如何使用 Compose 内容配置 DialogFragment 的宽度？

Question

在我的 Android 应用程序中，“关于”屏幕设置为对话框，如下所述：

class AboutDialog : DialogFragment() {

    // ...   

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View = inflater.inflate(R.layout.about_dialog, container, false).apply {
        findViewById<ComposeView>(R.id.about_view).apply {
            setViewCompositionStrategy(DisposeOnViewTreeLifecycleDestroyed)
            setContent {
                AboutScreen()
            }
            isClickable = true
        }
    }

}

...

about_dialog.xml

:

<?xml version="1.0" encoding="utf-8"?>
<androidx.compose.ui.platform.ComposeView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/about_view"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

...

AboutScreen

可组合项：

@Composable
fun AboutScreen {
    MyTheme {
        Scaffold { contentPadding ->
            Box(
                Modifier
                    .padding(contentPadding)
                    .fillMaxSize()
                    .verticalScroll(rememberScrollState())
            ) {
                Column {
                    // ...
                }
            }
        }
    }
}

对话框（屏幕截图中的模糊部分）扩展到屏幕的一定百分比，以便背景屏幕在左侧和右侧可见。

如何配置对话框的宽度？

Answer 1

您可以使用以下。

class AboutDialog : DialogFragment() {

    // ...   

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View = inflater.inflate(R.layout.about_dialog, container, false).apply {
        //Sets the dialog width to targetWidth
        (dialog as ComponentDialog).apply {
              setOnShowListener {
                  val targetWidth = 400
                  window!!.attributes = window!!.attributes.apply {
                       width = targetWidth
                  }
              }
         }
        
        //rest of your codes
    }

}

编辑： 或者您可以为对话框设置自定义主题。这甚至会在显示对话框之前设置宽度。

//You need to extend AppCompatDialogFragment instead of DialogFragment
//to make the custom AppCompat theme work
class AboutDialog : AppCompatDialogFragment() {
      override fun onCreate(savedInstanceState: Bundle?) {
         //Apply custom theme
         setStyle(STYLE_NORMAL, R.style.Theme_CustomDialog)
         super.onCreate(savedInstanceState)

      }
 
     //rest of your codes
   

}

res/values/styles.xml

<resources>
  <style name="Theme.CustomDialog" parent="@style/ThemeOverlay.AppCompat.Dialog">
        <!--Portrait-->
        <item name="windowFixedWidthMinor">50%</item>
        <item name="windowFixedHeightMinor">50%</item>
        <item name="android:windowMinWidthMinor">50%</item>

        <!--Landscape-->
        <item name="windowFixedWidthMajor">50%</item>
        <item name="windowFixedHeightMajor">50%</item>
        <item name="android:windowMinWidthMajor">50%</item>

    </style>
</resources>