DialogFragment中的Kotlin合成和自定义布局

Question

假设我有这样的布局:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<ImageButton
    android:id="@+id/add_dep_btn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentEnd="true"
    android:layout_alignParentRight="true"
    android:layout_marginEnd="5dp"
    android:layout_marginRight="5dp"
    android:src="@android:drawable/ic_input_add" />

<EditText
    android:id="@+id/add_dep_text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@id/add_dep_btn"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_alignTop="@id/add_dep_btn"
    android:layout_marginLeft="5dp"
    android:layout_marginStart="5dp"
    android:layout_toLeftOf="@id/add_dep_btn"
    android:layout_toStartOf="@id/add_dep_btn" />

<android.support.v7.widget.RecyclerView
    android:id="@+id/dep_list"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@id/add_dep_btn" />

<TextView
    android:id="@+id/empty_text"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@id/add_dep_text"
    android:layout_margin="20dp"
    android:gravity="center"
    android:text="@string/no_dep"
    android:textSize="22sp" />
</RelativeLayout>

我在DialogFragment中使用它:

class DepartmentChoiceDialog : DialogFragment() {
    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val builder = AlertDialog.Builder(activity)
        builder.setTitle(R.string.choose_or_create_dep)
            .setView(R.layout.department_chooser_dialog)
            .setNegativeButton(android.R.string.cancel, { d, i ->
                d.cancel()
            })
        return builder.create()
    }
}

如果我使用合成来引用小部件:

override fun onActivityCreated(savedInstanceState: Bundle?) {
    super.onActivityCreated(savedInstanceState)
    dep_list.layoutManager = LinearLayoutManager(activity)
    dep_list.itemAnimator = DefaultItemAnimator()
    dep_list.setHasFixedSize(true)
}

我在运行时遇到这个错误:

java.lang.NullPointerException:尝试在MyDialog上的空对象引用上调用虚拟方法'android.view.View android.view.View.findViewById(int)'._ $ _ findCachedViewById(DepartmentChoiceDialog.kt:0)

我不明白如何在DialogFragment案例中使用合成.它在Fragment和Activity中工作正常.

Answer 1

我发现了一种适用于自定义对话框的方法.

class ServerPickerDialogFragment: AppCompatDialogFragment() 
{
  // Save your custom view at the class level
  lateinit var customView: View;
  override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                            savedInstanceState: Bundle?): View? 
  {
       // Simply return the already inflated custom view
       return customView
  }

  override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
      // Inflate your view here
      customView = context!!.layoutInflater.inflate(R.layout.dialog_server_picker, null) 
      // Create Alert Dialog with your custom view
      return AlertDialog.Builder(context!!)
             .setTitle(R.string.server_picker_dialog_title)
             .setView(customView)
             .setNegativeButton(android.R.string.cancel, null)
             .create()
  }

  override fun onViewCreated(view: View, savedInstanceState: Bundle?) 
  {
    super.onViewCreated(view, savedInstanceState)
    // Perform remaining operations here. No null issues.
    rbgSelectType.setOnCheckedChangeListener({ _, checkedId ->
      if(checkedId == R.id.rbSelectFromList) {
             // XYZ
      } else {
             // ABC
      }
    })
  }
}

Answer 2

看起来默认情况下不支持此功能,但我发现最简单的方法就是这样.在基础对话框类中:

protected abstract val containerView: View

override fun getView() = containerView

在子类中:

override val containerView by unsafeLazy {
    View.inflate(context, R.layout.dialog_team_details, null) as ViewGroup
}

然后,您可以像往常一样使用合成视图,并将其containerView用作对话框的视图.

Answer 3

以前的答案不起作用，因为在使用 onCreateDialog 时不会调用 onViewCreated。您应该首先导入 kotlinx...department_chooser_dialog。查看.dep_list，然后按如下方式使用它：

import kotlinx.android.synthetic.main.department_chooser_dialog.view.dep_list
...
class DepartmentChoiceDialog : DialogFragment() {
    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val builder = AlertDialog.Builder(activity)
        val dialog = inflater.inflate(R.layout.department_chooser_dialog, null)
        dialog.dep_list.layoutManager = LinearLayoutManager(activity)
        dialog.dep_list.itemAnimator = DefaultItemAnimator()
        dialog.dep_list.setHasFixedSize(true)
        builder.setTitle(R.string.choose_or_create_dep)
               .setView(dialog)
                    ...

Answer 4

所以我不确定这个问题是否已经解决......我刚刚遇到这个问题。如果您有自定义对话框视图，请创建一个扩展 DialogFragment 的类，并使用“对话框”对象在布局中导入视图。在撰写本文时，我正在使用Android Studio 3.1.3and 。Kotlin version 1.2.41

import kotlinx.android.synthetic.main.your_custom_layout.*

class SelectCountryBottomSheet : BottomSheetDialogFragment() {

  override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
      val dialog = super.onCreateDialog(savedInstanceState) as BottomSheetDialog
      dialog.setContentView(R.layout.your_custom_layout)
      dialog.some_custom_close_button.setOnClickListener { dismiss() }
      return dialog
  }
}

Answer 5

将代码从onActivityCreated方法移至onViewCreated方法。像这样：

import kotlinx.android.synthetic.main.department_chooser_dialog.dep_list

override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    dep_list.apply {
        layoutManager = LinearLayoutManager(activity)
        itemAnimator = DefaultItemAnimator()
        setHasFixedSize(true)
    }
}

实际上我没有更深入地研究生成的代码，也许存在错误。