How do i manipulate a string/dataitem in my Listview? - c#

This is how i am showing the string in listview:
<%# Eval("Description")%>
This is the code in a method to get the data for listview :
lstBlog.DataSource = blg;
lstBlog.DataBind();
How can i manipulate the "Description" string ... i.e. get only first 50 characters/stripping off any html tags from the string .......
Thanx in advance

in aspx page
<%# CutString(Eval("Description").ToString(),50) %>
in cs
public string CutString(string value , int len)
{
// ....
}

In aspx page, you can directly take string part as below:
<%# Convert.ToString(Eval("Description")).Substring(0, 50) %>
"OR"
In aspx page and create ItemDataBound event for the ListView
<asp:Label ID="lblDescription" runat="server" Text=""></asp:Label>
In code behind, create ItemDataBound
protected void lvData_ItemDataBound(object sender, ListViewItemEventArgs e)
{
if (e.Item.ItemType == ListViewItemType.DataItem)
{
Blog blg = (Blog)e.Item.DataItem;
Label lblDescription = (Label)e.Item.FindControl("lblDescription");
lblDescription.Text = blg.Description.Substring(0, 50);
}
}
To strip HTML tags please see here: http://www.dotnetperls.com/remove-html-tags

Related

GridView not displaying on webpage

I am trying to use gridview to display data from my database but I can't seem to get the gridview to display on the page. I inserted a breakpoint and the gridview shows the correct number of rows in the data source, and the correct number of rows in the gridview after databind. I am still not getting any display on the webpage, when inspecting where it should be with chrome I see the header tag but nothing related to the gridview. What am I doing wrong?
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
string id = Request.QueryString["profileID"];
GridView achievementTable = new GridView();
AchievementDatabaseTableAdapters.UserGamesTableAdapter UserGamesAdapter = new AchievementDatabaseTableAdapters.UserGamesTableAdapter();
AchievementDatabase.UserGamesDataTable userGames = UserGamesAdapter.GetUserGames();
achievementTable.DataSource = userGames.Select("ProfileID =" + id).CopyToDataTable();
achievementTable.DataBind();
}
}
.aspx code
<%# Page Title="Profile" Language="C#" AutoEventWireup="true" CodeBehind="Profile.aspx.cs"
MasterPageFile="~/Site.Master" Inherits="AchievementProject.Profile" %>
<asp:Content ID="ProfileContent" ContentPlaceHolderID="MainContent" runat="server">
<h2><%: Title %></h2>
<asp:Gridview ID="achievementTable" runat="server" AutoGenerateColumns="True"
ShowHeaderWhenEmpty="true" EmptyDataText="Failed"></asp:Gridview>
</asp:Content>
achievementTable is local to the page load event. Move it to at least a protected variable at the class level and it will be available to your views.

tooltip computed links for asp button after button is clicked

<ItemTemplate>
<tr>
<asp:LinkButton ID="btnID" runat="server"
ToolTip='The calculated IDs are: ' OnCommand="showIds"
CommandArgument='<%# Convert.ToInt32(Eval("Year")) + "," +
Convert.ToInt32(Eval("Month")) %>'>
<%# Convert.ToInt32(Eval("Count")) - Convert.ToInt32(Eval("LittleCount"))%>
</asp:LinkButton>
</tr>
</ItemTemplate>
As you can notice the tooltip text is static. In code behind, I do calculate and get some integers ( IDs ) every time the above button is clicked ( protected void showIds(object sender, CommandEventArgs e) { .... }) contained as a List<ExpressionListDictionary>. ( the asp:LinkButton is contained inside an asp:ListView )
What I want to do, is to change the tooltip into a dynamic one, containing all the already obtained IDs as links. ( Something like this: http://jsfiddle.net/IrvinDominin/jLkcs/5/ - but in my case I do need firstly to click the button for calculating the IDs, and after this I would need to change the tooltip text from code as it needs to show the respective IDs, as links if it is possible)
How can I achieve this?
If you have a class (or id or something) to identify the buttons you can make an jQuery document ready function to change the tooltip with ids to a link containing the ids.
I modifyed your fiddle: http://jsfiddle.net/jLkcs/545/
$(document).ready(function () {
$(".myLinkButton").each(function() {
createlink(this);
});
});
function createlink(obj){
var ids= $(obj).attr('title');
var linkHtml="<a href='javascript:alert(" + ids + ")'>link</a>"
$(obj).attr('title',linkHtml);
}
Why not simply adjust the ToolTip in the codebehind during postback?
protected void showIds(object sender, CommandEventArgs e)
{
((LinkButton)sender).ToolTip = "blahblah";
}
You can set your sender attributes if the CommandEventArgs CommandName is equal with your defined one
public void LinkButton_Command(Object sender, CommandEventArgs e)
{
if (e.CommandName.Equals("showIds"))
{
//
}
}
Here is an working example, this will work, not counting in what user control LinkButton is used:
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class _Default : Page
{
public string btnNoTooltip = "No IDs are calculated";
public string btnTooltip = "The calculated IDs are:";
protected void Page_Load(object sender, EventArgs e)
{
}
public void LinkButton_Command(Object sender, CommandEventArgs e)
{
if (e.CommandName.Equals("LinkButtonOrder"))
{
LinkButton lkTrigger = (LinkButton)sender;
if (lkTrigger.ToolTip.Equals(btnNoTooltip))
{
lkTrigger.ToolTip = btnTooltip + " " + e.CommandArgument;
}
else
{
lkTrigger.ToolTip += " " + e.CommandArgument;
}
Random random = new Random();
lkTrigger.CommandArgument = random.Next(0, 100).ToString();
Label1.Text = "Triggered: " + e.CommandName + " with Argument " + e.CommandArgument;
}
}
}
Markup:
<%# Page Title="Home Page" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<asp:Content ID="BodyContent" ContentPlaceHolderID="MainContent" runat="server">
<h3>LinkButton Command Event Example</h3>
<asp:LinkButton id="LinkButton1"
Text="Order Item Here"
CommandName="LinkButtonOrder"
ToolTip='No IDs are calculated'
CommandArgument="01"
OnCommand="LinkButton_Command"
runat="server"/>
<br />
<asp:LinkButton id="LinkButton2"
Text="Or Order Item Here"
CommandName="LinkButtonOrder"
CommandArgument="02"
ToolTip='No IDs are calculated'
OnCommand="LinkButton_Command"
Runat="server"/>
<br />
<br />
<asp:Label id="Label1" runat="server"/>
<asp:PlaceHolder id="plhInjectId" runat="server" Visible="false"></asp:PlaceHolder>
</asp:Content>
You can use jquery to generate Tool Tip on Page itself.
Add a hidden field for your all the already obtained IDs (comma sepearted) to asp:ListView
Populate this hidden in ItemCreated event on server
add a class to your link button, say 'ShowHyperlinkOnHover'
Bind mouseenter event to class ShowHyperlinkOnHover document.ready function of jquery, this will dynamically generate tool tip. and then on Mouse Over tool tip will be displayed.
$(document).ready(function () {
$(document).on("mouseenter", ".ShowHyperlinkOnHover", function(this){
// 2 is index of hidden field having comma seperated Ids
var dynaToolTip;
$(this).parent("td:nth-child(2)").split(',').each(
function(oneId) dynaToolTip=dynaToolTip+ anyFomationLogic(oneId);
);
$(this).attr('title',dynaToolTip);
});
});

Values in dynamically added controls not retained on postback

I have a page with a number of controls of type MyControl added dynamically. The count is stored in the ViewState, and only incremented with a button click.
In MyControl, I have a TextBox control, and a Label control. When the text is changed in the textbox, the value is multiplied by 2 and displayed in the label control.
To do this, I have added an OnTextChanged event and set AutoPostBack to true.
My problem is this: when I have any number of MyControl's on the page, and change the text in any of the textboxes, the label is updated and the values are retained on postback.
However, if I click the increment button on the page, all the values in the textboxes and labels are lost.
My code:
Default.aspx
<%# Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="Test.Default" EnableViewState="true" %>
<html>
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
Count:
<asp:Label ID="lblCount" runat="server"></asp:Label>
<asp:Button ID="btnAdd" runat="server" OnClick="btnAdd_Click" Text="+" />
<asp:Panel ID="pnlControls" runat="server"></asp:Panel>
</form>
</body>
</html>
Default.aspx.cs
public partial class Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
int count = 0;
//if not postback, then set count and store in viewstate
if (!Page.IsPostBack)
{
count = 1;
ViewState["count"] = count;
}
LoadControls();
}
protected void btnAdd_Click(object sender, EventArgs e)
{
//increment count
ViewState["count"] = (int)ViewState["count"] + 1;
pnlControls.Controls.Clear();
LoadControls();
}
private void LoadControls()
{
//add controls to page
for (int i = 0; i < (int)ViewState["count"]; i++)
{
MyControl con = (MyControl)LoadControl("MyControl.ascx");
con.ID = i.ToString();
pnlControls.Controls.Add(con);
}
//set count label
lblCount.Text = ViewState["count"].ToString();
}
}
MyControl.ascx
<%# Control Language="C#" AutoEventWireup="true" CodeBehind="MyControl.ascx.cs" Inherits="Test.MyControl" EnableViewState="true" %>
<div>
<asp:TextBox ID="txtField" runat="server" OnTextChanged="txtField_TextChanged" AutoPostBack="true"></asp:TextBox>
<asp:Label ID="lblAnswer" runat="server" Text="answer:"></asp:Label>
</div>
MyControl.ascx.cs
public partial class MyControl : System.Web.UI.UserControl
{
public string Text;
protected void Page_Load(object sender, EventArgs e)
{
}
protected void txtField_TextChanged(object sender, EventArgs e)
{
lblAnswer.Text = (int.Parse(txtField.Text) * 2).ToString();
}
}
Am I missing something obvious? How can I keep the values when the button is clicked?
The reason you lose the info of MyControl(s..) is when you click the button you clear them:
pnlControls.Controls.Clear();
If you want to keep the values I recomended you to use Session variables, for example an array when you fire "txtField_TextChanged" to save "lblAnswer.Text", be carefull with the ID's to differentiate from each other in the Session variable.
Finally, I'd put "LoadControls();" inside Page_Load, outside I think It's redundant.

