问如何读取另一个按钮中已打开的文件，直接单击事件。(即，在单击按钮时没有打开文件对话框)

EN

// class scoped variables
       [ThePolyFileType] (pick the right one here :) geometry = null;

        void OpenWithDialog()
        {
            var ofd = new OpenFileDialog();

            ofd.Filter = "Triangle polygon file|*.poly";

            if (ofd.ShowDialog() == DialogResult.OK)
            {
                OpenPolyFile(ofd.FileName);
            }
        }

        void OpenPolyFile(string file)
        {
            geometry = TriangleNet.IO.FileReader.ReadPolyFile(file);
            // ...
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (geometry != null)
            {
              //do your stuff
            }
        }

private string filename;

void OpenWithDialog()
{
    var ofd = new OpenFileDialog();

    ofd.Filter = "Triangle polygon file|*.poly";

    if (ofd.ShowDialog() == DialogResult.OK)
    {
        OpenPolyFile(ofd.FileName);
        filename = ofd.FileName
    }
}

private void button1_Click(object sender, EventArgs e)
{
    // now you can read the file.
    //File.ReadAllText(filename); //OR

     TriangleNet.IO.FileReader.ReadPolyFile(file); 
}