判断“数据集为空的”的问题
从数据库里查不到数据时为什么会报“if(ds.Tables["Expert_Expert"].Rows.Count>0)”有错,显示“未将对象引用到实例”呢?
谢谢!
string strconn=ConfigurationSettings.AppSettings["dsn"];
SqlConnection cn=new SqlConnection(strconn);
SqlDataAdapter da=new SqlDataAdapter("select * from Expert_Expert where Name='"+ExpertName+"' ",cn);
DataSet ds=new DataSet();
da.Fill(ds);
DataGrid.DataSource=ds;
DataGrid.DataBind();
cn.Close();
if(ds.Tables["Expert_Expert"].Rows.Count>0)
this.Label_ChooseExpertNo.Visible=false;
else
this.Label_ChooseExpertNo.Visible=true;
问题点数:10、回复次数:2Top
1 楼perilla(紫苏)回复于 2006-03-03 21:06:52 得分 0
试一试:
if(ds.Tables[0]!=null)Top
2 楼ljhkim6()回复于 2006-03-03 21:11:28 得分 0
string strconn=ConfigurationSettings.AppSettings["dsn"];
SqlConnection cn=new SqlConnection(strconn);
SqlDataAdapter da=new SqlDataAdapter("select * from Expert_Expert where Name='"+ExpertName+"' ",cn);
DataSet ds=new DataSet();
da.Fill(ds);
if(ds.Tables["Expert_Expert"].Rows.Count>0)
{
DataGrid.DataSource=ds;
DataGrid.DataBind();
this.Label_ChooseExpertNo.Visible=false;
}
else
{
this.Label_ChooseExpertNo.Visible=true;
}
cn.Close();
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