泛型的排序问题

ゞ浴缸里的玫瑰 2021-12-23 03:13 222阅读 0赞

在实际应用中，遇到需要对泛型集合进行排序，感觉有点意思，给大家分享下。（代码粘贴到工程中改个namespace就可以用了）

VB.NET示例

HTML源码：

<%@ Page Language="vb" AutoEventWireup="false" Codebehind="ListSort.aspx.vb" Inherits="Saas.Demo.Report.ListSort" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "[http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd][http_www.w3.org_TR_xhtml1_DTD_xhtml1-transitional.dtd]">  
<html xmlns="[http://www.w3.org/1999/xhtml][http_www.w3.org_1999_xhtml]">  
<head id="Head1" runat="server">  
<title>无标题页</title>  
</head>  
<body>  
<form id="form1" runat="server">  
<asp:DropDownList ID="CBOsortproperty" runat="server">  
<asp:ListItem Selected="True" Text="Birth" Value="2"></asp:ListItem>  
<asp:ListItem Text="ID" Value="0"></asp:ListItem>  
<asp:ListItem Text="Name" Value="1"></asp:ListItem>  
</asp:DropDownList>  
<asp:DropDownList ID="CBOsortorder" runat="server">  
<asp:ListItem Selected="True" Text="降序" Value="1"></asp:ListItem>  
<asp:ListItem Text="升序" Value="0"></asp:ListItem>  
</asp:DropDownList>  
<div>  
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False">  
<Columns>  
<asp:BoundField DataField="ID" HeaderText="ID" />  
<asp:BoundField DataField="Name" HeaderText="Name" />  
<asp:BoundField DataField="Birth" HeaderText="Birth" />  
</Columns>  
</asp:GridView>  
</div>  
<asp:Button ID="Button1" runat="server" Text="排序" />  
<asp:Button ID="Button2" runat="server" Text="恢复" />  
</form>  
</body>  
</html>

Code Behind：

Imports System.Collections

Partial Public Class ListSort  
Inherits System.Web.UI.Page

Protected Sub Page\_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load  
Dim lst As New List(Of Info)  
lst.Add(New Info(1, "Tim", "1975-11-20"))  
lst.Add(New Info(3, "Bob", "1978-11-20"))  
lst.Add(New Info(2, "Ben", "2005-11-20"))  
lst.Add(New Info(5, "Alston", "1995-11-20"))  
lst.Add(New Info(4, "Thoms", "2001-11-20"))

Me.GridView1.DataSource = lst  
Me.GridView1.DataBind()  
End Sub  
''' <summary>  
''' 排序  
''' </summary>  
''' <param name="sender"></param>  
''' <param name="e"></param>  
''' <remarks></remarks>  
Protected Sub Button1\_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click  
Dim lst As New List(Of Info)  
lst.Add(New Info(1, "Tim", "1975-11-20"))  
lst.Add(New Info(3, "Bob", "1978-11-20"))  
lst.Add(New Info(2, "Ben", "2005-11-20"))  
lst.Add(New Info(5, "Alston", "1995-11-20"))  
lst.Add(New Info(4, "Thoms", "2001-11-20"))

Dim c As CompareType  
Select Case CBOsortproperty.SelectedValue  
Case "2"  
c = New CompareType(CompareType.CompareType.Birth)  
Case "0"  
c = New CompareType(CompareType.CompareType.ID)  
Case "1"  
c = New CompareType(CompareType.CompareType.Name)  
Case Else  
c = New CompareType(CompareType.CompareType.Birth)  
End Select

lst.Sort(c)  
If CBOsortorder.SelectedValue.Equals("1") Then  
lst.Reverse()  
End If  
Me.GridView1.DataSource = lst  
Me.GridView1.DataBind()  
End Sub  
''' <summary>  
''' 恢复  
''' </summary>  
''' <param name="sender"></param>  
''' <param name="e"></param>  
''' <remarks></remarks>  
Protected Sub Button2\_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click  
Dim lst As New List(Of Info)  
lst.Add(New Info(1, "Tim", "1975-11-20"))  
lst.Add(New Info(3, "Bob", "1978-11-20"))  
lst.Add(New Info(2, "Ben", "2005-11-20"))  
lst.Add(New Info(5, "Alston", "1995-11-20"))  
lst.Add(New Info(4, "Thoms", "2001-11-20"))

Me.GridView1.DataSource = lst  
Me.GridView1.DataBind()  
End Sub  
Public Class Info  
Public Sub New(ByVal i As Integer, ByVal n As String, ByVal b As DateTime)  
Me.ID = i  
Me.Name = n  
Me.Birth = b  
End Sub

