Vb.Net程序设计：代码片段集

'回车键，跳格，并选中内容。 

Private Sub FrmFiber_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles MyBase.KeyPress

        If e.KeyChar = ChrW(Keys.Enter) Then
            Me.SelectNextControl(Me.ActiveControl, True, False, True, True)
            If TypeOf Me.ActiveControl Is TextBox Then
                Dim ctlTextBox As TextBox = CType(Me.ActiveControl, TextBox)
                If String.IsNullOrEmpty(ctlTextBox.Text) = False Then
                    ctlTextBox.SelectAll()
                End If
            End If
        End If

    End Sub

'对两个Datatable的结构相同进行合并:

Dim db As Datatable = Nothing
Dim dt As DataTable = ds.Tables(0)
'''/两个datatable进行合并
db = dt.Copy()
Dim foundRows As DataRow() = dt.Select()
For i As Integer = 0 To foundRows.Length - 1
db.ImportRow(foundRows(i))
Next


'两个结构一样的DT合并 
Dim DataTable1 As New DataTable()
Dim DataTable2 As New DataTable()
Dim newDataTable As DataTable = DataTable1.Clone()

Dim obj As Object() = New Object(newDataTable.Columns.Count - 1) {}
For i As Integer = 0 To DataTable1.Rows.Count - 1
DataTable1.Rows(i).ItemArray.CopyTo(obj, 0)
newDataTable.Rows.Add(obj)
Next

For i As Integer = 0 To DataTable2.Rows.Count - 1
DataTable2.Rows(i).ItemArray.CopyTo(obj, 0)
newDataTable.Rows.Add(obj)
Next

  Private Sub BtnExeQuery_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnExeQuery.Click

        Dim cd As String
        Dim cmd As New SqlClient.SqlCommand
        Dim strWhere As String = String.Empty
        cd = " and "
        If String.IsNullOrEmpty(Me.TxtLotNo.Text.Trim) = False Then
            strWhere &= (IIf(String.IsNullOrEmpty(strWhere), "", cd) & "strLotNo like (@strLotNo)")
            cmd.Parameters.Add(New SqlClient.SqlParameter("@strLotNo", Me.TxtLotNo.Text.Trim & "%"))
        End If
        If String.IsNullOrEmpty(Me.TxtColorNo.Text.Trim) = False Then
            strWhere &= (IIf(String.IsNullOrEmpty(strWhere), "", cd) & "strItemName like (@strItemName)")
            cmd.Parameters.Add(New SqlClient.SqlParameter("@strItemName", Me.TxtColorNo.Text.Trim & "%"))
        End If

        If String.IsNullOrEmpty(Me.TxtPly.Text.Trim) = False Then
            strWhere &= (IIf(String.IsNullOrEmpty(strWhere), "", cd) & "lngPly = (@lngPly)")
            cmd.Parameters.Add(New SqlClient.SqlParameter("@lngPly", CInt(Me.TxtPly.Text.Trim)))
        End If


        If String.IsNullOrEmpty(Me.TxtYarnCount.Text.Trim) = False Then
            strWhere &= (IIf(String.IsNullOrEmpty(strWhere), "", cd) & "dblYarnCount = (@dblYarnCount)")
            cmd.Parameters.Add(New SqlClient.SqlParameter("@dblYarnCount", CDbl(Me.TxtYarnCount.Text.Trim)))
        End If

        If String.IsNullOrEmpty(Me.TxtMoistureRegain.Text.Trim) = False Then
            strWhere &= (IIf(String.IsNullOrEmpty(strWhere), "", cd) & "dblMoistureRegain = (@dblMoistureRegain)")
            cmd.Parameters.Add(New SqlClient.SqlParameter("@dblMoistureRegain", CDbl(Me.TxtMoistureRegain.Text.Trim)))
        End If

        If Me.CboWarehouseID.SelectedIndex > -1 Then
            strWhere &= (IIf(String.IsNullOrEmpty(strWhere), "", cd) & "intWarehouseID = (@intWarehouseID)")
            cmd.Parameters.Add(New SqlClient.SqlParameter("@intWarehouseID", CInt(Me.CboWarehouseID.SelectedValue)))
        End If

        If Me.ChkDeliveryDate.Checked Then
            strWhere &= (IIf(String.IsNullOrEmpty(strWhere), "", cd) & "dtmDelivery = (@dtmDelivery)")
            cmd.Parameters.Add(New SqlClient.SqlParameter("@dtmDelivery", Me.dtmDeliveryDate.Value.Date))
        End If

  
        cmd.CommandText = "select " & strLotFields & " from tblLot where strStatus<>'Void' and " & IIf(String.IsNullOrEmpty(strWhere), "1=1", strWhere)
        'cmd.CommandText ="sp_QueryItem"  
        'cmd.CommandType = CommandType.StoredProcedure   
        tblQuery = SQLHelper.GetDataTable(cmd)
        BindDv(tblQuery)
    End Sub

自定义控件鼠标滑动动态效果-边框颜色

Imports System.DrawingPublic Class UserControl1    Private Sub UserControl1_MouseHover(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.MouseHover        Using g As Graphics = Graphics.FromHwnd(Me.Handle)            g.DrawRectangle(Pens.Blue, 0, 0, Me.Width - 1, Me.Height - 1)        End Using    End Sub    Private Sub UserControl1_MouseLeave(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.MouseLeave        Using g As Graphics = Graphics.FromHwnd(Me.Handle)            g.DrawRectangle(New Pen(Me.BackColor), 0, 0, Me.Width - 1, Me.Height - 1)        End Using    End SubEnd Class