如何取得list控件中DataTextField,DataValueField的值。 - ASP.NET技术论坛

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如何取得list控件中DataTextField,DataValueField的值。

我有一个表，有三个字段。
NewsKindID NewsKindName Order
1 今日报道 0
2 每周快讯 1
3 国内新闻 2
4 国际新闻 3

如下图。我将list控件中DataTextField,DataValueField属性的值分别设为NewsKindID和NewsKindName。

我现在想通过点击list控件旁边的“向上箭头”和“向下箭头”键来改变list中值的排序。

如，当list的SelectedItem值为第三项“国内新闻”时，单击“向上箭头”，将会使其Order值由原先的"2"变成"1"，
同时“每周快讯”项的Order值由"1"变成"2"，其“向上箭头”的代码该如何写？

[此贴子已经被作者于2006-2-21 23:49:37编辑过]

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第 2 楼

得分:0

string id=newslist.SelectedItem.Value.TOString();
向上：sql="update 表 set Order=Order+1 where NewsKindID="+id;
执行
sql="update 表 set Order=Order-1 where Order=(select Order from 表 where id="+id+") and NewsKindID<>"+id;
执行
向下：sql="update 表 set Order=Order-1 where Order="+newslist.SelectedItem.Value;
执行
sql="update 表 set Order=Order+1 where Order=(select Order from 表 where id="+id+") and NewsKindID<>"+id;
执行

要注意第一个和最后一个的移动限制

">东搞一下西搞一下

第 3 楼

得分:0

TO: islet
依你的方法，问题已解决，用SELECT嵌套，的确省去了很多中间过程，谢谢。

我的完整代码如下：

private void upBtn_Click(object sender, System.Web.UI.ImageClickEventArgs e)
{
if(NewsKindList.SelectedIndex > 0)
{
int nSelectedIndex = NewsKindList.SelectedIndex;
String id = NewsKindList.SelectedItem.Value.ToString();
SqlConnection myConnection = new SqlConnection(GlobalDB.DataBaseDB.ConnectionString);
String cmdText = "UPDATE NewsKinds SET KindOrder = KindOrder - 1 WHERE NewsKindID = " + id;
SqlCommand myCommand = new SqlCommand(cmdText,myConnection);
myConnection.Open();
myCommand.ExecuteNonQuery();
cmdText = "UPDATE NewsKinds SET KindOrder = KindOrder + 1 WHERE KindOrder = (SELECT KindOrder FROM NewsKinds WHERE NewsKindID = " + id + ") AND NewsKindID <> " + id;
myCommand = new SqlCommand(cmdText,myConnection);
myCommand.ExecuteNonQuery();
myConnection.Close();
BindNewsKindData();
NewsKindList.SelectedIndex = Math.Max(0,(nSelectedIndex - 1));
}
}

private void downBtn_Click(object sender, System.Web.UI.ImageClickEventArgs e)
{
if(NewsKindList.SelectedIndex < (NewsKindList.Items.Count - 1))
{
int nSelectedIndex = NewsKindList.SelectedIndex;
String id = NewsKindList.SelectedItem.Value.ToString();
SqlConnection myConnection = new SqlConnection(GlobalDB.DataBaseDB.ConnectionString);
String cmdText = "UPDATE NewsKinds SET KindOrder = KindOrder + 1 Where NewsKindID = " + id;
SqlCommand myCommand = new SqlCommand(cmdText,myConnection);
myConnection.Open();
myCommand.ExecuteNonQuery();
cmdText = "UPDATE NewsKinds SET KindOrder = KindOrder -1 WHERE KindOrder = (SELECT KindOrder FROM NewsKinds WHERE NewsKindID = " + id + ") AND NewsKindID <> " + id;
myCommand = new SqlCommand(cmdText,myConnection);
myCommand.ExecuteNonQuery();
myConnection.Close();
BindNewsKindData();
NewsKindList.SelectedIndex = Math.Min((NewsKindList.Items.Count - 1),(nSelectedIndex + 1));
}
}

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