Find Control Inside ListView Control

I want to find "Label" control with ID = "Label" inside the "ListView" control. I was trying to do this with the following code:
((Label)this.ChatListView.FindControl("Label")).Text = "active";
But I am getting this exception: Object reference not set to an instance of an object .
What is wrong here ?
This is aspx code:
<asp:ListView ID="ChatListView" runat="server" DataSourceID="EntityDataSourceUserPosts">
<ItemTemplate>
<div class="post">
<div class="postHeader">
<h2><asp:Label ID="Label1" runat="server"
Text= '<%# Eval("Title") + " by " + this.GetUserFromPost((Guid?)Eval("AuthorUserID")) %>' ></asp:Label></h2>
<asp:Label ID="Label" runat="server" Text="" Visible="True"></asp:Label>
<div class="dateTimePost">
<%# Eval("PostDate")%>
</div>
</div>
<div class="postContent">
<%# Eval("PostComment") %>
</div>
</div>
</ItemTemplate>
</asp:ListView>
Listview is a databound control; so controls inside it will have different ids for different rows. You have to first detect the row, then grab the control. Best to grab such controls is inside an event like OnItemDataBound. There, you can do this to grab your control:
protected void myListView_ItemDataBound(object sender, ListViewItemEventArgs e)
{
if (e.Item.ItemType == ListViewItemType.DataItem)
{
var yourLabel = e.Item.FindControl("Label1") as Label;
// ...
}
}
If you want to grab it in Page_Load, you will have to know specific row and retrieve the control as:
var theLabel = this.ChatListView.Items[<row_index>].FindControl("Label1") as Label;
This function will get Author Name from a database, you just need to call your method to get Author Name and then return it
protected string GetUserFromPost(Guid? x)
{
// call your function to get Author Name
return "User Name";
}
And to bind label in the list view you have to do it in list view ItemDataBound Event
protected void ChatListView_ItemDataBound(object sender, ListViewItemEventArgs e)
{
if (e.Item.ItemType == ListViewItemType.DataItem)
{
Label lbl = e.Item.FindControl("Label") as Label;
lbl.Text = "Active";
}
}
Here are the list view aspx code changes (just add onitemdatabound="ChatListView_ItemDataBound"):
asp:ListView
ID="ChatListView"
runat="server"
DataSourceID="EntityDataSourceUserPosts"
onitemdatabound="ChatListView_ItemDataBound"
It should be Label1 in the arguement:
((Label)this.ChatListView.FindControl("Label1")).Text = "active";
This should be in a databound event.
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.listview.itemdatabound.aspx
Try it:
protected void ChatListView_ItemDataBound(object sender, ListViewItemEventArgs e)
{
if (e.Item is ListViewDataItem)
{
var yourLabel = e.Item.FindControl("Label1") as Label;
// ...
}
}
One simple solution to this problem, which avoids the FindControl code is to place OnInit on your label.
This would change your page code to this: <asp:Label ID="Label" runat="server" Text="" Visible="True" OnInit="Label_Init"></asp:Label>
And in your code behind you will now have a function like this:
protected void Label_Init(object sender, EventArgs e)
{
Label lblMyLabel = (Label)sender;
lblMyLabel.Text = "My Text";
}

Retrieve contents of HtmlGenericControl inside ASCX WebControl

I have an HtmlGenericControl which is a simple DIV with runat=server
This Control is embedded inside of an ASCX WebControl which resides on multiple pages. At Page_Load this element is populated by a repeater that is data-bound to database data that is Page Specific.
The trouble I'm having is ASCX WebControls don't seem to read the contents of their own elements very easily.
So far this has failed:
How do I get the HTML output of a UserControl in .NET (C#)?
I'm looking for a way to get the contents of the HtmlGenericControl inside of a button click. How would I do that?
Simplifying previous question. Retrieve HTML of specific element in ASCX
OK, I got it working (I think...)
Output
ASPX Code behind
public override void VerifyRenderingInServerForm(Control control)
{
//base.VerifyRenderingInServerForm(control);
}
ASPX markup
%# Page EnableEventValidation="false" .....
User control code behind
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
var d = new QuestionsContext().GetQuestions();
this.repeater.DataSource = d;
this.repeater.DataBind();
}
}
protected void getContent_Click(object sender, EventArgs e)
{
var sb = new StringBuilder();
this.generic.RenderControl(new HtmlTextWriter(new StringWriter(sb)));
string s = sb.ToString();
this.Trace.Warn(Server.HtmlEncode(s));
this.message.Text = Server.HtmlEncode(s);
}
User control markup
<div runat="server" id="generic">
<asp:Repeater runat="server" ID="repeater" >
<ItemTemplate>
<%# Eval("QuestionText") %>
</ItemTemplate>
</asp:Repeater>
</div>
<br />
<asp:Button Text="Get content" ID="getContent" runat="server" OnClick="getContent_Click" />
<br />
<asp:Label ID="message" runat="server" />

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