DataGridView多列排序实现方法

为了在Windows Forms应用程序中实现DataGridView的多列排序，我们可以利用C#中的自定义比较器来处理排序逻辑。以下是具体的实现步骤和代码示例。

```csharp
using System;
using System.Collections;
using System.Windows.Forms;

public class Form1 : Form
{
private DataGridView dataGridView1 = new DataGridView();
private FlowLayoutPanel flowLayoutPanel1 = new FlowLayoutPanel();
private Button button1 = new Button();
private RadioButton radioButtOnAsc= new RadioButton();
private RadioButton radioButtOnDesc= new RadioButton();

[STAThread]
public static void Main()
{
Application.Run(new Form1());
}

public Form1()
{
AutoSize = true;
Text = "DataGridView 多列排序示例";

flowLayoutPanel1.FlowDirection = FlowDirection.TopDown;
flowLayoutPanel1.Location = new System.Drawing.Point(300, 0);
flowLayoutPanel1.AutoSize = true;

flowLayoutPanel1.Controls.Add(radioButtonAsc);
flowLayoutPanel1.Controls.Add(radioButtonDesc);
flowLayoutPanel1.Controls.Add(button1);

button1.Text = "排序";
radioButtonAsc.Text = "升序";
radioButtonDesc.Text = "降序";
radioButtonAsc.Checked = true;

Controls.Add(flowLayoutPanel1);
Controls.Add(dataGridView1);
}

protected override void OnLoad(EventArgs e)
{
PopulateDataGridView();
button1.Click += new EventHandler(Button1_Click);
base.OnLoad(e);
}

private void PopulateDataGridView()
{
dataGridView1.Size = new Size(300, 300);
dataGridView1.ColumnCount = 2;

dataGridView1.Columns[0].Name = "FirstName";
dataGridView1.Columns[1].Name = "LastName";
dataGridView1.Columns["FirstName"].HeaderText = "名";
dataGridView1.Columns["LastName"].HeaderText = "姓";
dataGridView1.Columns["FirstName"].SortMode = DataGridViewColumnSortMode.Programmatic;
dataGridView1.Columns["LastName"].SortMode = DataGridViewColumnSortMode.Programmatic;

dataGridView1.Rows.Add(new string[] { "Peter", "Parker" });
dataGridView1.Rows.Add(new string[] { "James", "Jameson" });
dataGridView1.Rows.Add(new string[] { "May", "Parker" });
dataGridView1.Rows.Add(new string[] { "Mary", "Watson" });
dataGridView1.Rows.Add(new string[] { "Eddie", "Brock" });
}

private void Button1_Click(object sender, EventArgs e)
{
if (radioButtonAsc.Checked)
{
dataGridView1.Sort(new RowComparer(SortOrder.Ascending));
}
else if (radioButtonDesc.Checked)
{
dataGridView1.Sort(new RowComparer(SortOrder.Descending));
}
}

private class RowComparer : IComparer
{
private int sortOrderModifier = 1;

public RowComparer(SortOrder sortOrder)
{
if (sortOrder == SortOrder.Descending)
{
sortOrderModifier = -1;
}
else if (sortOrder == SortOrder.Ascending)
{
sortOrderModifier = 1;
}
}

public int Compare(object x, object y)
{
DataGridViewRow row1 = (DataGridViewRow)x;
DataGridViewRow row2 = (DataGridViewRow)y;

int compareResult = String.Compare(
row1.Cells[1].Value.ToString(),
row2.Cells[1].Value.ToString());

if (compareResult == 0)
{
compareResult = String.Compare(
row1.Cells[0].Value.ToString(),
row2.Cells[0].Value.ToString());
}

return compareResult * sortOrderModifier;
}
}
}
```

### 参考资料
- [MSDN: DataGridView.Sort 方法](http://msdn.microsoft.com/en-us/library/ms171607(VS.80).aspx)
- [MSDN: 如何：对 Windows 窗体 DataGridView 控件中的数据进行排序](http://msdn.microsoft.com/zh-cn/library/ms171608(VS.80).aspx)
- [MSDN: DataGridViewColumnSortMode 枚举](http://msdn.microsoft.com/en-us/library/95scxcdy.aspx)
- [CodeProject: DataGridView 的多列排序](http://www.codeproject.com/KB/grid/multicolumn_sort.aspx)
- [MSDN 博客: DataGridView 排序技巧](http://blogs.msdn.com/jfoscoding/articles/494012.aspx)