Question

美好的一天我是vb.net的初学者和stackoverflow中的新手，我在Filter方法中遇到问题...
以下是我的代码：

Private Sub btnSearch_Click(sender As Object, e As EventArgs) Handles btnSearch.Click
Dim zCondition As String = ""

If txtrid.Text.Length > 0 Then zCondition = zCondition & "receiptID='" & txtrid.Text & "',"
If txtsid.Text.Length > 0 Then zCondition = zCondition & "stkID='" & txtsid.Text & "',"
If txtsname.Text.Length > 0 Then zCondition = zCondition & "stkName='" & txtsname.Text & "',"
If txtsprice.Text.Length > 0 Then zCondition = zCondition & "stkPrice='" & txtsprice.Text & "',"
If txtsquantity.Text.Length > 0 Then zCondition = zCondition & "quantity='" & txtsquantity.Text & "',"
If txtdate.Text.Length > 0 Then zCondition = zCondition & "dateTime='" & txtdate.Text & "',"
If txtcid.Text.Length > 0 Then zCondition = zCondition & "custID='" & txtcid.Text & "',"

zCondition = zCondition.Substring(0, zCondition.Length - 1)

Dim dv As DataView
dv = New DataView(DsSales1.Tables(0), zCondition, "type Desc", DataViewRowState.CurrentRows)
DataGridView1.DataSource = dv

End Sub

当我执行并测试代码时，它会给我一个错误Cannot find column type. ...
这条线似乎有错误：

dv = New DataView(DsSales1.Tables(0), zCondition, "type Desc", DataViewRowState.CurrentRows)

任何人都可以帮我解决这个问题并向我解释我遇到的问题是什么？谢谢。
抱歉我的英语不好：）

Answer 1

你的情况完全错了。你就是这样做的

Dim cond As New StringBuilder(1000)
cond.Append("1 = 1") ' now, you will never add extra 'AND', 'OR' etc. 1 is always 1
' if any text box below is missing data it will not hurt anything using this technique
' NOTE spaces in front of 'AND'
If txtrid.Text.Length > 0 Then cond.Append(" AND receiptID='" & txtrid.Text & "'") ' removed commas
If txtsid.Text.Length > 0 Then cond.Append(" AND stkID='" & txtsid.Text & "'")
If txtsname.Text.Length > 0 Then cond.Append(" AND stkName='" & txtsname.Text & "'")
If txtsprice.Text.Length > 0 Then cond.Append(" AND stkPrice='" & txtsprice.Text & "'")
If txtsquantity.Text.Length > 0 Then cond.Append(" AND quantity='" & txtsquantity.Text & "'")
If txtdate.Text.Length > 0 Then cond.Append(" AND dateTime='" & txtdate.Text & "'")
If txtcid.Text.Length > 0 Then cond.Append(" AND custID='" & txtcid.Text & "'") 


Dim dv As New DataView(DsSales1.Tables(0), cond.ToString(), "COL_NAME Desc", DataViewRowState.CurrentRows)

您的错误很可能是由order by引起的。您可能没有列“类型”

另一个问题是txtsid，txtsprice - 这是字符串吗？如果不是 - 你需要在你的条件下删除单引号。

Answer 2

在你的情况下，过滤器可能比我在这里看到的更容易......

  ' Create a DataView 
    Dim dv As New DataView(DsSales1.Tables(0))

    ' Filter by an expression. 
    dv.RowFilter = zCondition

同样在您的支票中，您可以执行：zCondition &=添加字符串...在另一个注意事项中，在添加其他字符串后，删除**,**后，使用**AND**

你的if也可以归结为这个......

    If txtrid.Text.Length > 0 Then zCondition &= "receiptID='" & txtrid.Text & "'"
    If txtsid.Text.Length > 0 AndAlso txtrid.Text.Length > 0 Then zCondition &= "AND stkID='" & txtsid.Text & "'" Else zCondition &= "stkID='" & txtsid.Text & "'"
    If txtsname.Text.Length > 0 AndAlso txtsid.Text.Length > 0 Then zCondition &= "AND stkName='" & txtsname.Text & "'" Else zCondition &= "stkName='" & txtsname.Text & "'"

MrCodexer

Answer 3

这就是我所做的:) 抱歉，我忘了提及我也将**,**更改为** AND **

Private Sub btnSearch_Click(sender As Object, e As EventArgs) Handles btnSearch.Click

    Dim zCondition As String = ""
    If txtrid.Text.Length > 0 Then zCondition = zCondition & "receiptID='" & txtrid.Text & "' AND "
    If txtsid.Text.Length > 0 Then zCondition = zCondition & "stkID='" & txtsid.Text & "' AND "
    If txtsname.Text.Length > 0 Then zCondition = zCondition & "stkName='" & txtsname.Text & "' AND "
    If txtsprice.Text.Length > 0 Then zCondition = zCondition & "stkPrice='" & txtsprice.Text & "' AND "
    If txtsquantity.Text.Length > 0 Then zCondition = zCondition & "quantity='" & txtsquantity.Text & "' AND "
    If txtdate.Text.Length > 0 Then zCondition = zCondition & "dateTime='" & txtdate.Text & "' AND "
    If txtcid.Text.Length > 0 Then zCondition = zCondition & "custID='" & txtcid.Text & "' AND "
    zCondition = zCondition.Substring(0, zCondition.Length - 5)

    Dim dv As DataView
    dv = New DataView(DsSales1.Tables(0), zCondition, "receiptID Desc", DataViewRowState.CurrentRows)
    DataGridView1.DataSource = dv

End Sub

如何在datagridview上应用Filter？

3 个答案: