通过Adobe PDF Reader控件叠加透明图像

Question

I'm trying to overlay a transparent image over the Adobe Reader Control. So I can read the PDF while the image is overlapped.

Currently I have the reader control and an imagebox, I got an overlay button that when I click it is supposed to make the image transparent so I can read the text "through" it, well at least where it's transparent in the image.

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }


    private void openToolStripMenuItem_Click(object sender, EventArgs e)
    {
        OpenFileDialog open = new OpenFileDialog();
        open.Title = "Open";
        open.Filter = "PDF|*.pdf";

        try
        {
            if (open.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                axAcroPDF1.LoadFile(open.FileName);
            }
        }
        catch (ArgumentException ex)
        {
            MessageBox.Show(ex.Message.ToString(), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message.ToString(), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }

    private void exitToolStripMenuItem_Click(object sender, EventArgs e)
    {
        Application.Exit();
    }

    private void overlayToolStripMenuItem_Click(object sender, EventArgs e)
    {
        pictureBox1.BackColor = Color.Transparent;

        pictureBox1.Parent = axAcroPDF1;



    }
}

My designer so far:

Answer 1

I can see your issue here, You are trying to set the colour of the picture box object to Transparent, this will not affect the image in any way.

Imagine you had no image loaded into your picture box, changing the back colour here will make a difference.

To achieve your desired effect, you will need to photo edit your picture and make a version which has transparency (Lowering Alpha and saving as .PNG). Then once you click your button you need to swap the original image to the newly created transparent image. You can use the line pictureBox1.Image = Image.FromFile("Path") in this case.