Question

我知道这个问题已在c＃中得到解答，但当我尝试从c＃在线转换到vb.net时，我遇到了运行错误。

免责声明不我的代码

   string personName = txtPersonName.Text;
   int personAge = Convert.ToInt32(txtAge.Text);
   var opportunites =  from p in this.DataContext.Persons
                        select new
                        {
                            p.PersonID,
                            p.Name,
                            p.Age,
                            p.Gender
                        };

    if (personsID != 0)
        opportunites = opportunites.Where(p => p.PersonID == personID);

    if (personName != string.Empty)
        opportunites = opportunites.Where(p => p.Name.StartsWith(personName));

    if (personAge != 0)
        opportunites = opportunites.Where(p => p.Age == personAge);

有人可以帮我转换这段代码我认为它是c＃，但是我无法将其正确转换为vb.net我试过telerik 但没有运气。

我无法在我的if语句中调用/使用linq select new {}中的'p'。

Answer 1

只需选择所需的值即可。匿名类型隐含在vb

中

https://msdn.microsoft.com/en-us/library/bb384767.aspx

Dim personName As String = "Joe"
Dim personAge As Integer = Convert.ToInt32(5)
Dim opportunites = From p IN AspNetUsers
                   Select p.Id,
                          p.FirstName,
                          p.LastName

If (personAge <> 0)
    opportunites = From o In opportunites Where o.Id >= 10
End If

Answer 2

您似乎遇到两个问题：匿名类型和lambdas - 下面的转换应该澄清这些问题：选项推断

Dim personName As String = txtPersonName.Text
Dim personAge As Integer = Convert.ToInt32(txtAge.Text)
Dim opportunites = From p In Me.DataContext.Persons
    Select New With {
        Key p.PersonID,
        Key p.Name,
        Key p.Age,
        Key p.Gender
    }

If personsID <> 0 Then
    opportunites = opportunites.Where(Function(p) p.PersonID = personID)
End If

If personName <> String.Empty Then
    opportunites = opportunites.Where(Function(p) p.Name.StartsWith(personName))
End If

If personAge <> 0 Then
    opportunites = opportunites.Where(Function(p) p.Age = personAge)
End If

vb.net linq where子句用于多个搜索过滤器 - 相同的查询但不同的where子句

2 个答案: