vb.net 如何清除组合框文本
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How to clear ComboBox Text
提问by Sky Scraper
when i use ComboBox1.Items.Clear()it clears all the items in the combobox and when i use ComboBox1.SelectedIndex = -1it doesn't show any text and when i choose any of the entry, it doesn't show, it's blank.
当我使用ComboBox1.Items.Clear()它时会清除组合框中的所有项目，当我使用ComboBox1.SelectedIndex = -1它时不显示任何文本，当我选择任何条目时，它不显示，它是空白的。
this is my code to show my database fields into a ComboBox, and
这是将我的数据库字段显示到 ComboBox 中的代码，以及
Imports MySql.Data.MySqlClient
Public Class Form4
Dim con As New MySqlConnection
Dim cmd As New MySqlCommand
Dim da As New MySqlDataAdapter
Private Sub Form4_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
con.ConnectionString = ("server=localhost;user id=root;database=db")
Try
con.Open()
With cmd
.Connection = con
.CommandText = "SELECT CONCAT_WS(' ', cfname, cmname, clname,'from', cparty,'party') as names, " & _
"cpos, cid from candidate WHERE cpos='President'"
With ComboBox7
Dim dv6 = New DataView(dt, "cpos='President'", "", DataViewRowState.CurrentRows)
.DisplayMember = "names"
.ValueMember = "names"
.DataSource = dv6
End With
Catch ex As Exception
MsgBox(ex.Message)
End Try
con.Close()
End Sub
End Class
回答by ElektroStudios
How to clear ComboBox Text
如何清除组合框文本
You should use:
你应该使用：
ComboBox1.ResetText()
Or else:
要不然：
ComboBox1.Text = String.Empty
回答by Elton Costa
In Windows Forms and WPF, you can say:
在 Windows 窗体和 WPF 中，您可以说：
ComboBox1.Text = String.Empty
ComboBox1.Text = String.Empty
回答by Anthony
While setting the text to ""might work, it will only clear the text and if your combo box populates some text boxes then these will remain with the previous values. Try:
虽然将文本设置为""可能有效，但它只会清除文本，如果您的组合框填充了一些文本框，那么这些文本框将保留以前的值。尝试：
ComboBox1.SelectedItem = Nothing
This will also work if your combo box is grayed out such that you can't type anything into it.
如果您的组合框变灰以至于您无法在其中输入任何内容，这也将起作用。