Private \_id As Integer  
Private \_name As String  
Private \_birth As DateTime

Public Property ID() As Integer  
Get  
Return \_id  
End Get  
Set(ByVal value As Integer)  
\_id = value  
End Set  
End Property  
Public Property Name() As String  
Get  
Return \_name  
End Get  
Set(ByVal value As String)  
\_name = value  
End Set  
End Property  
Public Property Birth() As DateTime  
Get  
Return \_birth  
End Get  
Set(ByVal value As DateTime)  
\_birth = value  
End Set  
End Property  
''' <summary>  
''' 按指定属性比较的函数  
''' </summary>  
''' <param name="x">比较对象</param>  
''' <param name="y">比较对象</param>  
''' <param name="type">属性</param>  
''' <returns>1:x>y;0:x=y;-1:y>x</returns>  
''' <remarks>静态函数Shared Shadows Function</remarks>  
Public Shared Shadows Function CompareByType(ByVal x As Info, ByVal y As Info, ByVal type As CompareType.CompareType) As Integer  
Select Case type  
Case CompareType.CompareType.ID  
Return x.ID.CompareTo(y.ID)  
Case CompareType.CompareType.Name  
Return x.Name.CompareTo(y.Name)  
Case CompareType.CompareType.Birth  
Return x.Birth.CompareTo(y.Birth)  
End Select  
End Function  
End Class

Class CompareType  
Implements IComparer(Of Info) '继承比较器接口IComparer

Public Sub New()  
Me.ComType = CompareType.Birth  
End Sub  
Public Sub New(ByVal ct As CompareType)  
Me.ComType = ct  
End Sub

Public Enum CompareType  
ID  
Name  
Birth  
End Enum

Private \_comType As CompareType

Public Property ComType() As CompareType  
Get  
Return \_comType  
End Get  
Set(ByVal value As CompareType)  
\_comType = value  
End Set  
End Property  
''' <summary>  
''' 设定排序属性  
''' </summary>  
''' <param name="ct"></param>  
''' <remarks></remarks>  
Public Sub SetCompareType(ByVal ct As CompareType)  
Me.ComType = ct  
End Sub  
''' <summary>  
''' 比较函数  
''' </summary>  
''' <param name="x">比较对象</param>  
''' <param name="y">比较对象</param>  
''' <returns>1:x>y;0:x=y;-1:y>x</returns>  
''' <remarks>实现接口的Compare方法</remarks>  
Public Function Compare(ByVal x As Info, ByVal y As Info) As Integer Implements System.Collections.Generic.IComparer(Of Info).Compare  
If x Is Nothing Then  
If y Is Nothing Then  
Return 0  
Else  
Return -1  
End If  
ElseIf y Is Nothing Then  
Return 1  
Else  
Return Info.CompareByType(x, y, ComType)  
End If  
End Function  
End Class

End Class

C\#.NET示例

HTML源码：

<%@ Page Language="C\#" AutoEventWireup="true" CodeBehind="ListSort.aspx.cs" Inherits="CSharpTest.ListSort" %>  
<html xmlns="[http://www.w3.org/1999/xhtml][http_www.w3.org_1999_xhtml]" >  
<head runat="server">  
<title>泛型排序</title>  
</head>  
<body>  
<form id="form1" runat="server">  
<asp:DropDownList ID="CBOsortproperty" runat="server">  
<asp:ListItem Selected="True" Text="Birthday" Value="2"></asp:ListItem>  
<asp:ListItem Text="ID" Value="0"></asp:ListItem>  
<asp:ListItem Text="Name" Value="1"></asp:ListItem>  
</asp:DropDownList>  
<asp:DropDownList ID="CBOsortorder" runat="server">  
<asp:ListItem Selected="True" Text="降序" Value="1"></asp:ListItem>  
<asp:ListItem Text="升序" Value="0"></asp:ListItem>  
</asp:DropDownList>  
<div>  
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False">  
<Columns>  
<asp:BoundField DataField="ID" HeaderText="ID" />  
<asp:BoundField DataField="Name" HeaderText="Name" />  
<asp:BoundField DataField="Birthday" HeaderText="Birthday" />  
</Columns>  
</asp:GridView>  
</div>  
<asp:Button ID="Button1" runat="server" Text="排序" OnClick="Button1\_Click" />  
<asp:Button ID="Button2" runat="server" Text="恢复" OnClick="Button2\_Click" />  
</form>  
</body>  
</html>  
Code Behind:

using System;  
using System.Data;  
using System.Configuration;  
using System.Collections;  
using System.Web;  
using System.Web.Security;  
using System.Web.UI;  
using System.Web.UI.WebControls;  
using System.Web.UI.WebControls.WebParts;  
using System.Web.UI.HtmlControls;  
using System.Collections.Generic;

