How to use the upload and screenshot controls？

Question

I have an asp.net core mvc project, and I need a function request, the function of uploading pictures and allowing users to take screenshots at will, I goole a lot, I currently find a screenshot of a form, is there any upload function in the view?

private void button3_Click(object sender, EventArgs e)
        {
            Bitmap myImage = new Bitmap(this.Width, this.Height);
            Graphics g = Graphics.FromImage(myImage);
            g.CopyFromScreen(new Point(this.Location.X, this.Location.Y), new Point(0, 0), new Size(this.Width, this.Height));
            IntPtr t1= g.GetHdc();
            g.ReleaseHdc(t1);
            myImage.Save(@"c:\screen1.jpg");
}