如何从表中读取数据并在组合框和文本框中显示 [英] How to read data from tables and display in a combobox and textbox

问题描述

我有一张表格，我希望从两列代码和主题的表中检索数据。这个表格有一个COMBOBOX和TEXTBOX.WHEN我从COMBOBOX中选择代码，然后在TEXTBOX上显示正确的主题



我尝试了什么：

DIM CON AS OLEDBCOMMAND =新OLEDBCOMMAND（PROVIDER = MICROSOFT.JET.OLEDB.4.0; DATA SOURCE = D;

CON.OPEN

DIM CMD AS OLEDBCOMMAND =新的OLEDBCOMMAND（从主题中选择，CON）

DR = CMD.EXECUTE READER（）

WHILE DR.READ = TRUE

CMBSUBJECT.ITEMS.ADD（DR（0））



TXTSUBJECT.TEXT = DR.GETVALUE（1）

END WHILE

解决方案

试试下面的例子

 Dim dt As New DataTable 
 dt.Columns.Add（Id，GetType（Int32））
 dt.Columns.Add（Data，GetType（String））
 dt.Rows.Add（1，Test1） ）
 dt.Rows.Add（2，Test2）
 ComboBox1.DataSource = dt 
 ComboBox1.Displ ayMember =数据
 ComboBox1.ValueMember =Id

 Private Sub ComboBox1_SelectedValueChanged（sender As Object，e As EventArgs）Handles ComboBox1.SelectedValueChanged 
 If Not IsNothing（ComboBox1.SelectedItem）Then 
 If Not IsNothing（ComboBox1.SelectedValue）Then 
 txtValueTxt .Text = ComboBox1.SelectedValue 
结束如果
 
 txtDisplayText.Text = DirectCast（ComboBox1.SelectedItem，System.Data.DataRowView）.Row.ItemArray（1）
 
结束如果
 
结束子
 

如果你有的话别忘了接受答案溶液

I HAVE A FORM WHERE I WANT TO RETRIEVE DATA FROM A TABLE WHERE TWO COLUMNS OF CODE AND SUBJECTS. THE FORM HAS A COMBOBOX AND TEXTBOX.WHEN I SELECT THE CODE FROM THE COMBOBOX THEN THE CORRECT SUBJECT IS DISPLAYED ON THE TEXTBOX

What I have tried:

DIM CON AS OLEDBCOMMAND=NEW OLEDBCOMMAND("PROVIDER=MICROSOFT.JET.OLEDB.4.0;DATA SOURCE=D;
CON.OPEN
DIM CMD AS OLEDBCOMMAND=NEW OLEDBCOMMAND("SELECT FROM SUBJECTS", CON)
DR=CMD.EXECUTE READER()
WHILE DR.READ=TRUE
CMBSUBJECT.ITEMS.ADD(DR(0))

TXTSUBJECT.TEXT=DR.GETVALUE(1)
END WHILE

解决方案

Just try with below example

Dim dt As New DataTable
        dt.Columns.Add("Id", GetType(Int32))
        dt.Columns.Add("Data", GetType(String))
        dt.Rows.Add(1, "Test1")
        dt.Rows.Add(2, "Test2")
        ComboBox1.DataSource = dt
        ComboBox1.DisplayMember = "Data"
        ComboBox1.ValueMember = "Id"

Private Sub ComboBox1_SelectedValueChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedValueChanged
       If Not IsNothing(ComboBox1.SelectedItem) Then
           If Not IsNothing(ComboBox1.SelectedValue) Then
               txtValueTxt.Text = ComboBox1.SelectedValue
           End If

           txtDisplayText.Text = DirectCast(ComboBox1.SelectedItem, System.Data.DataRowView).Row.ItemArray(1)

       End If

   End Sub

don't forget to accept answer if you got solution.

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