如何使用 C# 设置 comboBox 中的所选项目以匹配我的字符串？

Question

I have a string "test1" and my comboBox contains test1 , test2 , and test3 . How do I set the selected item to "test1"? That is, how do I match my string to one of the comboBox items?

I was thinking of the line below, but this doesn't work.

comboBox1.SelectedText = "test1"; 

Answer 1

这应该可以解决问题：

Combox1.SelectedIndex = Combox1.FindStringExact("test1")

Answer 2

Have you tried the Text property? It works for me.

ComboBox1.Text = "test1";

The SelectedText property is for the selected portion of the editable text in the textbox part of the combo box.

Answer 3

Assuming that your combobox isn't databound you would need to find the object's index in the "items" collection on your form and then set the "selectedindex" property to the appropriate index.

comboBox1.SelectedIndex = comboBox1.Items.IndexOf("test1");

Keep in mind that the IndexOf function may throw an argumentexception if the item isn't found.

Answer 4

如果您的 ComboBox 中的项目是字符串，您可以尝试：

comboBox1.SelectedItem = "test1";

Answer 5

For me this worked only:

foreach (ComboBoxItem cbi in someComboBox.Items)
{
    if (cbi.Content as String == "sometextIntheComboBox")
    {
        someComboBox.SelectedItem = cbi;
        break;
    }
}

MOD: and if You have your own objects as items set up in the combobox, then substitute the ComboBoxItem with one of them like:

foreach (Debitor d in debitorCombo.Items)
{
    if (d.Name == "Chuck Norris")
    {
        debitorCombo.SelectedItem = d;
        break;
    }
}

Answer 6

ComboBox1.SelectedIndex= ComboBox1.FindString("Matching String");

在 Windows 窗体中试试这个。

Answer 7

SelectedText is to get or set the actual text in the string editor for the selected item in the combobox as documented here . This goes uneditable if you set:

comboBox1.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;

Use:

comboBox1.SelectedItem = "test1";

or:

comboBox1.SelectedIndex = comboBox1.Items.IndexOf("test1");

Answer 8

I've used an extension method:

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;
        }
    } 
}

Then just consume the method:

ddl.SelectItemByValue(value);

Answer 9

comboBox1.SelectedItem.Text = "test1";

Answer 10

假设 test1、test2、test3 属于 comboBox1 集合，下面的语句将起作用。

comboBox1.SelectedIndex = 0; 

Answer 11

I've filled my ComboBox with een DataTable filled from a database. Then I've set the DisplayMember and the ValueMember. And I use this code to set the selected item.

foreach (DataRowView Row in ComboBox1.Items)
{
    if (Row["ColumnName"].ToString() == "Value") ComboBox1.SelectedItem = Row;
}

Answer 12

This solution is based on MSDN with some modifications I made.

• 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; }

I hope I helped!

Answer 13

我使用KeyValuePair进行 ComboBox 数据绑定，我想按值查找项目，因此这在我的情况下有效：

comboBox.SelectedItem = comboBox.Items.Cast<KeyValuePair<string,string>>().First(item=> item.Value == "value to match");

Answer 14

• Enumerate ListItems in combobox
• Get equal ones listindex set combobox
• Set listindex to the found one.

But if I see such a code as a code reviewer, I would recommend to reconsider all the method algorithm.

Answer 15

You don't have that property in the ComboBox. You have SelectedItem or SelectedIndex. If you have the objects you used to fill the combo box then you can use SelectedItem.

If not you can get the collection of items (property Items) and iterate that until you get the value you want and use that with the other properties.

hope it helps.

Answer 16

_cmbTemplates.SelectedText = "test1"

或者可能

_cmbTemplates.SelectedItem= _cmbTemplates.Items.Equals("test1");

Answer 17

Find mySecondObject (of type MyObject) in combobox (containing a list of MyObjects) and select the item:

foreach (MyObject item in comboBox.Items)
{
   if (item.NameOrID == mySecondObject.NameOrID)
    {
        comboBox.SelectedItem = item;
        break;
    }
}

Answer 18

设置 ComboBox 项的所有方法、技巧和代码行将无法工作，直到 ComboBox 具有父项。

Answer 19

I have created a Function which will return the Index of the Value

        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;
        }

Answer 20

这对我有用.....

comboBox.DataSource.To<DataTable>().Select(" valueMember = '" + valueToBeSelected + "'")[0]["DislplayMember"];

Answer 21

I know this isn't what the OP asked but could it be that they don't know? There are already several answers here so even though this is lengthy I thought it could be useful to the community.

Using an enum to fill a combo box allows for easy use of the SelectedItem method to programmatically select items in the combobox as well as loading and reading from the combobox.

public enum Tests
    {
        Test1,
        Test2,
        Test3,
        None
    }

// Fill up combobox with all the items in the Tests enum
    foreach (var test in Enum.GetNames(typeof(Tests)))
    {
        cmbTests.Items.Add(test);
    }

    // Select combobox item programmatically
    cmbTests.SelectedItem = Tests.None.ToString();

If you double click the combo box you can handle the selected index changed event:

private void cmbTests_SelectedIndexChanged(object sender, EventArgs e)
{
    if (!Enum.TryParse(cmbTests.Text, out Tests theTest))
    {
        MessageBox.Show($"Unable to convert {cmbTests.Text} to a valid member of the Tests enum");
        return;
    }

    switch (theTest)
    {
        case Tests.Test1:
            MessageBox.Show("Running Test 1");
            break;

        case Tests.Test2:
            MessageBox.Show("Running Test 2");
            break;

        case Tests.Test3:
            MessageBox.Show("Running Test 3");
            break;

        case Tests.None:

            // Do nothing

            break;

        default:
            MessageBox.Show($"No support for test {theTest}.  Please add");
            return;
    }
}

You can then run tests from a button click handler event:

 private void btnRunTest1_Click(object sender, EventArgs e)
    {
        cmbTests.SelectedItem = Tests.Test1.ToString();
    }

Answer 22

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

For your case you can use

DropDownList.Items.FindByText("Text");

Answer 23

if you are binding Datasource via Dataset, then you should use "SelectedValue"

cmbCategoryList.SelectedValue = (int)dsLookUp.Tables[0].Select("WHERE PRODUCTCATEGORYID = 1")[0]["ID"];

Answer 24

combo.Items.FindByValue("1").Selected = true;

Answer 25

你可以说comboBox1.Text = comboBox1.Items[0].ToString();

Answer 26

请尝试这种方式，它对我有用：

Combobox1.items[Combobox1.selectedIndex] = "replaced text";

Answer 27

It should work

Yourcomboboxname.setselecteditem("yourstring");

And if you want to set database string use this

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