namespace CSharpTest  
\{  
public partial class ListSort : System.Web.UI.Page  
\{  
protected void Page\_Load(object sender, EventArgs e)  
\{  
GridView1.DataSource = InitList();  
GridView1.DataBind();  
\}  
/// <summary>  
/// 初始化泛型集合  
/// </summary>  
/// <returns></returns>  
private List<Info> InitList()  
\{  
List<Info> lst = new List<Info>();

lst.Add(new Info(2, "T", "1985"));  
lst.Add(new Info(5, "B", "1856"));  
lst.Add(new Info(1, "A", "1997"));  
lst.Add(new Info(4, "Z", "2009"));  
lst.Add(new Info(3, "G", "2000"));

return lst;  
\}  
/// <summary>  
/// 排序  
/// </summary>  
/// <param name="sender"></param>  
/// <param name="e"></param>  
protected void Button1\_Click(object sender, EventArgs e)  
\{  
List<Info> lst = InitList();

//创建比较器实例  
CompareType c;  
switch (CBOsortproperty.SelectedValue)  
\{  
case "0":  
c = new CompareType(CompareType.CompType.ID);  
break;  
case "1":  
c = new CompareType(CompareType.CompType.Name);  
break;  
case "2":  
c = new CompareType(CompareType.CompType.Birthday);  
break;  
default:  
c = new CompareType(CompareType.CompType.Birthday);  
break;  
\}  
lst.Sort(c);

if (CBOsortorder.SelectedValue.Equals("1"))  
\{  
lst.Reverse(); //泛型排序默认为升序,若要求降序排序,需调用此方法  
\}

GridView1.DataSource = lst;  
GridView1.DataBind();  
\}  
/// <summary>  
/// 恢复  
/// </summary>  
/// <param name="sender"></param>  
/// <param name="e"></param>  
protected void Button2\_Click(object sender, EventArgs e)  
\{  
GridView1.DataSource = InitList();  
GridView1.DataBind();  
\}  
\}

public class Info  
\{  
//构造函数  
public Info(int i,string n,string b)  
\{  
ID = i;  
Name = n;  
Birthday = b;  
\}  
//Property  
private int \_ID;  
public int ID  
\{  
get \{ return \_ID; \}  
set \{ \_ID = value; \}  
\}  
private string \_Name;  
public string Name  
\{  
get \{ return \_Name; \}  
set \{ \_Name = value; \}  
\}  
private string \_Birthday;  
public string Birthday  
\{  
get \{ return \_Birthday; \}  
set \{ \_Birthday = value; \}  
\}  
/// <summary>  
/// 静态函数,实现比较功能,便于在类CompareType中调用  
/// </summary>  
/// <param name="x">比较对象</param>  
/// <param name="y">比较对象</param>  
/// <param name="type">排序属性(枚举类型)</param>  
/// <returns>1:x>y;0:x==y;-1:y>x</returns>  
public static int CompareByType(Info x,Info y,CompareType.CompType type)  
\{  
switch (type)  
\{  
case CompareType.CompType.ID:  
return x.ID.CompareTo(y.ID);  
case CompareType.CompType.Name:  
return x.Name.CompareTo(y.Name);  
case CompareType.CompType.Birthday:  
return x.Birthday.CompareTo(y.Birthday);  
default:  
return 0;  
\}  
\}  
\}  
/// <summary>  
/// 实现比较器接口IComparer  
/// </summary>  
public class CompareType:IComparer<Info>  
\{  
public CompareType()  
\{  
ComType = CompareType.CompType.Birthday;  
\}

public CompareType(CompType c)  
\{  
ComType = c;  
\}

public enum CompType  
\{  
ID,  
Name,  
Birthday  
\}

private CompType \_ComType;

public CompType ComType  
\{  
get \{ return \_ComType; \}  
set \{ \_ComType = value; \}  
\}  
/// <summary>  
/// 实现IComparer.Compare()  
/// </summary>  
/// <param name="x"></param>  
/// <param name="y"></param>  
/// <returns></returns>  
public int Compare(Info x, Info y)  
\{  
if (x == null)  
\{  
if (y == null)  
\{  
return 0;  
\}  
else  
\{  
return -1;  
\}  
\}  
else if (y == null)  
\{  
return 1;  
\}  
else  
\{  
return Info.CompareByType(x,y,ComType); //调用类Info的静态函数CompareByType  
\}  
\}  
\}  
\}

转载于:https://www.cnblogs.com/guoxiaowen/archive/2009/02/03/1383258.html

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