简单需求
实现分页。而且当分页数量较大时，最多只显示自定义的页数。（比如只显示10页）
Paging
BaseDto.cs
/// <summary>
/// base request
/// </summary>
[Serializable]
public abstract class BaseDto
{
//tostring();
public static string ToString(ArrayList arrayList)
{
int count = arrayList.Count;
if (count == 0)
{
return "[]";
}
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.Append("[");
foreach (object obj in arrayList)
{
stringBuilder.Append(obj).Append(",").Append(" ");
}
//Remove the last , append;
stringBuilder.Remove(stringBuilder.Length-2, 2);
stringBuilder.Append("]");
return stringBuilder.ToString();
}
}
BaseRequest.cs
/// <summary>
/// Pageable request.
/// </summary>
public class PageableRequest : BaseDto
{
/// <summary>
/// The page number.
/// </summary>
private int pageNum;
/// <summary>
/// The size of the page.
/// </summary>
private int pageSize = 10;
/// <summary>
/// The order by.
/// </summary>
private String orderBy;
public int PageNum
{
get
{
return pageNum;
}
set
{
pageNum = value;
}
}
public int PageSize
{
get
{
return pageSize;
}
set
{
pageSize = value;
}
}
public string OrderBy
{
get
{
return orderBy;
}
set
{
orderBy = value;
}
}
}
BaseResponse.cs
public class BaseResponse : BaseDto
{
/// <summary>
/// The resp code.
/// </summary>
private String respCode;
/// <summary>
/// The message.
/// </summary>
private String msg;
public string RespCode
{
get
{
return respCode;
}
set
{
respCode = value;
}
}
public string Msg
{
get
{
return msg;
}
set
{
msg = value;
}
}
}
PageableResponse.cs
/**
* <p/>
* 新增分页的多项属性，主要参考:http://bbs.csdn.net/topics/360010907
*
* @author liuzh/abel533/isea533
* @version 3.3.0
* @since 3.2.2
* 项目地址 : http://git.oschina.net/free/Mybatis_PageHelper
*/
public class PageableResponse<T> : BaseResponse
{
#region base fields
//当前页
private int pageNum;
//每页的数量
private int pageSize;
//当前页的数量
private int size;
//由于startRow和endRow不常用，这里说个具体的用法
//可以在页面中"显示startRow到endRow 共size条数据"
//当前页面第一个元素在数据库中的行号
private int startRow;
//当前页面最后一个元素在数据库中的行号
private int endRow;
//总记录数
private long total;
//总页数
private int pages;
//结果集
private List<T> list;
//前一页
private int prePage;
//下一页
private int nextPage;
//是否为第一页
private bool isFirstPage = false;
//是否为最后一页
private bool isLastPage = false;
//是否有前一页
private bool hasPreviousPage = false;
//是否有下一页
private bool hasNextPage = false;
//导航页码数
private int navigatePages;
//所有导航页号
private int[] navigatepageNums;
//导航条上的第一页
private int navigateFirstPage;
//导航条上的最后一页
private int navigateLastPage;
#endregion
#region
public int PageNum
{
get
{
return pageNum;
}
}
public int PageSize
{
get
{
return pageSize;
}
}
public int Size
{
get
{
return size;
}
}
public int StartRow
{
get
{
return startRow;
}
}
public int EndRow
{
get
{
return endRow;
}
}
public long Total
{
get
{
return total;
}
}
public int Pages
{
get
{
return pages;
}
}
public List<T> List
{
get
{
return list;
}
}
public int PrePage
{
get
{
return prePage;
}
}
public int NextPage
{
get
{
return nextPage;
}
}
public bool IsFirstPage
{
get
{
return isFirstPage;
}
}
public bool IsLastPage
{
get
{
return isLastPage;
}
}
public bool HasPreviousPage
{
get
{
return hasPreviousPage;
}
}
public bool HasNextPage
{
get
{
return hasNextPage;
}
}
public int NavigatePages
{
get
{
return navigatePages;
}
}
public int[] NavigatepageNums
{
get
{
return navigatepageNums;
}
}
public int NavigateFirstPage
{
get
{
return navigateFirstPage;
}
}
public int NavigateLastPage
{
get
{
return navigateLastPage;
}
}
#endregion
PageableResponse(List<T> list, int navigatePages)
{
int count = list.Count;
if (list is ICollection)
{
this.pageNum = 1;
this.pageSize = count;
this.pages = 1;
this.list = list;
this.size = count;
this.total = count;
this.startRow = 0;
this.endRow = count > 0 ? count - 1 : 0;
