由于javascript，下拉列表选择的值不保存所选值 [英] Dropdownlist selected value not saving the selected value because of javascript
问题描述
如何使用dropdownlist项将值插入数据库，我想要的是选择Item然后当我按下提交按钮时，数值将使用asp.net vb.net代码保存到sql server数据库，问题是，它总是在sqlserver数据库中保存0值，即使我选择1,2,3或4，问题是javascript，如果我删除javascript它可以选择我想要的值并且没有问题，但我需要如果它已经被选中，它将禁用该值，以避免重复数据库，有人可以帮助我弄清楚javascript，如果我尝试按下保存按钮，你可以看到下拉列表返回到其默认值0然后重置，而不是保存我从下拉列表中选择的值，谢谢....
我尝试过：
<％@ Page Language =VBAutoEventWireup =falseCodeFile =Default.aspx.vb
Inherits =_ DefaultDebug = true％>
&l t;！DOCTYPE html>
< html xmlns =http://www.w3.org/1999/xhtml>
< head runat =server>
< title>< / title>
< / head>
< body>
< form id =form1runat =server>
How can I Insert value to database using dropdownlist item, What I want is to select Item then when I press submit button, the numeric Value will save to sql server database using asp.net vb.net code, the problem is ,it always save 0 value in sqlserver database, even if I selected 1, 2 , 3, or 4 , the problem is the javascript, if I remove the javascript it can select the value that I want and there is no problem, but I need it to disable the value if its already selected, to avoid duplicates to the database, can someone help me to figure it out the javascript, if I try press the save button you can see that the dropdownlist is returning to its default value 0 then reset, and not saving the value that I selected from the dropdownlist thanks....
What I have tried:
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb"
Inherits="_Default" Debug="true"%>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
< asp：DropDownList ID =frstrunat =serverAutoPostBack =true>
< asp：ListItem value = 0>选择
< asp：ListItem value =1> 1
< asp：ListItem value =2> 2
< asp：ListItem value =3> 3
< asp：ListItem value =4> 4
< asp：DropDownList ID =secndrunat =server>
< asp：ListItem value =0>选择
< asp：ListItem value =1> 1
< asp：ListItem value =2> 2
< asp：ListItem value =3> 3
< asp：ListItem value =4> 4
< asp：Button ID =btnSaverunat =serverText =Save
OnClick =btnSave_Click/>
< asp：Label ID =lblmsgrunat =server>
<asp:DropDownList ID = "frst" runat="server" AutoPostBack="true">
<asp:ListItem value="0">Select
<asp:ListItem value="1">1
<asp:ListItem value="2">2
<asp:ListItem value="3">3
<asp:ListItem value="4">4
<asp:DropDownList ID = "secnd" runat="server">
<asp:ListItem value="0">Select
<asp:ListItem value="1">1
<asp:ListItem value="2">2
<asp:ListItem value="3">3
<asp:ListItem value="4">4
<asp:Button ID="btnSave" runat="server" Text="Save"
OnClick="btnSave_Click" />
<asp:Label ID="lblmsg" runat="server">
< script type =text / javascript>
var ids = ['frst'，'secnd'];
NodeList.prototype.forEach = HTMLCollection.prototype.forEach =
Array.prototype.forEach;
var selected = [];
ids = makeid（ids）;
var opts = find（ids）;
updateS（opts）;
massdisabler（opts）;
assignFunc（ids，disabler）;
函数assignFunc（i，func）{//完成
var x;
for（x = 0; x < i.length; ++ x）{
i [x] .onchange = function（）{
func（this）;
};
}
}
函数disabler（i）{
console.log（已选择）;
updateS（opts）;
massdisabler（opts）;
}
函数makeid（i）{//完成
var o = [];
i.forEach（function（v）{
o.push（document.getElementById（v））
}）;
返回o;
}
函数查找（ids）{//完成
var o = {};
for（var i = 0;我< ids.length; ++ i）{
o [i] = {};
ids [i] .children.forEach（function（v，n）{
o [i] [n] = v;
}）;
}
返回o;
}
function massdisabler（op）{//完成
var y = Object.keys（op ）。长度;
for（var x = 0; x< y; x ++）{
var t = 0，
l = Object .keys（opts [x]）。length;
for（var v = 0; v< l; v ++）{
t = op [x] [v] ;
if（selected.some（function（k）{
if（t.value == k）{
返回true;
}
}））{
t.setAttribute（disabled，disabled）;
}其他{
t.removeAttribute（禁用）;
}
}
}
}
函数更新（op）{//完成
var s = []，
y = Object.keys（op）.length;
for（var x = 0; x< Ÿ; x ++）{
var t = 0，
l = Object.keys（opts [x]）。length;
for（var v = 0; v< l; v ++）{
t = op [x] [v];
var yn = s.some（function（k）{
if（t.value == k）{
return true;
如果（t.selected&&（！yn））s.push（t.value）;
}
}
选择= s;
}
< / script>
< / form>
< / body>
< / html>
受保护的子btnSave_Click（发件人为对象，e为EventArgs）
Dim cs As String = ConfigurationManager.ConnectionStrings（constr）。ConnectionString
Dim cn As SqlConnection = New SqlConnection（cs）
Dim cmd As SqlCommand = New SqlCommand（）
cmd.Connection = cn
cmd.CommandType = CommandType.Text
cmd.CommandText =插入名称值（@ FirstValue，@ SecondValue ）
cmd.Parameters.Clear（）
cmd.Parameters.AddWithValue（@ FirstValue，frst.SelectedItem.Value）
cmd.Parameters.AddWithValue（@ SecondValue，secnd.SelectedItem.Value）
如果cn.State = ConnectionState.Closed那么
cn.Open（）
结束如果
cmd.ExecuteNonQuery（）
cn.Close（）
lblmsg.Text =数据输入成功！ !!
