从列表框中选择一项，一个接一个

Question

I am working on Microsoft Visual C# 2010 Express. Actually, when I execute my code, I get a listbox containing N items. There is a list of items with their size in my database. I am using Microsoft Access 2007 database. I want to display the total size of items present in listbox into a label below the listbox. I have my code for displaying the size. I just want to know how to select already present data in a listbox without any button click. I think loop will be used.

Answer 1

Do what you want to do but i don't understand why you need to select an item form listbox. but you can get the items by

listBox1.Items[i] and then can calculate the size.

Use below code to do that what you wanted.

  for (int i = 0; i < listBox1.Items.Count; i++)
        {
            listBox1.SelectedItem = listBox1.Items[i];
            //Calculate the total size of items present in listbox here 
        }

Answer 2

I just want to know how to select already present data in a listbox without any button click.

I think the MouseDoubleClick event is what you want to handle. To add the handler for that, in the designer, in the properties window, click on the little yellow lightning bolt icon. This will show a list of events. Double-Click on the one you want to handle and the system will create the stub for it and add the handler to the control. A loop in side here will allow you get what you need:

    private void listBox1_MouseDoubleClick(object sender, MouseEventArgs e)
    {
        foreach (string item in listBox1.Items)
        {
            //Pass item to your size routine here
        }
    }