VB.NET中DataGridView删除指定数据行，并更新数据库

来源：互联网发布：桌游淘宝编辑：程序博客网时间：2024/05/12 11:08

收费系统需要这样一个功能：首先用DataGridView浏览所有用户信息，然后可以删除指定行的用户信息，最后更新这一变化。界面如图：

1、首先检测要删除的用户是否是当前正在使用的用户：

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'查看改用户是否正在被使用,若正在使用则不能删除
If Trim(DGVuser.CurrentRow.Cells(0).Value) = frmLogin.txtUID.Text Then
MsgBox("该用户正在使用，不能删除！", MsgBoxStyle.OkOnly, "正在使用")
Exit Sub
End If

<span style="FONT-FAMILY: KaiTi_GB2312; FONT-SIZE: 18px">'查看改用户是否正在被使用,若正在使用则不能删除If Trim(DGVuser.CurrentRow.Cells(0).Value) = frmLogin.txtUID.Text ThenMsgBox("该用户正在使用，不能删除！", MsgBoxStyle.OkOnly, "正在使用")Exit SubEnd If</span>

2、然后在删除指定数据行：

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'删除datagridview中的数据行
'DGVuser.Rows.Remove(DGVuser.CurrentRow) 也可
DGVuser.Rows.RemoveAt(DGVuser.CurrentRow.Index)

<span style="FONT-FAMILY: KaiTi_GB2312; FONT-SIZE: 18px">          '删除datagridview中的数据行  'DGVuser.Rows.Remove(DGVuser.CurrentRow) 也可DGVuser.Rows.RemoveAt(DGVuser.CurrentRow.Index)</span>

3、建立一个模板类，用于传递数据：

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Public Class dm_datatable
Private _dt As DataTable
Public Property DT As DataTable
Get
Return _dt
End Get
Set(ByVal value As DataTable)
_dt = value
End Set
End Property
End Class

<span style="FONT-FAMILY: KaiTi_GB2312; FONT-SIZE: 18px">Public Class dm_datatablePrivate _dt As DataTablePublic Property DT As DataTableGetReturn _dtEnd GetSet(ByVal value As DataTable)_dt = valueEnd SetEnd PropertyEnd Class</span>

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<span style="WHITE-SPACE: normal"><span style="FONT-FAMILY: KaiTi_GB2312; FONT-SIZE: 18px"> </span></span>

4、用表示层，用模板类传递数据：

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Dim dt As New DataModel.dm_datatable
dt.DT = DGVuser.DataSource

<span style="FONT-FAMILY: KaiTi_GB2312; FONT-SIZE: 18px">Dim dt As New DataModel.dm_datatabledt.DT = DGVuser.DataSource</span>

[vb] view plaincopyprint?

<span style="WHITE-SPACE: normal"><span style="FONT-FAMILY: KaiTi_GB2312; FONT-SIZE: 18px"> </span></span>

5、在数据访问层，编写修改数据库的函数：

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'删除指定用户
Public Function deleteUser(ByVal dm_dt As DataModel.dm_datatable) As Boolean
Dim connString As String = _
"Persist Security Info=true;Data Source=192.168.24.158;Initial Catalog=CR_Charge_SYS;User ID=sa;PWD=123456"
Dim sqlconn As New SqlConnection(connString)
Dim sqltxt As String = "select * from User_info"
Dim sqlcmd As New SqlCommand(sqltxt, sqlconn)
Dim da As New SqlDataAdapter(sqlcmd)
Dim ds As New DataSet
Dim dt As New DataTable
da.UpdateCommand = sqlcmd
Dim mybuilder As New SqlCommandBuilder(da)
Try
dt = dm_dt.DT.Copy
ds.Tables.Add(dt)
sqlconn.Open()
da.Update(ds, "User_info")
Return True
Catch ex As Exception
MsgBox(ex.Message)
Return False
Finally
sqlconn.Close()
sqlcmd = Nothing
End Try
Return Nothing
End Function

<span style="FONT-FAMILY: KaiTi_GB2312; FONT-SIZE: 18px">'删除指定用户Public Function deleteUser(ByVal dm_dt As DataModel.dm_datatable) As BooleanDim connString As String = _"Persist Security Info=true;Data Source=192.168.24.158;Initial Catalog=CR_Charge_SYS;User ID=sa;PWD=123456"Dim sqlconn As New SqlConnection(connString)Dim sqltxt As String = "select * from User_info"Dim sqlcmd As New SqlCommand(sqltxt, sqlconn)Dim da As New SqlDataAdapter(sqlcmd)Dim ds As New DataSetDim dt As New DataTableda.UpdateCommand = sqlcmdDim mybuilder As New SqlCommandBuilder(da)Trydt = dm_dt.DT.Copyds.Tables.Add(dt)sqlconn.Open()da.Update(ds, "User_info")Return TrueCatch ex As ExceptionMsgBox(ex.Message)Return FalseFinallysqlconn.Close()sqlcmd = NothingEnd TryReturn NothingEnd Function</span>

6、在业务逻辑层，编写传递数据访问层的函数：

[vb] view plaincopyprint?

'删除指定用户
Public Function deleteUser(ByVal dt As DataModel.dm_datatable) As Boolean
Dim sqlUserInfo As New ChargeSystemDAL.dal_User_info
Return sqlUserInfo.deleteUser(dt)
End Function

<span style="FONT-FAMILY: KaiTi_GB2312; FONT-SIZE: 18px">'删除指定用户Public Function deleteUser(ByVal dt As DataModel.dm_datatable) As BooleanDim sqlUserInfo As New ChargeSystemDAL.dal_User_infoReturn sqlUserInfo.deleteUser(dt)End Function</span>

7、最后，在表示层，调用业务逻辑层的函数：

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Dim dt As New DataModel.dm_datatable
'数据更改更新到数据库
If bllUserinfo.deleteUser(dt) = True Then
MsgBox("成功删除用户！", MsgBoxStyle.OkOnly, "成功")
Exit Sub
Else
MsgBox("未能成功删除用户，详情请咨询管理员！", MsgBoxStyle.OkOnly, "失败")
Exit Sub
End If

<span style="FONT-FAMILY: KaiTi_GB2312; FONT-SIZE: 18px">Dim dt As New DataModel.dm_datatable'数据更改更新到数据库If bllUserinfo.deleteUser(dt) = True ThenMsgBox("成功删除用户！", MsgBoxStyle.OkOnly, "成功")Exit SubElseMsgBox("未能成功删除用户，详情请咨询管理员！", MsgBoxStyle.OkOnly, "失败")Exit SubEnd If</span>

在5中，如果直接这样调用：ds.Tables.Add(dm_dt.DT)，则会产生错误：DT已存在DataSet。所以dm_dt.DT复制后才能为ds所使用。

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