想检查一个GridView是否包含重复值

Question

我想检查按钮单击事件中gridview是否包含重复值

Answer 1

这将在dataGridView中找到重复的值，并将它们添加到alreadySeen列表中。然后显示消息框。

    private void button2_Click_1(object sender, EventArgs e)
    {
        int i = 0,j=0;
        string check1 = "",check2="";
        List<string> alreadySeen = new List<string>();

        for (i=0;i<dataGridView1.Rows.Count-1;i++)
        {
          check1 = this.dataGridView1.Rows[i].Cells[0].Value.ToString();
            j = i;
            for (j=j+1; j < dataGridView1.Rows.Count - 1; j++)
            {
              check2 = this.dataGridView1.Rows[j].Cells[0].Value.ToString();
                if (check1==check2)
                {
                    if (!alreadySeen.Contains(check1))
                        alreadySeen.Add(check1);
                }
            }   
         }

        //Show duplicate value
        foreach (var x in alreadySeen)
        {
            MessageBox.Show(x);
        }
    }