.NET winforms bug (savefiledialog)?

Question

The following example simply shows and SaveFileDialog on a ToolStripButton click event. If I pre-make the SaveFileDialog and then double-click the ToolStripButton, the application stackoverflows. Seems like a bug in Winforms to me. Not optimistic on getting a fix or even a response from MS (even a couple years ago they just responded "no more bug fixes for winforms" when i reported a bug), so I'd just like some opinions on whether this is a bug or I'm doing something wrong.

using System;
using System.Windows.Forms;

namespace ToolStripDoubleClickSaveDialog
{
   public partial class Form1 : Form
   {
      SaveFileDialog sfd = new SaveFileDialog();

      public Form1()
      {
         InitializeComponent();
      }

      private void toolStripButton1_Click(object sender, EventArgs e)
      {
         sfd.ShowDialog(this);
      }

      private void InitializeComponent()
      {
         this.toolStrip1 = new System.Windows.Forms.ToolStrip();
         this.toolStripButton1 = new System.Windows.Forms.ToolStripButton();
         this.toolStrip1.SuspendLayout();
         this.SuspendLayout();
         // 
         // toolStrip1
         // 
         this.toolStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {
            this.toolStripButton1});
         this.toolStrip1.Location = new System.Drawing.Point(0, 0);
         this.toolStrip1.Name = "toolStrip1";
         this.toolStrip1.Size = new System.Drawing.Size(284, 25);
         this.toolStrip1.TabIndex = 0;
         this.toolStrip1.Text = "toolStrip1";
         // 
         // toolStripButton1
         // 
         this.toolStripButton1.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Text;
         this.toolStripButton1.ImageTransparentColor = System.Drawing.Color.Magenta;
         this.toolStripButton1.Name = "toolStripButton1";
         this.toolStripButton1.Size = new System.Drawing.Size(23, 22);
         this.toolStripButton1.Text = "double click me";
         this.toolStripButton1.Click += new System.EventHandler(this.toolStripButton1_Click);
         // 
         // Form1
         // 
         this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
         this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
         this.ClientSize = new System.Drawing.Size(284, 262);
         this.Controls.Add(this.toolStrip1);
         this.Name = "Form1";
         this.Text = "Form1";
         this.toolStrip1.ResumeLayout(false);
         this.toolStrip1.PerformLayout();
         this.ResumeLayout(false);
         this.PerformLayout();

      }

      private System.Windows.Forms.ToolStrip toolStrip1;
      private System.Windows.Forms.ToolStripButton toolStripButton1;
   }
}

Answer 1

Okay, so the issue comes about when the control is Doubleclicked because it's set to open the dialog on a single click and both click events are attempting to open the dialog at the same time. My guess is that while the dialog is loading, the app goes into a short idle state briefly before the dialog opens, long enough to allow for the other event to get called as well, causing an error when it calls ShowDialog() twice.

To prevent this, you can get the System.Runtime.Remoting.Lifetime.Lease of the window and double check it's not active before showing it.

using System.Runtime.Remoting.Lifetime;
//.....
private SaveFileDialog sfd;
private ILease sfdLease;

public Form1()
{
    InitializeComponent();
    sfd = new SaveFileDialog();
    sfdLease= (ILease)sfd.InitializeLifetimeService();
}
private void toolStripButton1_Click(object sender, EventArgs e)
{
    if(sfdLease.CurrentState != LeaseState.Active)
        sfd.ShowDialog(this);
}