How to avoid entering duplicate item from one textbox to other

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Hi all,

I have two listboxs so when i select one item and click button then the items from listbox1 will move to listbox2.It is done but if there are similar items in listbox1 after moving one item it should not allow to move the duplicate items rather it will show a message item already available.How to do it.

My Code below

C#

private void btnright_Click(object sender, EventArgs e)
        {

            listBox2.Items.Add(listBox1.SelectedItem);
            int i = 0;
            i = listBox1.SelectedIndex;
            listBox1.Items.RemoveAt(i);

        }


        private void btnleft_Click(object sender, EventArgs e)
        {
            listBox1.Items.Add(listBox2.SelectedItem);
            int i = 0;
            i = listBox2.SelectedIndex;
            listBox2.Items.RemoveAt(i);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            listBox1.Items.Add("a");
            listBox1.Items.Add("a");
            listBox1.Items.Add("b");
            listBox1.Items.Add("c");
            listBox1.Items.Add("d");
            listBox1.Items.Add("e");
            listBox1.Items.Add("f");


        }

Thanks

Posted 3-Dec-11 0:52am

3796068

Updated 3-Dec-11 0:54am

v2

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2 solutions

Solution 1

Your question makes no real sense based on your sample. You say an object can't be added to the 2nd listbox if it's already IN the listbox, yet, more than one of that item IS allowed in the first listbox. This is nonsense. Because you're implying that the two instances of "a" are the same in one listbox, but DIFFERENT in the other.

Posted 3-Dec-11 1:00am

#realJSOP

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**Manoj K Bhoir** · Accepted Answer · 2011-12-03T01:41:00

You can use the following code on btnRight

C#

if (listBox2.Items.Contains(listBox1.SelectedItem)== true)
          {
              MessageBox.Show("Duplicate Value");
          }
          else
          {
              listBox2.Items.Add(listBox1.SelectedItem);
              i = 0;
              i = listBox1.SelectedIndex;
              listBox1.Items.RemoveAt(i);

          }

I hope it will help you. :)

-MKB