我复制了layout.xml文件，并简单地将onclick操作添加到代码中：

<Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/first_semis"
        android:onClick="capture"
        />

我在你的链接中使用了代码，它确实非常有效：
这是我的mainactivity.java文件：

package com.example.androidlayout;

import androidx.appcompat.app.AppCompatActivity;

import android.content.res.Configuration;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.widget.LinearLayout;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    }
    public void capture(View view){
        Bitmap photo = getBitmapFromView((LinearLayout) findViewById(R.id.layout_capture));
        String savedImageURL = MediaStore.Images.Media.insertImage(
                getContentResolver(),
                photo,
                "your_layout",
                "image"
        );
    }
    public static Bitmap getBitmapFromView(View view) {
        //Define a bitmap with the same size as the view
        Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(),Bitmap.Config.ARGB_8888);
        //Bind a canvas to it
        Canvas canvas = new Canvas(returnedBitmap);
        //Get the view's background
        Drawable bgDrawable =view.getBackground();
        if (bgDrawable!=null)
            //has background drawable, then draw it on the canvas
            bgDrawable.draw(canvas);
        else
            //does not have background drawable, then draw white background on the canvas
            canvas.drawColor(Color.WHITE);
        // draw the view on the canvas
        view.draw(canvas);
        //return the bitmap
        return returnedBitmap;
    }
}

它会将图像保存到您的图库中。