Datagridview不工作！ [英] Datagridview doesnt work!

问题描述

可能重复：

Datagridview does not work！

我已经编写代码来显示datagridview中的记录但它什么都不显示。我试图调试&当它进入GetData函数以下代码

I have written code to show records in a datagridview but it shows nothing. I have tried to debug & when it step into GetData function following codes

        Catch ex As Exception
        returnData = Nothing
        If connection.State = ConnectionState.Open Then
            connection.Close()
        End If

变成灰色它显示错误符号。当我把鼠标指针放在它上面时会显示消息。它说无法打开登录请求的数据库SUIMT，登录失败，用户MY-PC\James登录失败。请检查我的代码帮我摆脱这个问题&不要忘了用你的答案添加示例。

become gray & it shows error sign. When I take my mouse pointer on it it shows message. It says "Cannot open database SUIMT requested by the login. The login failed. Login failed for user 'MY-PC\James'". Please check my code & help me to get rid of this problem & dont forget to add example with your answer.

Imports System.Data.SqlClient

Public Class Form34
Private Const ConnectionString As String = "Server=.\SQLEXPRESS;" & _
"Database=SUIMT;Trusted_Connection=True"

Public Function GetData() As DataTable
    Dim SelectQry = "Select row_num, stu_id, tot_amou, paid, du, aoins, due, dt From monthly_instal where stu_id = '" & cmbdmiidn.Text & "' AND dt = '" & cmbdmidt.Text & "'"
    Dim connection As New SqlConnection(ConnectionString)
    Dim returnData As New DataTable("monthly_instal")
    Try
        connection.Open()
        Dim command As New SqlCommand(SelectQry, connection)
        Dim adapter = New SqlDataAdapter(command)
        adapter.Fill(returnData)
        con.Close()
    Catch ex As Exception
        returnData = Nothing
        If connection.State = ConnectionState.Open Then
            connection.Close()
        End If
    End Try
    Return returnData
End Function

Private Sub Form34_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    cmbdmidt.Items.Clear()
    cmbdmidt.Text = "DATE"
    cmbdmiidn.Items.Clear()
    cmbdmiidn.Text = "ID NUMBER"
    txtdmirn.Text = "ROW NUMBER"
    con = New ADODB.Connection
    con.Open("Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=SUIMT")
    rst = New ADODB.Recordset
    With rst
        .Open("Select * From monthly_instal", con, ADODB.CursorTypeEnum.adOpenStatic, ADODB.LockTypeEnum.adLockReadOnly)
        If .BOF = False Then
            .MoveFirst()
            While .EOF = False
                If Not cmbdmidt.Items.Contains(.Fields("dt").Value) Then
                    cmbdmidt.Items.Add(.Fields("dt").Value)
                End If
                .MoveNext()
            End While
        End If
        .Close()
    End With
    rst = New ADODB.Recordset
    With rst
        .Open("Select * From monthly_instal", con, ADODB.CursorTypeEnum.adOpenStatic, ADODB.LockTypeEnum.adLockReadOnly)
        If .BOF = False Then
            .MoveFirst()
            While .EOF = False
                If Not cmbdmiidn.Items.Contains(.Fields("stu_id").Value) Then
                    cmbdmiidn.Items.Add(.Fields("stu_id").Value)
                End If
                .MoveNext()
            End While
        End If
        .Close()
    End With
    Me.CREATEUSERToolStripMenuItem.Enabled = False
    Me.DELETEUSERToolStripMenuItem.Enabled = False
    Me.CHANGEPASSWORDToolStripMenuItem.Enabled = False
    Me.ASSIGNPERMISSIONToolStripMenuItem.Enabled = False
    Me.SHOWALLToolStripMenuItem.Enabled = False
    Me.CREATEACADEMICYEARToolStripMenuItem.Enabled = False
    Me.DELETEACADEMICYEARToolStripMenuItem.Enabled = False
    Me.CREATESESSIONToolStripMenuItem.Enabled = False
    Me.DELETESESSIONToolStripMenuItem.Enabled = False
    Me.CREATEDEPARTMENTToolStripMenuItem.Enabled = False
    Me.DELETEDEPARTMENTToolStripMenuItem.Enabled = False
    Me.CREATEEXAMTYPEToolStripMenuItem.Enabled = False
    Me.DELETEEXAMTYPEToolStripMenuItem.Enabled = False
    Me.CREATESUBJECTToolStripMenuItem.Enabled = False
    Me.DELETESUBJECTToolStripMenuItem.Enabled = False
    Me.ADMISSIONToolStripMenuItem.Enabled = False
    Me.DELETEADMISSIONToolStripMenuItem.Enabled = False
    Me.ADMISSIONREPORTToolStripMenuItem.Enabled = False
    Me.STUDENTINFORMATIONToolStripMenuItem.Enabled = False
    Me.DELETESTUDENTINFORMATIONToolStripMenuItem.Enabled = False
    Me.SEARCHSTUDENTINFORMATIONToolStripMenuItem.Enabled = False
    Me.STUDENTINFORMATIONREPORTToolStripMenuItem.Enabled = False
    Me.CREATESTUDENTRESULTToolStripMenuItem.Enabled = False
    Me.DELETESTUDENTRESULTToolStripMenuItem.Enabled = False
    Me.STUDENTRESULTREPORTToolStripMenuItem.Enabled = False
    Me.RESULTSHEETREPORTToolStripMenuItem.Enabled = False
    Me.CREATEMONTHLYINSTALLMENTToolStripMenuItem.Enabled = False
    Me.DELETEMONTHLYINSTALLMENTToolStripMenuItem.Enabled = False
    Me.MONTHLYINSTALLMENTREPORTToolStripMenuItem.Enabled = False
    Me.CREATEBALANCESHEETToolStripMenuItem.Enabled = False
    Me.DELETEBALANCESHEETToolStripMenuItem.Enabled = False
    Me.BALANCESHEETREPORTToolStripMenuItem.Enabled = False
    Me.ABOUTTHISPROGRAMToolStripMenuItem.Enabled = False
    Me.EXIToolStripMenuItem.Enabled = False
End Sub

Private Sub cmbdmidt_Leave(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmbdmidt.Leave
    dg1.DataSource = Nothing
    dg1.DataSource = GetData()


End Sub

Private Sub butdmiclo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butdmiclo.Click
    speak34.Speak("Delete monthly installment window has been closed successfully")
    Me.Close()
End Sub
End Class

推荐答案

看起来像我正在尝试使用网络凭据连接到数据库，但您在连接字符串中缺少一部分。

Looks to me like you are trying to use network credentials to connect to the database, but you are missing a part in the connection string.

尝试更改：

Private Const ConnectionString As String = "Server=.\SQLEXPRESS;" & _
"Database=SUIMT;Trusted_Connection=True"

为此：

Private Const ConnectionString As String = "Server=.\SQLEXPRESS;" & _
"Database=SUIMT;Trusted_Connection=True;Integrated Security=SSPI;"

这篇关于Datagridview不工作！的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！