[英]create a c# listBox in run time to select multiple choices (that comes from database)
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這是一個簡單的應用程序,管理員可以准備問卷並准備簡單的調查並與我們網站上注冊的任何人共享。
最終用戶完成調查后,網站管理員(或授權的任何人)都可以以任何形式(例如圖形或文本)分析調查結果和其他反饋。
-但是里面有些東西壞了-
當您添加問題時,您可以選擇問題的類型,因此我開設了此類
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
}
並將其保存為字符串,但是以不同的方式在運行時呈現(文本框,SingleLineTextBox,YesOrNo可以正常工作,但是MultiSelect和YesOrNo不能工作)
此應用程序使用實體框架-有一節添加問題。 看起來像這樣:
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,您可以將任何問題分配給調查,然后會有一個頁面顯示所有調查。 它在那兒壞了。 我想在運行時創建一個復選框,並將其值作為字符串保存在數據庫中,並使用列表框進行相同操作
這是示例代碼(適用於文本框和下拉列表)
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);
}
您可以在此處快速檢查完整的代碼,這是一個數據庫圖:
注意-我在復選框區域工作並添加了類似的代碼
我這樣做的代碼
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(一個復選框)
創建兩個復選框(最好創建一個單選按鈕)
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";
}
---現在我只需要創建一個列表即可從表單中選擇多個選項並將其作為字符串發送到數據庫
---當我嘗試添加列表框時,請colud添加一個多重選擇查詢類型以進行查詢
這是代碼的摘要
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);
}
在保存其他情況下(ctrc是ListBox){//sres.Response =(ctrc作為ListBox).SelectionMode.ToString(); sres.Response =(ctrc作為ListBox).SelectedValue;
}
它也沒有呈現為alistbox
//在運行時創建列表,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 ::我正在將asp.net Webform與實體框架一起使用
您可以輕松地遵循該示例,並添加具有“ true”值的復選框控件。 問題是未選中的復選框不會作為表單值傳遞,因此如果表單名稱不存在於表單發布中,則可以將其設置為默認的“ false”,也可以在復選框字段之后設置隱藏的默認值並使用第一個通過的值
MVC中的模型綁定將為您做到這一點https://stackoverflow.com/a/14731571/60669
由於腳本只是查看服務器控件,因此它甚至更簡單
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"
}
對於列表框,您必須將SelectionMode設置為multiple並將大小設置為可渲染。 在回發時,如果SelectionMode為多個,則需要循環這些項目並連接結果。
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);
}
由於語法錯誤,列表框未呈現,通常工作的代碼在這里
//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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