jquery.easyui使用详解，和遇到的问题，提供大家在使用的时候少走弯路（二）

上次解释了几个易犯错的地方，当然对于大神们那都是小菜一碟了，今天来说说后台请求数据，分页，返回json数据

废话不多说献上代码

private string QueryList(ArrayList arrayList)
{
//ArrayList ret = new ArrayList();
string order = this.Request.Form["order"];
string sort = this.Request.Form["sort"];
string rows = this.Request.Form["rows"];
string page = this.Request.Form["page"];
//page=1&rows=10&sort=UserName&order=desc
int iSortIndex, iPage, iRows;
string[] colums = new string[] {  "moveid", "daytime", "outsite", "insite", "inputman", "handleman", "outdate", "outid", "availability", "invaliddate", "status", "preconcert", "checked", "chkdate", "fin_checked", "remark", "used", "deleted"};
//if (!int.TryParse(sidx, out iSortIndex))
//{
//    iSortIndex = -1;
//}
iSortIndex = 1;
if (!int.TryParse(page, out iPage))
{
iPage = 1;
}
if (!int.TryParse(rows, out iRows) || iRows > 100 || iRows <= 0)
{
iRows = 20;
}
int total = 0;
//传入表名
JGDataQuery gq = new JGDataQuery("move");
//传入搜索条件
if (!string.IsNullOrEmpty(Request.Form["IdOrName"]))
{
if (Erp.Common.Verify.IsNumber(Request.Form["IdOrName"]))
{
gq.AddQueryParam("moveid", Request.Form["IdOrName"]);
}
}
　　　　　　
DataTable dt = gq.GetListByPage(colums, iPage, iRows, 1, sort,out total);
　　　　　//返回json
return Erp.Common.ToEasyJson.TableToJson(dt,total);

}

上面查询数据是封装了一个类，包括查询条件和数据分页sql,当然用存储过程是最好，最快的啦，但是系统关联表太多，为了不麻烦的频繁改，就拼sql啦，为了扩展方便嘛，偷偷懒

public class JGDataQuery
{

public string TableName { get; private set; }
string sqlWhere;
List<SqlParameter> sqlParaList = new List<SqlParameter>();
public JGDataQuery(string tableName)
{
//
//TODO: 在此处添加构造函数逻辑
//
if (string.IsNullOrEmpty(tableName))
{
throw new NullReferenceException("表名不能为空;");
}
TableName = tableName;
}

public void AddQueryParam(string name, object paramValue)
{
sqlWhere += " and " + name + "=@" + name;
sqlParaList.Add(new SqlParameter(name, paramValue));
}
/// <summary>
/// 同一列值多值
/// </summary>
/// <param name="columnName"></param>
/// <param name="key"></param>
/// <param name="keyValue"></param>
public void AddInParams(string columnName, List<string> listParams)
{
sqlWhere += " and " + columnName + "  in (";
foreach (string item in listParams)
{
sqlWhere += item + ',';
}

if (sqlWhere.Length > 0)
{
sqlWhere = sqlWhere.Remove(sqlWhere.LastIndexOf(','), 1);
}
sqlWhere += " )    ";
}
public void AddLikeQueryParam(string name, object paramValue)
{
sqlWhere += " and " + name + " like '%@" + name + "%'  ";
sqlParaList.Add(new SqlParameter(name, paramValue));
}
public void AddLetterThanParm(string name, object paramValue)
{
sqlWhere += " and " + name + "<@" + name;
sqlParaList.Add(new SqlParameter(name, paramValue));
}
public void AddGreaterThanParm(string name, object paramValue)
{
sqlWhere += " and " + name + ">@" + name;
sqlParaList.Add(new SqlParameter(name, paramValue));
}
public void AddNoEqualParam(string name, object paramValue)
{
sqlWhere += name + "<>@" + name + " and ";
sqlParaList.Add(new SqlParameter(name, paramValue));
}
public void AddBetweenQueryParam(string starttime, string endtime, object paramValue1, object paramValue2)
{
sqlWhere += " and " + starttime + " < @" + starttime;
sqlWhere += " and " + endtime + "< @" + endtime;
sqlParaList.Add(new SqlParameter(starttime, paramValue1));
sqlParaList.Add(new SqlParameter(endtime, paramValue2));
}
/// <summary>
/// Or条件查询
/// </summary>
string sqlOrWhere = string.Empty;
public void AddlikeOrParam(string name, object paramValue)
{
//sqlOrWhere += name + " like @" + name + " or ";
//sqlParaList.Add(new SqlParameter(name, " '%" + paramValue + "%' "));

