C#下拉列表绑定默认值

本文介绍了C#下拉列表绑定默认值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

当dropdownlist具有从数据库数据集中获取的datatext字段和datavalue字段时，如何在零索引位置添加默认值选择一个".

how can i add default value "select one" at zero index position when dropdownlist is having datatext field and datavalue field which is obtained from database througt dataset.

推荐答案

protected void Page_Load(object sender, EventArgs e)
 {


     if (!IsPostBack)
     {
         //  you must set the connection first.
        // e.g c.setcon(); // here this is method for setting a connection
         DataSet ds = new DataSet();
        SqlDataAdapter myda = new SqlDataAdapter("Select field1  FROM Table", connection object);
        myda.Fill(ds);
        DropDown1.DataSource = ds;
        DropDown1.DataValueField = "field1";
        DropDown1.DataBind();
        DropDown1.Items.Insert(0, new ListItem("Select One", "0"));

     }

 }

希望这能对您有所帮助，否则请贴出来.

hope this will help you, if not then dear please post it.

select 0, "select one"
UNION
select colA, colB from tableA

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