}
if (list is ICollection)
{
this.navigatePages = navigatePages;
//计算导航页
calcNavigatepageNums();
//计算前后页，第一页，最后一页
calcPage();
//判断页面边界
judgePageBoudary();
}
}
public PageableResponse(List<T> list) : this(list, 8)
{
}
/**
* 计算导航页
*/
private void calcNavigatepageNums()
{
//当总页数小于或等于导航页码数时
if (pages <= navigatePages)
{
navigatepageNums = new int[pages];
for (int i = 0; i < pages; i++)
{
navigatepageNums[i] = i + 1;
}
}
else { //当总页数大于导航页码数时
navigatepageNums = new int[navigatePages];
int startNum = pageNum - navigatePages / 2;
int endNum = pageNum + navigatePages / 2;
if (startNum < 1)
{
startNum = 1;
//(最前navigatePages页
for (int i = 0; i < navigatePages; i++)
{
navigatepageNums[i] = startNum++;
}
}
else if (endNum > pages)
{
endNum = pages;
//最后navigatePages页
for (int i = navigatePages - 1; i >= 0; i--)
{
navigatepageNums[i] = endNum--;
}
}
else {
//所有中间页
for (int i = 0; i < navigatePages; i++)
{
navigatepageNums[i] = startNum++;
}
}
}
}
/**
* 计算前后页，第一页，最后一页
*/
private void calcPage()
{
if (navigatepageNums != null && navigatepageNums.Length > 0)
{
navigateFirstPage = navigatepageNums[0];
navigateLastPage = navigatepageNums[navigatepageNums.Length - 1];
if (pageNum > 1)
{
prePage = pageNum - 1;
}
if (pageNum < pages)
{
nextPage = pageNum + 1;
}
}
}
/**
* 判定页面边界
*/
private void judgePageBoudary()
{
isFirstPage = pageNum == 1;
isLastPage = pageNum == pages;
hasPreviousPage = pageNum > 1;
hasNextPage = pageNum < pages;
}
public override string ToString()
{
return string.Format("[PageableResponse: pageNum={0}, pageSize={1}, size={2}, startRow={3}, endRow={4}, total={5}, pages={6}, list={7}, prePage={8}, nextPage={9}, isFirstPage={10}, isLastPage={11}, hasPreviousPage={12}, hasNextPage={13}, navigatePages={14}, navigatepageNums={15}, navigateFirstPage={16}, navigateLastPage={17}, PageNum={18}, PageSize={19}, Size={20}, StartRow={21}, EndRow={22}, Total={23}, Pages={24}, List={25}, PrePage={26}, NextPage={27}, IsFirstPage={28}, IsLastPage={29}, HasPreviousPage={30}, HasNextPage={31}, NavigatePages={32}, NavigatepageNums={33}, NavigateFirstPage={34}, NavigateLastPage={35}]", pageNum, pageSize, size, startRow, endRow, total, pages, list, prePage, nextPage, isFirstPage, isLastPage, hasPreviousPage, hasNextPage, navigatePages, navigatepageNums, navigateFirstPage, navigateLastPage, PageNum, PageSize, Size, StartRow, EndRow, Total, Pages, List, PrePage, NextPage, IsFirstPage, IsLastPage, HasPreviousPage, HasNextPage, NavigatePages, NavigatepageNums, NavigateFirstPage, NavigateLastPage);
}
}
简单测试
- ExeTest.cs
class ExeTest
{
static void Main(string[] args)
{
Console.Write("");
System.Collections.Generic.List<string> stringList = new System.Collections.Generic.List<string>();
stringList.Add("One");
stringList.Add("two");
PageableResponse<string> response = new PageableResponse<string>(stringList);
Console.WriteLine("response : {0}", response);
}
}
- result
response : [PageableResponse: pageNum=1, pageSize=2, size=2, startRow=0, endRow=1, total=2, pages=1, list=System.Collections.Generic.List`1[System.String], prePage=0, nextPage=0, isFirstPage=True, isLastPage=True, hasPreviousPage=False, hasNextPage=False, navigatePages=8, navigatepageNums=System.Int32[], navigateFirstPage=1, navigateLastPage=1, PageNum=1, PageSize=2, Size=2, StartRow=0, EndRow=1, Total=2, Pages=1, List=System.Collections.Generic.List`1[System.String], PrePage=0, NextPage=0, IsFirstPage=True, IsLastPage=True, HasPreviousPage=False, HasNextPage=False, NavigatePages=8, NavigatepageNums=System.Int32[], NavigateFirstPage=1, NavigateLastPage=1]
备注：
1、在C#中Collection和Array无法直接打印出内容。需要特殊处理。为此将在 BaseDto.cs 中添加反射 ToString()，并处理此特殊情况。
2、PageSize 在查询记录如果少于分页大小时是错误的。实际应用中，PageSize是前端传过来的。不需要后台再次反馈回去。
