20210603
大屏設備使用DialogFragment時出現(xiàn)了對話框大小差別很大的情況，需要做一些固定大小的限制毡惜，
DialogFragment的源碼中渊胸，有個mDialog對象橱健，就是對話框而钞，整個DialogFragment.java代碼中只有onStart()方法調用了mDialog.show()的方法，因此如果需要對它的大小進行修改拘荡，那么應該是重寫DialogFragment的onStart(),
假如想固定Dialog的長寬都是整個屏幕大小的60%,那么就可以進行以下操作：

1.獲取整個屏幕的大小

public class PickerDialogFragment extends DialogFragment {
    private Point getScreenSize() {
        final Point size = new Point();
        final FragmentActivity activity = requireActivity();
        final WindowManager windowManager = activity.getWindowManager();
        final Display display = windowManager.getDefaultDisplay();
        display.getSize(size);
        return size;
    }
}

其中point.x 就是屏幕的寬度臼节，point.y 就是屏幕的高度

2.設置dialog的大小
設置dialog大小只能在它顯示show后，設置dialog所在的window的屬性，才能生效
（之后調用show之后网缝，才有對應的Window對象）

final Dialog dialog = getDialog();
if (dialog == null) {
    return;
}
final Window window = dialog.getWindow();
if (window == null) {
    return;
}
final Point size = getScreenSize();
final WindowManager.LayoutParams attributes = window.getAttributes();
attributes.height = (int) (size.y * 0.6);
attributes.width = (int) (size.x * 0.6);
window.setAttributes(attributes);

全部代碼就是：

package com.hello.world;

import android.app.Dialog;
import android.graphics.Point;
import android.view.Display;
import android.view.Window;
import android.view.WindowManager;

import androidx.fragment.app.DialogFragment;
import androidx.fragment.app.FragmentActivity;

public class PickerDialogFragment extends DialogFragment {

    @Override
    public void onStart() {
        super.onStart();
        final Dialog dialog = getDialog();
        if (dialog == null) {
            return;
        }
        final Window window = dialog.getWindow();
        if (window == null) {
            return;
        }
        final Point size = getScreenSize();
        final WindowManager.LayoutParams attributes = window.getAttributes();
        attributes.height = (int) (size.y * 0.6);
        attributes.width = (int) (size.x * 0.6);
        window.setAttributes(attributes);
    }

    private Point getScreenSize() {
        final Point size = new Point();
        final FragmentActivity activity = requireActivity();
        final WindowManager windowManager = activity.getWindowManager();
        final Display display = windowManager.getDefaultDisplay();
        display.getSize(size);
        return size;
    }

}