In classic ASP if you wanted to send a user to a specific page you would send/create a URL like : posts.asp?id=24 ...the querystring indicating the post.
Well, in asp.net using a DetailsView control bound to a dataset, how do I do the same thing?
In the address bar, all i see is posts.aspx when I'm paging through the records, no querystring part. How do I send a user to posts.aspx?id=24 when its a detailsview control on the page.
Note: I'm interested in sending a user to a specific postid not a specific index in the dataset.
Regards
Melt
A quick way to do this would be to bind your details view in page load as:
string id = Request.QueryString["id"];
if(!string.IsNullOrEmpty(id))
{
myDataSet.Filter = String.Format("id = {0}", id);
}
myDetailsView.DataSource = myDataSet;
myDetailsView.DataBind();
MSDN has more information on filtering and sorting DataSets.
Edit: In order to change to a specific page, maybe do something like this in page load:
int selectedPage = -1;
string id = Request.QueryString["id"];
if(!string.IsNullOrEmpty(id))
{
for(int i = 0; i< myDataSet.Tables[0].Rows.Count; i++)
{
DataRow row = myDataSet.Tables[0].Rows[i];
if(row["id"].ToString().Equals(id))
{
selectedPage = i;
continue;
}
}
}
myDetailsView.DataSource = myDataSet;
myDetailsView.PageIndex = selectedPage;
myDetailsView.DataBind();
Related
On Static WebMethod I'm unable to get ListBoxcontrol, so I have stored that control in session on Page_Load event as:
HttpContext.Current.Session["LB_AvailFields"] = lbavailablefields;
After calling WebMethod I'm getting values from Database and trying to fill ListBox but ListBox not showing any values.
Following is hardcoded testing code which works fine on Page_Load but not in WebMethod please suggest where I'm going wrong?
List<MyListItem> LB = new List<MyListItem>();
MyListItem lbitem;
for(int i= 0;i<5;i++)
{
lbitem = new MyListItem();
lbitem.PMKey = "Key" + i;
lbitem.PMSystemName = "SystemName: " + i;
LB.Add(lbitem);
}
ListBox lbox = (ListBox)HttpContext.Current.Session["LB_AvailFields"];
lbox.DataSource = LB;
lbox.DataTextField = "PMSystemName";
lbox.DataValueField = "PMKey";
lbox.DataBind();
The WebMethod concept is to give you a quick web service like experience. The web page doesn't exist on the server, as it does when Page_Load works. The intended use is to call web methods from client script, return data to client side and consume there (javascript)
[WebMethod]
[ScriptMethod(ResponseFormat = ResponseFormat.Json)]
public MyReturnResultObject[] GetListBoxData()
{
List<MyReturnResultObject> result = new List<MyReturnResultObject>();
loop to fill your return result
{
var oneResult = new MyReturnResultObject();
...
result.Add(oneResult);
}
return result.toArray();
}
Then on the client side, where you use javascript to call that method, just use the returned json to populate your listbox (using javascript). There are many ways to do this in javascript, showing most rudimentary; if jQuery is available to you you could use it.
var myList = ...; // obtain a reference to your list box
var anOption;
loop through json
anOption = document.createElement("Option");
anOption.text = ...; //from json
anOption.value = ...; //from json
myList.add(anOption);
I want to create dynamic text boxes during run time.
Suppose im gettng a text from a database as "# is the capital of India" now i want to replace that "#" by text box while it is rendered to user as below
<asp:TextBox runat="server" id = "someid"></asp:TextBox> is the capital of India
Im able to get the textbox and text as combination. However I cannot access the textboxes with the given id and when any event occurs on the page the textboxes are lost as they logically does not exist untill their state is stored.
I also went through the concepts of place holder and Viewstate to store the dynamically created controls and make their id's available for the methods, but as far as I tried I could not meet the textbox and text combination requirement.
