[英]create a c# listBox in run time to select multiple choices (that comes from database)
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这是一个简单的应用程序,管理员可以准备问卷并准备简单的调查并与我们网站上注册的任何人共享。
最终用户完成调查后,网站管理员(或授权的任何人)都可以以任何形式(例如图形或文本)分析调查结果和其他反馈。
-但是里面有些东西坏了-
当您添加问题时,您可以选择问题的类型,因此我开设了此类
public enum QuestionTypes
{
SingleLineTextBox, // will render a textbox
MultiLineTextBox, // will render a text area
YesOrNo, //will render a checkbox
SingleSelect, //will render a dropdownlist
MultiSelect //will render a listbox
}
并将其保存为字符串,但是以不同的方式在运行时呈现(文本框,SingleLineTextBox,YesOrNo可以正常工作,但是MultiSelect和YesOrNo不能工作)
此应用程序使用实体框架-有一节添加问题。 看起来像这样:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
ddlTypes.Items.Add(QuestionTypes.SingleLineTextBox.ToString());
ddlTypes.Items.Add(QuestionTypes.MultiLineTextBox.ToString());
ddlTypes.Items.Add(QuestionTypes.SingleSelect.ToString());
ddlTypes.Items.Add(QuestionTypes.MultiSelect.ToString());
ddlTypes.Items.Add(QuestionTypes.YesOrNo.ToString());
}
}
protected void btnSubmit_Click(object sender, EventArgs e)
{
if (Page.IsValid)
{
SurveyAppConString context = new SurveyAppConString();
Question quest = new Question();
quest.Text = txtTitle.Text.Trim();
quest.QuestionType = ddlTypes.SelectedItem.Text;
quest.Options = txtValues.Text.Trim();
context.AddToQuestions(quest);
context.SaveChanges();
}
之后,您可以将任何问题分配给调查,然后会有一个页面显示所有调查。 它在那儿坏了。 我想在运行时创建一个复选框,并将其值作为字符串保存在数据库中,并使用列表框进行相同操作
这是示例代码(适用于文本框和下拉列表)
private void PopulateSurvey()
{
btnSubmit.Enabled = true;
List<Question> questions = (from p in context.Questions
join q in context.SurveyQuestions on p.ID equals q.QuestionID
where q.SurveyID == surveyid
select p).ToList();
Table tbl = new Table();
tbl.Width = Unit.Percentage(100);
TableRow tr;
TableCell tc;
TextBox txt;
CheckBox cbk;
DropDownList ddl;
foreach (Question q in questions)
{
tr = new TableRow();
tc = new TableCell();
tc.Width = Unit.Percentage(25);
tc.Text = q.Text;
tc.Attributes.Add("id", q.ID.ToString());
tr.Cells.Add(tc);
tc = new TableCell();
if (q.QuestionType.ToLower() == "singlelinetextbox")
{
txt = new TextBox();
txt.ID = "txt_" + q.ID;
txt.Width = Unit.Percentage(40);
tc.Controls.Add(txt);
}
if (q.QuestionType.ToLower() == "multilinetextbox")
{
txt = new TextBox();
txt.ID = "txt_" + q.ID;
txt.TextMode = TextBoxMode.MultiLine;
txt.Width = Unit.Percentage(40);
tc.Controls.Add(txt);
}
if (q.QuestionType.ToLower() == "singleselect")
{
ddl = new DropDownList();
ddl.ID = "ddl_" + q.ID;
ddl.Width = Unit.Percentage(41);
if (!string.IsNullOrEmpty(q.Options))
{
string[] values = q.Options.Split(',');
foreach (string v in values)
ddl.Items.Add(v.Trim());
}
tc.Controls.Add(ddl);
}
tc.Width = Unit.Percentage(80);
tr.Cells.Add(tc);
tbl.Rows.Add(tr);
}
pnlSurvey.Controls.Add(tbl);
}
您可以在此处快速检查完整的代码,这是一个数据库图:
注意-我在复选框区域工作并添加了类似的代码
我这样做的代码
if (q.QuestionType.ToLower() == "yesorno")
{
lblyes = new Label();
lblyes.Text = "yes";
tc.Controls.Add(lblyes);
cbk = new CheckBox();
cbk.ID = "cbk_" + q.ID;
//cbk.value = "true";
cbk.Width=Unit.Percentage(41);
tc.Controls.Add(cbk);
}
// On Postback|Save
sres.Response = (ctrc as CheckBox).Checked ? "yes" : "no";
它工作正常(一个复选框)
创建两个复选框(最好创建一个单选按钮)
if (q.QuestionType.ToLower() == "yesorno")//this is the name you create it when add anew question type
{
lblyes = new Label();
lblyes.Text = "yes";
tc.Controls.Add(lblyes);
rbk = new RadioButton();
rbk.ID = "rbk_" + q.ID;
rbk.GroupName = "rbyesno";
rbk.Width = Unit.Percentage(41);
tc.Controls.Add(rbk);
//add another chexbox and label
lblno = new Label();
lblno.Text = "no";
tc.Controls.Add(lblno);
rbk = new RadioButton();
rbk.ID = "cbk_1" + q.ID;
rbk.GroupName = "rbyesno";
rbk.Width = Unit.Percentage(41);
