -A draft1 beat在终端上执行时出现此错误。

Traceback (most recent call last):
  File "/home/james/postr/env/lib/python3.5/site-packages/celery/apps/beat.py", line 107, in start_scheduler
    service.start()
  File "/home/james/postr/env/lib/python3.5/site-packages/celery/beat.py", line 558, in start
    interval = self.scheduler.tick()
  File "/home/james/postr/env/lib/python3.5/site-packages/celery/beat.py", line 279, in tick
    self.apply_entry(entry, producer=self.producer)
  File "/home/james/postr/env/lib/python3.5/site-packages/kombu/utils/objects.py", line 44, in __get__
    value = obj.__dict__[self.__name__] = self.__get(obj)
  File "/home/james/postr/env/lib/python3.5/site-packages/celery/beat.py", line 411, in producer
    return self.Producer(self._ensure_connected(), auto_declare=False)
  File "/home/james/postr/env/lib/python3.5/site-packages/celery/beat.py", line 395, in _ensure_connected
    _error_handler, self.app.conf.broker_connection_max_retries
  File "/home/james/postr/env/lib/python3.5/site-packages/kombu/connection.py", line 405, in ensure_connection
    callback)
  File "/home/james/postr/env/lib/python3.5/site-packages/kombu/utils/functional.py", line 333, in retry_over_time
    return fun(*args, **kwargs)
  File …

我正在使用androidx Preferences library来实现我的设置。

然而不幸的是，Android 没有RangeBar2 个拇指，只有SeekBarPreference1 个拇指。

创建我自己的最好的简单方法是什么RangeBar？我尝试了多个库，例如：https : //github.com/nickwinder/range-bar-preference和https://android-arsenal.com/details/1/1756，但它们根本无法编译。

对于上下文，我试图创建一个RangeBar介于 1 和 99 之间的值，其中包括最小值和最大值。

<androidx.preference.PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <Preference
       android:title="Settings"
       android:key="settings_category"
       android:layout="@layout/preference_title"/>
    <SeekBarPreference
        android:layout="@layout/preference_widget_seekbar_override"
        app:showSeekBarValue="false"
        android:max="30"
        android:defaultValue="10"
        android:key="distance"
        android:title="Max distance (km)"/>

    <RangeBarPreference
        .../>

在 Kotlin/Android 活动/片段中定义全局变量的最佳方法是什么？

当您应该使用这 2 种方法来定义全局变量时，有哪些不同的场景：

var viewpager: CustomViewPager? = null 

或者

lateinit var viewpager: CustomViewPager

?

如果我使用前者，我将不必在我的代码中检查 null。例如，如果我用于lateinit以下内容：

viewpager = activity?.findViewById<CustomViewPager>(R.id.viewpager) 那么我将不得不检查空值。

当我尝试pod init在 Xcode 项目目录中执行时，它返回以下内容：

Traceback (most recent call last):
    35: from /usr/local/bin/pod:23:in `<main>'
    34: from /usr/local/bin/pod:23:in `load'
    33: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.2/bin/pod:36:in `<top (required)>'
    32: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    31: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    30: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.2/lib/cocoapods.rb:8:in `<top (required)>'
    29: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    28: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    27: from /Library/Ruby/Gems/2.6.0/gems/activesupport-4.2.11.3/lib/active_support/core_ext/string/inflections.rb:1:in `<top (required)>'
    26: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    25: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    24: from /Library/Ruby/Gems/2.6.0/gems/activesupport-4.2.11.3/lib/active_support/inflector/methods.rb:3:in `<top (required)>'
    23: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    22: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    21: from /Library/Ruby/Gems/2.6.0/gems/activesupport-4.2.11.3/lib/active_support/inflections.rb:1:in `<top (required)>'
    20: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require' …