Close code generated win form with eventhandler

Question

How to close a code generated form when a listbox item is double clicked.

Here is my code

    private void btn_batchList_Click(object sender, EventArgs e)
    {
        string[] batchList = BACH_Outward.GetOutBatchList(txtBranchId.Text, dtpHouseDt.Value.ToString("dd/MM/yyyy"), cmbCLRTYPE.SelectedValue.ToString(), "T");
        if (batchList == null)
        {
            return;
        }
        Form form = new Form();
        form.FormBorderStyle = FormBorderStyle.FixedDialog;
        form.MaximizeBox = false;
        form.MinimizeBox = false;
        form.Size = new Size(150, 325);
        form.StartPosition = FormStartPosition.Manual;
        form.Location = new Point(this.Right - 200, this.Top + 100);
        form.Opacity = 50;
        form.Text = "Batch List";
        form.Move += new System.EventHandler(this.OnMove);

        ListBox BatchList = new ListBox();
        BatchList.Size = new System.Drawing.Size(140, 315);
        form.Controls.Add(BatchList);            
        BatchList.DataSource = batchList;
        BatchList.MouseDoubleClick += new System.Windows.Forms.MouseEventHandler(this.listBox_MouseDoubleClick);
        form.ShowDialog();
    }

private void listBox_MouseDoubleClick(object sender, MouseEventArgs e)
    {
        ListBox listBox = (ListBox)sender;
        if (listBox.SelectedIndex != -1)
        {
            var rect = listBox.GetItemRectangle(listBox.SelectedIndex);
            if (rect.Contains(e.Location))
            {
                // process item data here
                TxtBatchNo.Text = listBox.SelectedValue.ToString();
//want to close the popup form here.
            }

        }
    }

Now I want to close the popup form when user double clicks on an Item of the listBox.

Answer 1

you have to declare form object in a scope where both method can access it. then invoke the method form.Close() or change the visibility to hidden if you need to show it later.

Answer 2

You can close the window by obtaining a reference to the Form object and calling Close() on it:

((Form)listBox.TopLevelControl).Close();

However, I would strongly suggest creating a new form in your project so that it is its own class, and encapsulates all of its own logic. It appears that you are creating a Form object directly from within another form and mixing the logic of the two forms together. This is bad design and will make future maintenance more difficult.

Answer 3

This is where a closure can be nice. Simply close over the form.

 BatchList.MouseDoubleClick += (sender, args) => {
   if (someCondition) {
     form.Close();
   }
 }