|
#2
冰镇柠檬汁儿2010-05-27 10:23
|
我的网站运行就提示我Fill: SelectCommand.Connection 属性未初始化，怎么修改，代码如下：
app_code中的CCUtility.cs代码
namespace student1
{
using System;
using System.Collections;
using
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Configuration;
//定义PositionData类
public class PositionData
{
private string name;
private string CatID;
public PositionData(string Name, string CategoryID)
{
this.name = Name;
this.CatID = CategoryID;
}
public string Name
{
get
{
return name;
}
}
public string CategoryID
{
get
{
return CatID;
}
}
}
//定义CCUtility类
public class CCUtility
{
public const int FIELD_TYPE_Text = 0;
public const int FIELD_TYPE_Number = 1;
public const int FIELD_TYPE_Date = 2;
public const int FIELD_TYPE_Memo = 3;
protected HttpSessionState Session;
protected HttpServerUtility Server;
protected HttpRequest Request;
protected HttpResponse Response;
//转换为标准的SQL语句
public static string ToSQL(string Param, int iType)
{
if (Param == null || Param.Length == 0)
{
return "Null";
}
else
{
string str = Quote(Param);
if (iType == FIELD_TYPE_Number)
{
return str.Replace(',','.');
}
else
{
return "\'" + str + "\'";
}
}
}
//构造函数
public CCUtility(object parent)
{
DBOpen();
try
{
Session=((System.Web.UI.Page)parent).Session;
Server=((System.Web.UI.Page)parent).Server;
Request=((System.Web.UI.Page)parent).Request;
Response=((System.Web.UI.Page)parent).Response;
}
catch
{
Session=((System.Web.UI.UserControl)parent).Session;
Server=((System.Web.UI.UserControl)parent).Server;
Request=((System.Web.UI.UserControl)parent).Request;
Response=((System.Web.UI.UserControl)parent).Response;
}
}
public String GetValFromLOV(String val, String[] arr)
{
String ret = "";
if (arr.Length % 2 == 0)
{
int temp=Array.IndexOf(arr,val);
ret=temp==-1?"":arr[temp+1];}
return ret;
}
//判断数据类型是否为数值型
public bool IsNumeric(object source, string value)
{
try
{
Decimal temp=Convert.ToDecimal(value);
return true;
}
catch
{
return false;
}
}
//单引号替换为双引号
public static string Quote(string Param)
{
if (Param == null || Param.Length == 0)
{
return "";
}
else
{
return Param.Replace("'","''");
}
}
//获得DataRow对象中row中的field值
public static string GetValue(DataRow row, string field)
{
if (row[field].ToString() == null)
return "";
else
return row[field].ToString();
}
//与数据库连接方法的定义
public SqlConnection Connection;
//建立一个数据集
public DataSet FillDataSet(string sSQL)
{
DataSet ds = new DataSet();
SqlDataAdapter command = new SqlDataAdapter(sSQL, Connection);
return ds;
}
//数据集中添加或刷新行
public int FillDataSet(string sSQL,ref DataSet ds)
{
SqlDataAdapter command = new SqlDataAdapter(sSQL, Connection);
return command.Fill(ds, "Table");
}
//
public int FillDataSet(string sSQL,ref DataSet ds,int start, int count)
{
SqlDataAdapter command = new SqlDataAdapter(sSQL, Connection);
return command.Fill(ds, start, count, "Table");
}
//打开数据库连接
public void DBOpen()
{
//从Web.Config中获取连接数据库字符串
string sConnectionString = ConfigurationSettings.AppSettings["SQLConnectionString"];
//创建一个连接实例
SqlConnection Connection = new SqlConnection(sConnectionString);
Connection.Open();
}
//关闭数据库连接
public void DBClose()
{
Connection.Close();
}
public string GetParam(string ParamName)
{
string Param = Request.QueryString[ParamName];
if (Param == null)
Param = Request.Form[ParamName];
if (Param == null)
return "";
else
return Param;
}
//数据库查询，并将字符串数据结果返回
public string Dlookup(string table, string field, string sWhere)
{
string sSQL = "SELECT " + field + " FROM " + table + " WHERE " + sWhere;
