你可以下面的代码设置布局的宽度和高度从java。

final AlertDialog alertDialog  = alertDialogBuilder.create();
final WindowManager.LayoutParams WMLP = alertDialog.getWindow().getAttributes();

WMLP.gravity = Gravity.TOP;
WMLP.y = mActionBarHeight;
WMLP.x = getResources().getDimensionPixelSize(R.dimen.unknown_image_width);

alertDialog.getWindow().setAttributes(WMLP);
alertDialog.show();

在我的例子中，DialogFragment占用了完整的活动大小，就像一个Fragment一样。DialogFragment基于xml布局，而不是AlertDialog。我的错误在于将对话片段作为常规片段添加到FragmentManager中:

fragmentManager?.beginTransaction()?.run {
    replace(R.id.container, MyDialogFragment.newInstance(), MyDialogFragment.TAG)
    addToBackStack(MyDialogFragment.TAG)
}?.commitAllowingStateLoss()

相反，我需要显示对话片段:

val dialogFragment = MyDialogFragment.newInstance()
fragmentManager?.let { dialogFragment.show(it, MyDialogFragment.TAG) }

经过一些编辑(我在布局中有ViewPager2)，对话框片段变得太窄:

我使用了N1hk的解决方案:

override fun onActivityCreated(savedInstanceState: Bundle?) {
    super.onActivityCreated(savedInstanceState)

    dialog?.window?.attributes?.width = ViewGroup.LayoutParams.MATCH_PARENT
    dialog?.window?.attributes?.height = ViewGroup.LayoutParams.MATCH_PARENT
}

现在它已经定义了宽度和高度，而不是完整的活动大小。

我想说onCreateView和onCreateDialog。如果你有一个基于布局的对话片段，你可以使用这两种方法中的任何一种。

If you use onCreateView, then you should use onActivityCreated to set width. If you use onCreateDialog instead of onCreateView, you can set parameters there. onActivityCreated won't be needed. override fun onCreateDialog(savedInstanceState: Bundle?): Dialog { super.onCreateDialog(savedInstanceState) val view = activity?.layoutInflater?.inflate(R.layout.your_layout, null) val dialogBuilder = MaterialAlertDialogBuilder(context!!).apply { // Or AlertDialog.Builder(context!!).apply setView(view) // setCancelable(false) } view.text_view.text = "Some text" val dialog = dialogBuilder.create() // You can access dialog.window here, if needed. return dialog }

在我的情况下，这是由align_parentBottom="true"给RelativeLayout内的视图引起的。移除所有alignParentBottom的，并将所有布局改为垂直线性布局，问题消失了。

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));

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();
    

}

使用RelativeLayout作为DialogFragment的父元素