Im looping over the entire text recieved from database and checking if there is any"#". Is yes then i want to replace it with a textbox on which i can call methods to take back the value entered in the text box to database and store it.
eg: text is "#" is the capital of India
for (int i = 0; i < que.Length; j++) //que holds the text
{
if (que[i] == '#')
{
//Textbox should be created
}
else
{
//the texts should be appended before or after the textbox/textboxes as text demands
}
}
On button click I'm passing request to database, which will send me necessary details i.e. question text, options and also saves the current checked value etc.
protected void BtnLast_Click(object sender, EventArgs e)
{
CheckBox1.Checked = false;
CheckBox2.Checked = false;
CheckBox3.Checked = false;
CheckBox4.Checked = false;
QuestionSet q = new QuestionSet();
StudentB b = new StudentB();
q = b.GetQuestion(1, 1, qid, 'L', 0, Checked, date);
qid = Convert.ToInt32(q.Question_Id);
Checked = q.Checked;
if (q.Question_Type == 11) //indicates its objective Question
{
//ill bind data to checkboxes
}
else if (q.Question_Type == 12) // indicate its fill in the blanks question
{
for (int j = 0; j < que.Length; j++)
{
if (que[j] == '#')
{
count++;
string res = "<input type = 'text' runat = 'server' id ='TxtBoxFillUp" + count + "'/>";
htm = htm.Append(res);
}
else
{
htm = htm.Append(que[j]);
}
}
}
}
Any help will be greatly appreciated, thanks in advance.
Adding control in the way you do it won't create control as asp.net creates it. You do have to create controls as usual .net object.
TextBox myNewTextBox = new TextBox() {};
// Set all initial values to it
And add this cotrol to placeholder or panel, whatever you use. Keep in mind that asp.net page events fire even if you use update panel, so in order to maintain state and events of newly created controls you have take care of creating such controls long before page's Load event fires. Here is my answer to another simialiar question.
Seeing the requirements you have:
1.) You need to use JavaScript. Since the ASP.NET will not recreate controls which are dynamically added. Dynamically added controls need to be recreated after every postback. This is the reason why your TextBoxes are Lost after every postback.
2.) You can write JavaScript code to Hide and show the textboxes for blank texts since at every button click you can call Client side functions using: OnClientClick() property of buttons.
3.) Also to Get the TextBoxes using ID property, add them in Markup( .aspx ) portion itself.
i have created dynamic listboxes (4 to 10) in ASP.NET.
and my question is , How do i find the dynamically created listboxes using c#?
thanks
Sure... and i appreciate your help . below code i am using for creating dynamic LB
protected void btndyfilter_Click(object sender, EventArgs e)
{
int numberOfListBox = lbFilter.GetSelectedIndices().Length;
string lbname = lbFilter.SelectedValue;
for (int i = 0; i < numberOfListBox; i++)
{
ListBox listb = new ListBox();
ListItem lItem = new ListItem();
listb.SelectionMode = System.Web.UI.WebControls.ListSelectionMode.Multiple;
listb.Height = 150;
listb.Width = 200;
lItem.Value = i.ToString();
lItem.Text = lbname;
listb.Items.Add(lItem);
panFilter.Controls.Add(listb);
//once we created the LB dynamically i need to populate each LB with the corresponding values
connstr2 = System.Configuration.ConfigurationManager.ConnectionStrings["connstr"].ConnectionString;
conn2.ConnectionString = connstr2;
conn2.Open();
CubeCollection CubeList = conn2.Cubes;
string cb = ddlCubeList.SelectedItem.Text;
//need to remove the Hardcoded Code
foreach (Member dimem in CubeList[cb].Dimensions["Date"].Hierarchies["Calendar Date"].Levels["Date"].GetMembers())
{
ListItem Memlist = new ListItem();
Memlist.Text = dimem.UniqueName;
lbFilter.Items.Add(Memlist);
}
}
panFilter.Visible = true;
panCubeDef.Visible = true;
}
so this will create the LB i believe :)... and Inside the commented code i need to use to populate for each LB item ..perhaps it bit hardcoded which i need to remove. so i all dynamic LBs are populated then the selected items from all LBs will come into the where clause in my MDX query..hope i did not confuse you
There is 2 way either you can store dynamic control detail with dictionary or just find when you want to use it using some code like this
Control GetControlByName(string Name)
{
foreach(Control c in this.Controls)
if(c.Name == Name)
return c;
return null;
}
while generating ListBox dynamically, give ListBox ID as:
lstBoxNo1, lstBoxNo2. lstBoxNo3 etc. where 1,2,3(no) will be from count.
like
int count=1;
generate listbox control
listboxid=lastBoxNo+count;
count++
`by doing this, u have control over id's.
else use
http://stackoverflow.com/questions/3731007/using-findcontrol-to-find-control
using this link to understand findcontrol.
The points that you wont to find that dynamic controls are.
The moment you first render the page.
On every other post back.
In the case of 1, then you better keep a variable on your page that keep that creations.
In the case of 2, when you have post back, you need to store somehow the creations of your control in the page when you render it. One good place is to keep that information on the viewstate.
