C# cannot convert int to string

Question

var query = from s in student
            select new ListItem
            {
                ID = s.studentId, 
                Name = s.studentName
            };

When I tried to execute the code I got the error

/ /Cannot implicitly convert type 'int' (studentId) to 'string' (ID).

Is there anyway I can achieve this?

Answer 1

Did you try 'ToString()'?

var studentId = s.studentId.ToString();
var query = from s in student select new ListItem { ID = studentId, Name = s.studentName };

Answer 2

Since you are using LINQ to Entities ToString won't work for you instead you will have to try out

SqlFunctions.StringConvert((double)s.studentId) //since there is no overload for int

Check this out Sql Functions

Answer 3

使用var类型创建一个新变量，并将studentid的值赋给该变量，并在linq中使用新变量

Answer 4

The ListItem does not contain an ID property. Try using one of its constructors;

var query = from s in student select new ListItem(s.studentName, s.studentId.ToString());

Answer 5

Use Convert.ToString() method.....Convert.ToString(obj) doesn't need to presume the object is not null (as it is a static method on the Convert class), but instead will return String.Empty if it is null.....

 var query = from s in student
                        select new ListItem
                        {
                            ID = Convert.ToString(s.studentId),
                            Name = s.studentName
                        };