如何检查是否为空?

时间:2012-11-20 10:26:39

标签: asp.net null isnull isnullorempty

我在aspx文件中有以下代码。我想在查询返回0行或null时显示一条消息。如何检查这个是正确的,因为我的示例没有捕获空值。

        protected void search_Click(object sender, EventArgs e)
    {
        string searchItem;
        searchItem = "Select * FROM test WHERE (name like '%"+searchTxt.Text.ToString()+"%')";
        SqlDataSource.SelectCommand = searchItem;    
        if (SqlDataSource.SelectCommand == null)
            hiddenMsg.Visible = true;
        else
            SqlDataSource.SelectCommand = searchItem;

    }

1 个答案:

答案 0 :(得分:1)

int count = Convert.ToInt32(cmd.ExecuteScalar());
        if (count == 0)
        {
             display your message that no rows returned
        }
        else {
           display rows returned
       }

享受