Question

我对我的代码有一些疑问。我是VB2005的初学者，我想从我的txtISBNInfo＆amp; amp;中添加一些我的dgCart（DataGrid）项目。 txtTitleInfo（文本框）。加上它后，itemx必须限制为3，而dgCart（DataGrid）不应包含任何加倍或重复的ov项。我该怎么办？在我的for each中，它将确定它是否存在，然后只有在确定它不存在之后才添加新行。我的意思是......在这里，我向你展示了我的代码，但遗憾的是它不起作用......

Private Sub btnAddToCart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddToCart.Click

    Dim IsFound As Boolean = False

    Dim Count As Integer = dgCart.Rows.Count

    For Each dgvRow As DataGridViewRow In dgCart.Rows

        If dgvRow.Cells("clmISBN").Value.ToString = txtISBNInfo.Text Then
            IsFound = True
            'at this point you can actually exit for because you have the info you need.

        End If
    Next

    If IsFound Then
        dgCart.Rows.Add(txtISBNInfo.Text, txtTitleInfo.Text)
    Else
        MsgBox("Already in list!")
    End If

End Sub

Answer 1

我认为你几乎已经拥有了它，但你在最后交换了if语句

Private Sub btnAddToCart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddToCart.Click
    ''//Set a flag saying that we have not found the row yet
    Dim IsFound As Boolean = False

    ''//Loop through each row
    For Each dgvRow As DataGridViewRow In dgCart.Rows
        ''//Compare the cell to our inputed
        If dgvRow.Cells("clmISBN").Value.ToString = txtISBNInfo.Text Then
            ''//Flag the we found the item
            IsFound = True
            ''//No need to loop through the remaining rows, exit the loop
            Exit For    
        End If
    Next

    ''If the item was found in the datagrid
    If IsFound Then
        MsgBox("Already in list!")
    Else ''//Otherwise
        ''//Add it
        dgCart.Rows.Add(txtISBNInfo.Text, txtTitleInfo.Text)
    End If
End Sub

我使用DataGrid查询了我的代码n VB2005

1 个答案: