How to use OpenFileDialog Control

Drag and drop OpenFileDialog control from toolbox on the window Form.

Drag and drop PictureBox and Button.

Code:

Write code in Button click event.

Double click on Click event to open Button click event handler.

private void btnOpenFile_Click(object sender, EventArgs e)
{
        // OpenFileDialog will open
        openFileDialog1.ShowDialog();
        // selected Image will show in the pictureBox
        pictureBox1.Image = Image.FromFile(openFileDialog1.FileName);
}

Run the project

When you click SelectImage button then OpenFileDialog will open.

Select Image which you want to show in the PictureBox. When you select Image and click open then selected Image will show in PictureBox on the Form.