SqlCommand command = new SqlCommand(sSQL, Connection);
SqlDataReader reader=command.ExecuteReader(CommandBehavior.SingleRow);
string sReturn;
if (reader.Read())
{
sReturn = reader[0].ToString();
if (sReturn == null)
sReturn = "";
}
else
{
sReturn = "";
}
reader.Close();
return sReturn;
}
//数据库查询，并返回数值型数据
public int DlookupInt(string table, string field, string sWhere)
{
string sSQL = "SELECT " + field + " FROM " + table + " WHERE " + sWhere;
SqlCommand command = new SqlCommand(sSQL, Connection);
SqlDataReader reader=command.ExecuteReader(CommandBehavior.SingleRow);
int iReturn = -1;
if (reader.Read())
{
iReturn = reader.GetInt32(0);
}
reader.Close();
return iReturn;
}
//执行语句
public void Execute(string sSQL)
{
SqlCommand cmd = new SqlCommand(sSQL, Connection);
cmd.ExecuteNonQuery();
}
//执行语句，将数据绑定到ListBox控件上
public void buildListBox(ListItemCollection Items,string sSQL, string sId, string sTitle, string CustomInitialDisplayValue,string CustomInitialSubmitValue)
{
Items.Clear();
SqlCommand command = new SqlCommand(sSQL, Connection);
SqlDataReader reader = command.ExecuteReader();
if(CustomInitialDisplayValue!=null) Items.Add(new ListItem(CustomInitialDisplayValue,CustomInitialSubmitValue));
while(reader.Read())
{
if(sId==""&&sTitle=="")
{
Items.Add(new ListItem(reader[1].ToString(),reader[0].ToString()));
}
else
{
Items.Add(new ListItem(reader[sTitle].ToString(),reader[sId].ToString()));
}
}
reader.Close();
}
public void buildListBox(ListItemCollection Items,string[] values, string CustomInitialDisplayValue,string CustomInitialSubmitValue)
{
Items.Clear();
if(CustomInitialDisplayValue!=null) Items.Add(new ListItem(CustomInitialDisplayValue,CustomInitialSubmitValue));
for(int i=0;i<values.Length;i+=2)Items.Add(new ListItem(values[i+1],values[i]));
}
public ICollection buildListBox(string sSQL, string sId, string sTitle, string CustomInitialDisplayValue,string CustomInitialSubmitValue)
{
DataRow row;
SqlDataAdapter command = new SqlDataAdapter(sSQL, Connection);
DataSet ds = new DataSet();
ds.Tables.Add("lookup");
DataColumn column = new DataColumn();
column.DataType = System.Type.GetType("System.String");
column.ColumnName = sId;
ds.Tables[0].Columns.Add(column);
column = new DataColumn();
column.DataType = System.Type.GetType("System.String");
column.ColumnName = sTitle;
ds.Tables[0].Columns.Add(column);
if (CustomInitialDisplayValue!=null)
{
row = ds.Tables[0].NewRow();
row[0] = CustomInitialSubmitValue;
row[1] = CustomInitialDisplayValue;
ds.Tables[0].Rows.Add(row);}
command.Fill(ds, "lookup");
return new DataView(ds.Tables[0]);
}
public static string getCheckBoxValue(string sVal, string CheckedValue, string UnCheckedValue, int iType)
{
if (sVal.Length == 0)
{
return ToSQL(UnCheckedValue, iType);
}
else
{
return ToSQL(CheckedValue, iType);
}
}
//安全性验证
public bool CheckSecurity(int iLevel)
{
if (Session["UserID"] == null || Session["UserID"].ToString().Length == 0)
{
return false;
}
else
{
if (Int16.Parse(Session["UserRights"].ToString()) < iLevel)
{
return false;
}
else return true;
}
}
}
}
出现错误代码的地方：
Grid_sSQL = Grid_sSQL + sWhere + sOrder;
SqlDataAdapter command = new SqlDataAdapter(Grid_sSQL, Utility.Connection);
DataSet ds = new DataSet();
command.Fill(ds, 0, Grid_PAGENUM, "Grid");//提示错误处。
DataView Source;
Source = new DataView(ds.Tables[0]);
第二个错误出现在关闭数据库函数中，提示：未将对象引用设置到对象的实例。
错误代码是app_code中的CCUtility.cs代码中关闭代码的那一段：
public void DBClose()
{
Connection.Close();//提示错误处。
}
我是新手，希望大家帮忙，给我说的仔细点。