You can also on the post back, just to check if you have any post back valued from controls that you have named with a serial numbering starting from 1, eg You start looking if you have post back from ControlName_1, then ControlName_2, and when you not found any other value you end.
I am having user control registered on a aspx page.
there is a button on user control resisted on some aspx page that perform some action to store the value of viewste to the database, and below that i have cleared my viewstate value, but if i do right click and reload the page it reinsert the values to the data base, what i am missing or the viewstate do not get cleared, how should i prevent it to resave the same entries to the database.
I am partially writing my code below.
protected void btnFinish_Click(object sender, EventArgs e)
{
if (ViewState["dtQuestions"] != null)
{
foreach (DataRow dr in dtQuestions.Rows)
{
int currQueScore = GetAnswerScore(dr["AnswerType"].ToString().Trim(), dr["ClientAnswerValue"].ToString().Trim());
dr["ClientAnswerScore"] = currQueScore;
myScore += currQueScore;
SurveyClientAnswer objDetail = new SurveyClientAnswer();
objDetail.SurveyClientID = objMaster.SurveyClientID;
objDetail.QuestionID = int.Parse(dr["QuestionID"].ToString());
objDetail.Answer = dr["ClientAnswerValue"].ToString();
objDetail.Score = int.Parse(dr["ClientAnswerScore"].ToString());
DB.SurveyClientAnswers.InsertOnSubmit(objDetail);
DB.SubmitChanges();
}
objMaster.FinalScore = myScore;
DB.SubmitChanges();
ViewState["dtQuestions"] = null;
}
else
{
ModalPopupExtender1.Show();
pnl.Visible = true;
}
}
If you don't want to reinsert the data, simply create a unique constraint on the database to disallow this scenario.
As far as doing it in code, you could possibly only insert the data adding this condition to the if statement:
if(IsPostBack && (ViewState["dtQuestions"] != null)
{
//meaning the user is not simply reloading the page but actually posting back
}
Note that there might be some corner cases where this won't work. Without testing is difficult to know but I strongly believe that this should be handled at the database level instead.
I know this has been asked before, but I've found a different way to get references to controls in external JS files but I'm not sure how this would go down in terms of overall speed.
My code is
public static void GenerateClientIDs(Page page, params WebControl[] controls) {
StringBuilder script = new StringBuilder();
script.AppendLine("<script type=\"text/javascript\">");
foreach (WebControl c in controls) {
script.AppendLine(String.Format("var {0} = '#{1}';", c.ID, c.ClientID));
}
script.AppendLine("</script>");
if (!page.ClientScript.IsClientScriptBlockRegistered("Vars")) {
page.ClientScript.RegisterClientScriptBlock(page.GetType(), "Vars", script.ToString());
}
}
This was I can reference the id of the aspx page in my JS files.
Can anyone see any drawbacks to doing things this way? I've only started using external JS files. Before everything was written into the UserControl itself.
Well, the method can only be used once in each page, so if you are calling it from a user control that means that you can never put two of those user controls on the same page.
You could store the control references in a list until the PreRender event, then put them all in a script tag in the page head. That way you can call the method more than once, and all client IDs are put in the same script tag.
Something like:
private const string _key = "ClientIDs";
public static void GenerateClientIDs(params WebControl[] controls) {
Page page = HttpContext.Current.Handler As Page;
List<WebControl> items = HttpContext.Current.Items[_key] as List<WebControl>;
if (items == null) {
page.PreRender += RenderClientIDs;
items = new List<WebControl>();
}
items.AddRange(controls);
HttpContext.Current.Items[_key] = items;
}
private static void RenderClientIDs() {
Page page = HttpContext.Current.Handler As Page;
List<WebControl> items = HttpContext.Current.Items[_key] as List<WebControl>;
StringBuilder script = new StringBuilder();
script.AppendLine("<script type=\"text/javascript\">");
foreach (WebControl c in items) {
script.AppendLine(String.Format("var {0} = '#{1}';", c.ID, c.ClientID));
}
script.AppendLine("</script>");
page.Head.Controls.Add(new LiteralControl(script));
}
Check this out: http://weblogs.asp.net/joewrobel/archive/2008/02/19/clientid-problem-in-external-javascript-files-solved.aspx
Looks like it takes care of the dirty work for you (something like Guffa's answer). It generates a JSON object (example) containing server IDs and client IDs, so you can do something like this in your JavaScript:
var val = PageControls.txtUserName.value;