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();
        }