sqlOrWhere += name + " like '%" + paramValue + "%' or ";
sqlParaList.Add(new SqlParameter(name, " '%" + paramValue + "%' "));
}
/// <summary>
///  分页获取数据列表
/// </summary>
/// <param name="columns">需要查询的列明数组</param>
/// <param name="page">当前页</param>
/// <param name="pageSize">页码</param>
/// <param name="sortIndex">排序索引</param>
/// <param name="sortDirction">排序升降</param>
/// <returns></returns>
public DataTable GetListByPage(string[] columns, int page, int pageSize, int sortIndex, string sortDirction, out int total)
{
StringBuilder strSql = new StringBuilder();
strSql.Append("SELECT ");
if (columns == null || columns.Length == 0)
strSql.Append(" * ");
else
{
for (int i = 0; i < columns.Length; i++)
{
strSql.Append(columns[i] + ",");
}
strSql.Remove(strSql.Length - 1, 1);
}
strSql.Append(" FROM ( ");
strSql.Append(" SELECT ROW_NUMBER() OVER (");

if (sortIndex >= 0 && sortIndex < columns.Length - 1)
{
strSql.Append(" order by T." + columns[sortIndex]);
if (sortDirction != null && (sortDirction == "asc" || sortDirction == "desc"))
{
strSql.Append("  " + sortDirction);
}
}

strSql.Append(")AS Row, T.*  from " + TableName + " T ");
if (sqlParaList != null && sqlParaList.Count > 0)
{
strSql.Append(" where 1=1");
if (!string.IsNullOrEmpty(sqlWhere))
{
strSql.Append(sqlWhere.TrimEnd(','));
}
if (!string.IsNullOrEmpty(sqlOrWhere))
{
strSql.Append(" and ( " + sqlOrWhere.Substring(0, sqlOrWhere.Length - 3) + " )");
}
}
strSql.Append(" ) TT");
strSql.AppendFormat(" WHERE TT.Row between {0} and {1}", (pageSize * (page - 1) + 1), pageSize * page);
//获取列表总行数
total = GetListCount(pageSize);
return SqlHelper.ExecuteDataTable(SqlHelper.SHOP_CONN_STR, CommandType.Text, strSql.ToString(), sqlParaList.ToArray());
}
/// <summary>
/// 获取列表总行数
/// </summary>
/// <returns></returns>
public int GetListCount(int pageSize)
{

StringBuilder strSql = new StringBuilder("select count(1)" + " from " + TableName);
if (sqlParaList != null && sqlParaList.Count > 0)
{
strSql.Append(" where 1=1");
if (!string.IsNullOrEmpty(sqlWhere))
{
strSql.Append(sqlWhere.TrimEnd(','));
}
if (!string.IsNullOrEmpty(sqlOrWhere))
{
strSql.Append(" and (" + sqlOrWhere.Substring(0, sqlOrWhere.Length - 3) + ")");
}
}
object obj = SqlHelper.ExecuteScalar(SqlHelper.SHOP_CONN_STR, CommandType.Text, strSql.ToString(), sqlParaList.ToArray());
int RowsCount = 0;
if (obj != null)
{
return RowsCount = (int)obj;
}
else
{
return 0;
}
//int total = 0;
// //if (RowsCount % pageSize == 0)
// //{
// //    total = RowsCount / pageSize;
// //}
// //else
// //{
// //    total = RowsCount / pageSize + 1;
// //}
// return total;
}

拼接json的方法

public static string TableToJson(DataTable table,int total)
{
if (table == null)
return "";
StringBuilder sb = new StringBuilder();
sb.Append("{");
sb.Append("\"total\":" + total + ",");
sb.Append("\"rows\":[");
foreach (DataRow row in table.Rows)
{
sb.Append("{");
foreach (DataColumn col in table.Columns)
{
sb.Append("\"" + col.ColumnName + "\":\"" + row[col.ColumnName] + "\",");
}
sb.Remove(sb.Length - 1, 1);
sb.Append("},");
}
sb.Remove(sb.Length - 1, 1);
sb.Append("]");
sb.Append("}");
return sb.ToString();
}