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。

早期的一个解决方案几乎起作用了。我尝试了一些稍微不同的方法，结果对我有用。

(一定要看他的解决方案) 这就是他的解决办法。点击这里 除了builder.getContext(). gettheme (). applystyle (R.style。Theme_Window_NoMinWidth,真正的);

我把它改成

 @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {


        // Use the Builder class for convenient dialog construction
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

        // Get layout inflater
        LayoutInflater layoutInflater = getActivity().getLayoutInflater();

        // Set layout by setting view that is returned from inflating the XML layout
        builder.setView(layoutInflater.inflate(R.layout.dialog_window_layout, null));


        AlertDialog dialog = builder.create();

        dialog.getContext().setTheme(R.style.Theme_Window_NoMinWidth);

最后一行是真正的不同之处。

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>

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();
    

}

要获得一个几乎覆盖整个屏幕的Dialog:首先定义一个ScreenParameter类

public class ScreenParameters
{
    public static int Width;
    public static  int Height;

    public ScreenParameters()
    {
        LayoutParams l = new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT);
        Width= l.width;
        Height = l.height;
    }
}

然后你必须在getDialog.getWindow().setLayout()方法之前调用screenparameter

@Override
public void onResume()
{
    super.onResume();
    ScreenParameters s = new ScreenParameters();
    getDialog().getWindow().setLayout(s.Width , s.Height);
}

@Override
public void onStart() {
    super.onStart();
    Dialog dialog = getDialog();
    if (dialog != null)
    {
        dialog.getWindow().setLayout(-1, -2);
        dialog.getWindow().getAttributes().windowAnimations = R.style.DialogAnimation;
        Window window = getDialog().getWindow();
        WindowManager.LayoutParams params = window.getAttributes();
        params.dimAmount = 1.0f;
        window.setAttributes(params);
        window.setBackgroundDrawableResource(android.R.color.transparent);
    }
}