private void pageload()
{
strqry = "Select top 5 * From T_Product order by id desc";
OleDbDataReader dr;
dr = DBFun.dataReader(strqry);
while(dr.Read()) //出错行:未将对象引用设置到对象的实例
{ //标题
texts += dr["ProductName"].ToString() + "|";
//链接 links += "ShowImageNews.aspx?id="+id+"|"; //这里根据你的链接情况修改
links = "";
//图片地址
pics += "uploadpic/" + dr["ProductPic"].ToString() + "|";
}
}
异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。以下是方法:
public static OleDbDataReader dataReader(string sqlstr)
{
OleDbDataReader dr = null;
try
{
openConnection();
comm.CommandText = sqlstr;
comm.CommandType = CommandType.Text;
dr = comm.ExecuteReader(CommandBehavior.CloseConnection);
}
catch
{
try
{
dr.Close();
closeConnection();
}
catch
{
}
}
return dr;
}
{
strqry = "Select top 5 * From T_Product order by id desc";
OleDbDataReader dr;
dr = DBFun.dataReader(strqry);
while(dr.Read()) //出错行:未将对象引用设置到对象的实例
{ //标题
texts += dr["ProductName"].ToString() + "|";
//链接 links += "ShowImageNews.aspx?id="+id+"|"; //这里根据你的链接情况修改
links = "";
//图片地址
pics += "uploadpic/" + dr["ProductPic"].ToString() + "|";
}
}
异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。以下是方法:
public static OleDbDataReader dataReader(string sqlstr)
{
OleDbDataReader dr = null;
try
{
openConnection();
comm.CommandText = sqlstr;
comm.CommandType = CommandType.Text;
dr = comm.ExecuteReader(CommandBehavior.CloseConnection);
}
catch
{
try
{
dr.Close();
closeConnection();
}
catch
{
}
}
return dr;
}
if(dr!=null)
{while(dr.Read())
{ //标题
...
}
}
你把这个里面的try catch都注释掉,看看什么错误。
你看一下你的方法 public static OleDbDataReader dataReader(string sqlstr)
你把colse放在catch里面,那就是说只有出错的时候才会执行
{
OleDbDataReader dr = null;
try
{
openConnection();
comm.CommandText = sqlstr;
comm.CommandType = CommandType.Text;
dr = comm.ExecuteReader(CommandBehavior.CloseConnection);
}
catch
{
try
{
dr.Close(); //读取完之后才关掉哦.
closeConnection();
}
catch
{
}
}
return dr;
}
/// <summary>
/// 执行查询语句,返回OleDbDataReader
/// </summary>
/// <param name="strSQL">查询语句</param>
/// <returns>OleDbDataReader</returns>
public static OleDbDataReader ExecuteReader(string strSQL)
{
OleDbConnection connection = new OleDbConnection(connectionString);
OleDbCommand cmd = new OleDbCommand(strSQL, connection);
try
{
connection.Open();
OleDbDataReader myReader = cmd.ExecuteReader();
return myReader;
}
catch (System.Data.OleDb.OleDbException e)
{
throw new Exception(e.Message);
} }
var files = 'uploadpic/201004\20100423.JPG|uploadpic/201004\201004165.JPG|uploadpic/201004\201004395.JPG|uploadpic/201004\201004597.JPG|uploadpic/201004\201004300.JPG|';
图片路径有问题,这个怎么改