如何在C＃中显示和排序列表？

Question

I have a List of "StudentRecords" which contain students and their test scores. For each student, I have their names, age, contact phone number, test scores, and the dates they took a test.

public class StudentRecord
{
       public String Name  { get; set; }
       public int Age  { get; set; }
       public String PhoneNum  { get; set; }
       public int TestScore1  { get; set; }
       public DateTime TestScore1Date  { get; set; }
}

List<StudentRecord> StudentList = new List<StudentRecord>();
dataGridView1.DataSource = StudentList;

I binded my List to a DataGridView control and am able to view the information just great. Now, I want to be able to sort the contents of the List by things like Name first, then scores, then age within the DataGrid control.

I found this: http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.columnheadermouseclick.aspx

which says the default behavior is to order the grid rows based on the clicked column header. However, this does not happen by default when I click. In fact, nothing happens when I click on the column header. Any idea what I might be doing wrong?

Answer 1

Unfortunately, this behavior is not available out-of-the-box with the DataGridView control. In order to use List<T> as the binding source and allow for column click sorting, then you need to handle the ColumnHeaderMouseClick event of the DataGridView , like this:

protected void dataGridView1_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
    // Get the information about the column clicked
    var strColumnName = dataGridView1.Columns[e.ColumnIndex].Name;
    SortOrder strSortOrder = getSortOrder(e.ColumnIndex);

    // Sort the list
    StudentList.Sort(new StudentComparer(strColumnName, strSortOrder));

    // Rebind to use sorted list
    dataGridView1.DataSource = null;
    dataGridView1.DataSource = StudentList;

    // Update user interface icon for sort order in column clicked
    dataGridView1.Columns[e.ColumnIndex].HeaderCell.SortGlyphDirection = strSortOrder;
}

private SortOrder getSortOrder(int columnIndex)
{
    if (dataGridView1.Columns[columnIndex].HeaderCell.SortGlyphDirection == SortOrder.None ||
        dataGridView1.Columns[columnIndex].HeaderCell.SortGlyphDirection == SortOrder.Descending)
    {
        dataGridView1.Columns[columnIndex].HeaderCell.SortGlyphDirection = SortOrder.Ascending;
        return SortOrder.Ascending;
    }
    else
    {
        dataGridView1.Columns[columnIndex].HeaderCell.SortGlyphDirection = SortOrder.Descending;
        return SortOrder.Descending;
    }
}

public class StudentComparer : IComparer<StudentRecord>
{
    string memberName = String.Empty;
    SortOrder sortOrder = SortOrder.None;

    public StudentComparer(string strMemberName, SortOrder sortingOrder)
    {
        memberName = strMemberName;
        sortOrder = sortingOrder;
    }

    public int Compare(StudentRecord student1, StudentRecord student2)
    {
        int returnValue = 1;
        switch (memberName)
        {
            case "Name" :
                if (sortOrder == SortOrder.Ascending)
                {
                    returnValue = student1.Name.CompareTo(student2.Name);
                }
                else
                {
                    returnValue = student2.Name.CompareTo(student1.Name);
                }
                break;
            case "Age":
                if (sortOrder == SortOrder.Ascending)
                {
                    returnValue = student1.Age.CompareTo(student2.Age);
                }
                else
                {
                    returnValue = student2.Age.CompareTo(student1.Age);
                }
                break;
            case "PhoneNum":
                if (sortOrder == SortOrder.Ascending)
                {
                    returnValue = student1.PhoneNum.CompareTo(student2.PhoneNum);
                }
                else
                {
                    returnValue = student2.PhoneNum.CompareTo(student1.PhoneNum);
                }
                break;
            case "TestScore1":
                if (sortOrder == SortOrder.Ascending)
                {
                    returnValue = student1.TestScore1.CompareTo(student2.TestScore1);
                }
                else
                {
                    returnValue = student2.TestScore1.CompareTo(student1.TestScore1);
                }
                break;
            case "TestScore1Date":
                if (sortOrder == SortOrder.Ascending)
                {
                    returnValue = student1.TestScore1Date.CompareTo(student2.TestScore1Date;
                }
                else
                {
                    returnValue = student2.TestScore1Date.CompareTo(student1.TestScore1Date);
                }
                break;
            default:
                if (sortOrder == SortOrder.Ascending)
                {
                    returnValue = Student1.Name.CompareTo(Student2.Name);
                }
                else
                {
                    returnValue = Student2.Name.CompareTo(Student1.Name);
                }
                break;
        }
        return returnValue;
    }
}

Note: The default sorting criteria is Name .

Answer 2

You must implement a custom code to datagrid can sort the data. means of that document about default behavior is that when you double click the grid in design mode, VS generate a method to handle this event. read this : Sort DataGrid

Answer 3

First I think you need to implement that behavior, I doubt it's out of the box.

Second, you could easily sort your objects using LINQ , and have nice groups etc.

Now, if you would like to sort them by different criteria according to clicks, you might need to go with a ListView, and then you would be able to have filters on that, but this is usually a bit longer to do. Here's the MSDN page and at the bottom you have a link to how to sort on header clicked ...