tc.Controls.Add(rbk);
}
// On Postback|Save
else if (ctrc is RadioButton)
{
//sres.Response = (ctrc as CheckBox).Checked.ToString();
sres.Response = (ctrc as RadioButton).Checked ? "no" : "yes";
}
---现在我只需要创建一个列表即可从表单中选择多个选项并将其作为字符串发送到数据库
---当我尝试添加列表框时,请colud添加一个多重选择查询类型以进行查询
这是代码的摘要
if (q.QuestionType.ToLower() == "MultiSelect")
{
lstmulti = new ListBox();
lstmulti.ID = "lst_" + q.ID;
lstmulti.Width = Unit.Percentage(41);
//lstmulti.Items.Add("on");
//lstmulti.Items.Add("sgsd");
//lstmulti.Items.Add("thre");
if (!string.IsNullOrEmpty(q.Options))
{
string[] values = q.Options.Split(',');
foreach (string v in values)
lstmulti.Items.Add(v.Trim());
}
tc.Controls.Add(lstmulti);
}
在保存其他情况下(ctrc是ListBox){//sres.Response =(ctrc作为ListBox).SelectionMode.ToString(); sres.Response =(ctrc作为ListBox).SelectedValue;
}
它也没有呈现为alistbox
//在运行时创建列表,如果(q.QuestionType.ToLower()==“ MultiSelect”){ListBox lstmulti = new ListBox(); lstmulti.ID =“ lst_” + q.ID; lstmulti.Width = Unit.Percentage(41); lstmulti.Height = Unit.Percentage(100);
lstmulti.SelectionMode = ListSelectionMode.Multiple;
//to select multible choices and send to database
if (lstmulti.SelectionMode == ListSelectionMode.Multiple)
{
var selected = new List<string>();
for (int i = 0; i < lstmulti.Items.Count; i++)
{
if (lstmulti.Items[i].Selected)
selected.Add(lstmulti.Items[i].Text);
string selectedItem = lstmulti.Items[i].Text;
//insert command
///it should send the result to databse where the table name is Survey_Response and column is Response
//SurveyAppConString db=new SurveyAppConString();
// //db.Survey_Response.Include(m => m.Response) = string.Join(",", selected);
}
}
if (!string.IsNullOrEmpty(q.Options))
{
string[] values = q.Options.Split(',');
foreach (string v in values)
lstmulti.Items.Add(v.Trim());
}
tc.Controls.Add(lstmulti);
}
//保存后
else if (ctrc is ListBox)
{
//sres.Response = (ctrc as ListBox).SelectionMode.ToString();
sres.Response = (ctrc as ListBox).Items.ToString();
}
notes ::我正在将asp.net Webform与实体框架一起使用
您可以轻松地遵循该示例,并添加具有“ true”值的复选框控件。 问题是未选中的复选框不会作为表单值传递,因此如果表单名称不存在于表单发布中,则可以将其设置为默认的“ false”,也可以在复选框字段之后设置隐藏的默认值并使用第一个通过的值
MVC中的模型绑定将为您做到这一点https://stackoverflow.com/a/14731571/60669
由于脚本只是查看服务器控件,因此它甚至更简单
if (q.QuestionType.ToLower() == "yesorno")
{
var cb = new Checkbox();
cb.Id = "cb_" + q.id;
cb.Value = "true;
// add to table cell
}
// On Postback|Save
if (ctrl is Checkbox)
{
sres.Result = (ctrl as Checkbox).Checked ? "true" : "false"
}
对于列表框,您必须将SelectionMode设置为multiple并将大小设置为可渲染。 在回发时,如果SelectionMode为多个,则需要循环这些项目并连接结果。
if (myListBox.SelectionMode == SelectionMode.Multiple)
{
var selected = new List<string>();
foreach (var item in myListBox.Items)
if (item.Selected)
selected.Add(item.Text);
response = string.Join(",", selected);
}
由于语法错误,列表框未呈现,通常工作的代码在这里
//create list in run time
if (q.QuestionType == "MultiSelect")
{
lstmulti = new ListBox();
lstmulti.ID = "lst_" + q.ID;
lstmulti.Width = Unit.Percentage(41);
lstmulti.Height = Unit.Percentage(100);
lstmulti.SelectionMode = ListSelectionMode.Multiple;
//to retrive the option values
if (!string.IsNullOrEmpty(q.Options))
{
string[] values = q.Options.Split(',');
foreach (string v in values)
lstmulti.Items.Add(v.Trim());
}
tc.Controls.Add(lstmulti);
}
tc.Width = Unit.Percentage(80);
tr.Cells.Add(tc);
tbl.Rows.Add(tr);
}
pnlSurvey.Controls.Add(tbl);
}
在保存
else if (ctrc is ListBox)
{
var selected = new List<string>();
for (int i = 0; i < lstmulti.Items.Count; i++)
{
if (lstmulti.Items[i].Selected)
selected.Add(lstmulti.Items[i].Text);
string selectedItem = lstmulti.Items[i].Text;
sres.Response = string.Join(",", selected) ;
}
}
}
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