试一试这个看看：
Dim dr As row =tables("业务").Current
Dim ColNames() AS String = "项目名称,业务类型,基准日期,作业日期,标的额,鉴定人员,报告,任务人".Split(",")
For Each ColName AS String In ColNames
    if dr.IsNull(ColName)
        MessageBox.Show("请详细完整地填写  \'" & Colname & _
        "\' !","存盘失败",MessageBoxButtons.OK,MessageBoxIcon.Warning) \'提示用户
        return 
    end if
Next  \'8
if  Forms("业务一").Controls("RadioButton2").Checked=false And _
    Forms("业务一").Controls("RadioButton1").Checked=false  Then
    MessageBox.Show("请选择委托类别!","存盘失败", _
    MessageBoxButtons.OK,MessageBoxIcon.Warning) \'提示用户
ElseIf  Forms("业务一").Controls("RadioButton1").Checked=true and _
    dr.isnull("委托单位") then
    MessageBox.Show("请选择委托或联系单位!","存盘失败", _
    MessageBoxButtons.OK,MessageBoxIcon.Warning) \'提示用户
ElseIf dr("业务类型")="交通事故" then
    If  dr.IsNull("当事人") or dr.IsNull("车辆型号") or dr.IsNull("图片") Then
        Dim ColNames1() AS String = "当事人,车辆型号,图片".Split(",")
        For Each ColName1 as String In ColNames1
            If dr.isnull(ColName1) Then
                MessageBox.Show("请详细完整地填写  \'" & Colname1 & _
                "\' !","存盘失败",MessageBoxButtons.OK,MessageBoxIcon.Warning) \'提示用户
            End If
        Next
    End IF
ElseIf  dr.IsNull("当事人") Then
    If dr("业务类型")="房地产认证" Or dr("业务类型")="非刑事案件" Or _
        dr("业务类型")="其它价格认证"  then
        MessageBox.Show("请详细完整地填写当事人!","存盘失败", _
        MessageBoxButtons.OK,MessageBoxIcon.Warning) \'提示用户
    End IF
ElseIf Forms("业务一").Controls("RadioButton3").Checked=false And _
    Forms("业务一").Controls("RadioButton4").Checked=false And _
    Forms("业务一").Controls("RadioButton5").Checked = False  then
    MessageBox.Show("请选择收费状态!","存盘失败", _
    MessageBoxButtons.OK,MessageBoxIcon.Warning) \'提示用户
Else
    DataTables("业务").Save()
    Tables("业务").AddNew(1)
    MessageBox.Show("保存成功! 继续~ ","存盘")
End If