你可以用百分比表示宽度。

<style name="Theme.Holo.Dialog.MinWidth">
<item name="android:windowMinWidthMajor">70%</item>

在这个例子中，我使用了Holo Theme。

public void onResume() {

    Window window = Objects.requireNonNull(getDialog()).getWindow();
    Point size = new Point();
    assert window != null;
    Display display = window.getWindowManager().getDefaultDisplay();
    display.getSize(size);
    window.setLayout( (int)(size.x * 0.9), (int) (size.y * 0.75));
    window.setGravity( Gravity.CENTER );
    super.onResume();
    

}

我把@rmirabella的回答也更新了一下，让它也能处理身高问题:

private fun DialogFragment.setSize(widthPercentage: Int, heightPercentage: Int) {
    val newWidth = widthPercentage.toFloat() / 100
    val newHeight = heightPercentage.toFloat() / 100
    val dm = Resources.getSystem().displayMetrics
    val rect = dm.run { Rect(0, 0, widthPixels, heightPixels) }
    val percentWidth = rect.width() * newWidth
    val percentHeight = rect.height() * newHeight
    dialog?.window?.setLayout(percentWidth.toInt(), percentHeight.toInt())
}

然后在你的DialogFragment中或onStart()之后:

override fun onStart() {
    super.onStart()
    setSize(
        widthPercentage = 100,
        heightPercentage = 80
    )
}

Working on Android 6.0, ran into the same issue. AlertDialog would default to predefined width set in the theme regardless of the actual width set in the custom view's root Layout. I was able to get it to set properly adjusting the width of the loading_message TextView. Without investigating further, it seems that sizing the actual elements and having the root Layout wrap around them makes it work as expected. Below is an XML layout of a loading dialog which sets width of the the dialog correctly. Using the this library for the animation.

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@color/custom_color"
    android:padding="@dimen/custom_dimen">
    <com.github.rahatarmanahmed.cpv.CircularProgressView
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/progress_view"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:layout_centerHorizontal="true"
        app:cpv_color="@color/white"
        app:cpv_animAutostart="true"
        app:cpv_indeterminate="true" />
    <TextView
        android:id="@+id/loading_message"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:layout_below="@+id/progress_view"
        android:layout_centerHorizontal="true"
        android:gravity="center"
        android:textSize="18dp"
        android:layout_marginTop="@dimen/custom_dimen"
        android:textColor="@color/white"
        android:text="@string/custom_string"/>
</RelativeLayout>

我修复了它设置根元素布局参数。

int width = activity.getResources().getDisplayMetrics().widthPixels;
int height = activity.getResources().getDisplayMetrics().heightPixels;
content.setLayoutParams(new LinearLayout.LayoutParams(width, height));

下面是在xml中设置DialogFragment宽度/高度的方法。只需要用一个透明背景的框架布局(任何布局都可以)来包装你的viewherarchy。

透明背景似乎是一个特殊的标志，因为当你这样做时，它会自动将framayout的子元素居中。您仍然会在您的片段后面看到全屏变暗，这表明您的片段是活动元素。

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/transparent">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:background="@color/background_material_light">

      .....