End Sub
<script type="text/javascript">
var ids = ['frst', 'secnd'];
NodeList.prototype.forEach = HTMLCollection.prototype.forEach =
Array.prototype.forEach;
var selected = [];
ids = makeid(ids);
var opts = find(ids);
updateS(opts);
massdisabler(opts);
assignFunc(ids, disabler);
function assignFunc(i, func) { //done
var x;
for (x = 0; x < i.length; ++x) {
i[x].onchange = function () {
func(this);
};
}
}
function disabler(i) {
console.log(selected);
updateS(opts);
massdisabler(opts);
}
function makeid(i) { //done
var o = [];
i.forEach(function (v) {
o.push(document.getElementById(v))
});
return o;
}
function find(ids) { //done
var o = {};
for (var i = 0; i < ids.length; ++i) {
o[i] = {};
ids[i].children.forEach(function (v, n) {
o[i][n] = v;
});
}
return o;
}
function massdisabler(op) { //done
var y = Object.keys(op).length;
for (var x = 0; x < y; x++) {
var t = 0,
l = Object.keys(opts[x]).length;
for (var v = 0; v < l; v++) {
t = op[x][v];
if (selected.some(function (k) {
if (t.value == k) {
return true;
}
})) {
t.setAttribute("disabled", "disabled");
} else {
t.removeAttribute("disabled");
}
}
}
}
function updateS(op) { //done
var s = [],
y = Object.keys(op).length;
for (var x = 0; x < y; x++) {
var t = 0,
l = Object.keys(opts[x]).length;
for (var v = 0; v < l; v++) {
t = op[x][v];
var yn = s.some(function (k) {
if (t.value == k) {
return true;
}
});
if (t.selected && (!yn)) s.push(t.value);
}
}
selected = s;
}
</script>
</form>
</body>
</html>
Protected Sub btnSave_Click(sender As Object, e As EventArgs)
Dim cs As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Dim cn As SqlConnection = New SqlConnection(cs)
Dim cmd As SqlCommand = New SqlCommand()
cmd.Connection = cn
cmd.CommandType = CommandType.Text
cmd.CommandText = "insert into Names values(@FirstValue,@SecondValue)"
cmd.Parameters.Clear()
cmd.Parameters.AddWithValue("@FirstValue", frst.SelectedItem.Value)
cmd.Parameters.AddWithValue("@SecondValue", secnd.SelectedItem.Value)
If cn.State = ConnectionState.Closed Then
cn.Open()
End If
cmd.ExecuteNonQuery()
cn.Close()
lblmsg.Text = "Data entered successfully!!!"
End Sub
推荐答案
我没有仔细查看你的javascript代码，但可以建议你可以说的方法或解决方法。这绝对不是完美的方法，但你可以使用它作为解决方法，直到人们提出更好的建议。
添加一个asp.net隐藏字段和将值设置为0.将dropdownlist的Postback peoperty设置为true。然后在下拉列表的选定索引更改事件上将值设置为相应的选定值。在进行插入时，您可以从此隐藏字段中获取所选值。
希望，它有帮助：）
I haven't looked at your javascript code closely but can suggest a way or workaround you can say. It's definitely not the perfect way to do this, but you can use it as a workaround till people come up with better suggestions.
Add an asp.net hidden field and set the value to 0. Set the Postback peoperty of dropdownlist to true. Then on selected index changed event of dropdownlist set the value to respective selected value. While doing insert you can get the selected value from this hidden field.
Hope, it helps :)
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