这个方案是基于MSDN的，我做了一些修改。

It finds exact or PART of string and sets it. private int lastMatch = 0; private void textBoxSearch_TextChanged(object sender, EventArgs e) { // Set our intial index variable to -1. int x = 0; string match = textBoxSearch.Text; // If the search string is empty set to begining of textBox if (textBoxSearch.Text.Length != 0) { bool found = true; while (found) { if (comboBoxSelect.Items.Count == x) { comboBoxSelect.SelectedIndex = lastMatch; found = false; } else { comboBoxSelect.SelectedIndex = x; match = comboBoxSelect.SelectedValue.ToString(); if (match.Contains(textBoxSearch.Text)) { lastMatch = x; found = false; } x++; } } } else comboBoxSelect.SelectedIndex = 0; }

希望我能帮上忙!

  ListItem li = DropDownList.Items.FindByValue("13001");
  DropDownList.SelectedIndex = ddlCostCenter.Items.IndexOf(li);

你的案子可以用

DropDownList.Items.FindByText("Text");

如果组合框中的项目是字符串，您可以尝试:

comboBox1.SelectedItem = "test1";

我使用了一个扩展方法:

public static void SelectItemByValue(this ComboBox cbo, string value)
{
    for(int i=0; i < cbo.Items.Count; i++)
    {
        var prop = cbo.Items[i].GetType().GetProperty(cbo.ValueMember);
        if (prop!=null && prop.GetValue(cbo.Items[i], null).ToString() == value)
        {
             cbo.SelectedIndex = i;
             break;
        }
    } 
}

然后使用该方法:

ddl.SelectItemByValue(value);

应该可以

Yourcomboboxname.setselecteditem("yourstring");

如果你想设置数据库字符串，使用这个

Comboboxname.setselecteditem(ps.get string("databasestring"));

我已经创建了一个函数，它将返回值的索引

        public static int SelectByValue(ComboBox comboBox, string value)
        {
            int i = 0;
            for (i = 0; i <= comboBox.Items.Count - 1; i++)
            {
                DataRowView cb;
                cb = (DataRowView)comboBox.Items[i];
                if (cb.Row.ItemArray[0].ToString() == value)// Change the 0 index if your want to Select by Text as 1 Index
                {
                    return i;
                }
            }
            return -1;
        }