如何在 vb.net 中使用 IEquatable<T> 进行现场匹配 Proper 和 lower

Question

如何解决lower和property的字段匹配，使得结果在DataGridView中成为一行，并且只更新数字。

我的代码有问题吗？请指导我。

我使用的方法有什么问题吗？

谢谢

下面是我使用的代码

Private Sub OnAddRecord(ByVal sender As Object, ByVal e As EventArgs) Handles btnAddProduct.Click
Dim new_product = New Product With {
                .Date = dtPicker.Value.ToShortDateString(),
                .Code = txtCode.Text,
                .Name = txtName.Text,
                .Quantity = npQuantity.Value
            }
Dim p = list.FirstOrDefault(Function(x) x = new_product)
            If p Is Nothing Then
                ' Product is not found. Add it to list.
                list.Add(new_product)
            Else
                ' Product is found. Update quantity.
                p.Quantity += new_product.Quantity
            End If
            dataGrid.Refresh() 'Required to reflect changes
        End Sub
    Friend Class Product
        Implements IEquatable(Of Product)

        Public Property [Date]() As String
        Public Property Code() As String
        Public Property Name() As String
        Public Property Quantity() As Decimal

        ' Overload == operator
        Public Shared Operator =(ByVal firstProduct As Product, ByVal secondProduct As Product) As Boolean
            ' Check for null on left side.
            If Object.ReferenceEquals(firstProduct, Nothing) Then
                If Object.ReferenceEquals(secondProduct, Nothing) Then
                    ' null == null = true.
                    Return True
                End If
                ' Only the left side is null.
                Return False
            End If
            ' Equals handles case of null on right side.
            Return firstProduct.Equals(secondProduct)
        End Operator

        'Overload != operator (required when overloading == operator)
        Public Shared Operator <>(ByVal firstProduct As Product, ByVal secondProduct As Product) As Boolean
            Return Not (firstProduct = secondProduct)
        End Operator

        ' Implementing IEquatable<T> interface
        Public Overloads Function Equals(ByVal other As Product) As Boolean Implements IEquatable(Of Product).Equals
            ' If 'other' is null, return false.
            If Object.ReferenceEquals(other, Nothing) Then
                Return False
            End If

            ' Optimization for a common success case.
            If Object.ReferenceEquals(Me, other) Then
                Return True
            End If

            ' If run-time types are not exactly the same, return false.
            If Me.GetType() IsNot other.GetType() Then
                Return False
            End If

            ' Return true if the fields match.
            Return [Date] = other.Date AndAlso Code = other.Code AndAlso Name = other.Name
        End Function
    End Class

Answer 1

而不是比较

Name = other.Name

比较

String.Compare(Name, other.Name, ignoreCase:=True)

整行内容如下：

Return [Date] = other.Date AndAlso Code = other.Code AndAlso String.Compare(Name, other.Name, ignoreCase:=True)