I have a ListView which displays event bookings. If there is a time slot available, I want to make a booking button visible beside that data item. I have tried doing this in both the OnItemCreated and OnItemDataBound event handlers to no avail.
In this particular scenario, there are four results and all are available. However, the button only appears beside the last result. It's like something is being overwritten. I tried setting the ID property to something different in each round of the loop but that failed at runtime.
I also tried flipping the logic by setting the visibility of the button to false in the markup initially - three buttons would appear and no button beside the last data item.
I originally tried storing the Button control in ViewState and got the "not serializable" error. So I switched to storing the object in Session state.
Can someone point me in the right direction?
<ItemTemplate>
...
<asp:Button ID="reserveButton" Text="Book Now" Visible="false"
OnClick="ReserveButton_Click" runat="server" />
</ItemTemplate>
// After the DataBind() method in the search button handler
...
int rowCount = resultsDS.Tables[0].Rows.Count;
for (int i = 0; i < rowCount; i++)
{
if (resultsDS.Tables[0].Rows[i]["Available"].ToString().Contains("Available Time Slots"))
{
reserveButton = Session["ReserveButton"] as Button;
reserveButton.Visible = true;
}
}
...
protected void ResultsList_ItemCreated(object sender, ListViewItemEventArgs e)
{
if (e.Item is ListViewItem)
{
reserveButton = e.Item.FindControl("reserveButton") as Button;
Session["ReserveButton"] = reserveButton;
}
}
For the benefit of others, I was able to solve this as follows:
protected void ResultsList_ItemDataBound(object sender, ListViewItemEventArgs e)
{
if (e.Item is ListViewItem)
{
DataRowView row = (DataRowView)e.Item.DataItem;
if (row["Available"].ToString().Contains("Available Time Slots"))
{
Button reserveButton = e.Item.FindControl("reserveButton") as Button;
reserveButton.Visible = true;
}
}
}
Related
I'm trying to have a user/admin scenario for editing a formview. What I have is the Edit buttons in the formview be visible=true by default. Then I use a statement which says if the role is not equal to admin, then set the visibility to false for the edit button. It works like it should, when I click around, do postbacks, etc. the items stay hidden if the user is and admin...except when I use a dropdown list for filtering, which uses a statement like dataSource1.FilterExpression = ("ID=" + ddl1.SelectedValue).
Whether I set the default visibility to true or false for the formview edit linkbutton, when using the FilterExpression, it changes the visibility of what I don't want it to be. It is because the FilterExpression sets the visibility of the control to whatever the default visibility property of the control is set to.
Below is some code as an example of what I mean. Please help!
protected void Page_PreRender(object sender, EventArgs e)
{
string role;
role = "client";
LinkButton editGeneralOverview = (LinkButton)formViewGeneralOverview.FindControl("EditButton");
if (role != "admin"))
{
editGeneralOverview.Visible = false;
}
if (ddlIDFilter.SelectedValue != "-- ALL --")
{
dataSourceGeneralOverview.FilterExpression = ("ID=" + ddlIDFilter.SelectedValue);
}
You could hide it in the FormViews DataBound event:
protected void formViewGeneralOverview_DataBound(Object sender, EventArgs e)
{
LinkButton editGeneralOverview = (LinkButton)formViewGeneralOverview.FindControl("EditButton");
if (role != "admin"))
{
editGeneralOverview.Visible = false;
}
}
This way your visibility setting gets (re)applied after the FilterExpression has already taken effect.
Note: in case you do not know, you can attach this event to the FormView in the markup by setting the OnDataBound property. Like this:
<asp:FormView ID="formViewGeneralOverview"
OnDataBound="formViewGeneralOverview_DataBound"
...whatever other propeties you have >
...templates and junk...
</asp:FormView>
i had a DataList view which i add a check box in the Item Template
i want each item i select to increase some counter for examble once it's checked ..
i used the following code to handle that ,but the event function is never accessed ?!
protected void selectItemCheckBox_CheckedChanged(object sender, EventArgs e)
{
int selected = 0;
foreach (DataListItem i in DataList1.Items)
{
CheckBox chk = (CheckBox)i.FindControl("selectItemCheckBox");
if (chk.Checked)
{
selected++;
}
selectedItemCount.Text = Convert.ToString(selected);
}`
}
Currently you're looping over every checkbox for every checked checkbox which is inefficient and depending on your other code, may be causing trouble.
You're better off incrementing for each checkbox individually.
...DataList...
<ItemTemplate>
<asp:CheckBox id="selectItemCheckBox" runat="server"
AutoPostBack="True"
OnCheckedChanged="selectItemCheckBox_CheckedChanged" />
</ItemTemplate>
...DataList...
After a box is checked, update the total for just that checkbox using sender
protected void selectItemCheckBox_CheckedChanged(object sender, EventArgs e)
{
// Parse the total selected items from the TextBox.
// You may consider using a Label instead, or something non-editable like a hidden field
int totalChecked;
if (int.TryParse(selectedItemCount.Text, out totalChecked) = false)
totalChecked = 0;
// Get a reference to the CheckBox
CheckBox selectItemCheckBox = (CheckBox)sender;
// Increment the total
if (selectItemCheckBox.Checked == true)
totalChecked++;
// Put back in the TextBox
selectedItemCount.Text = totalChecked.ToString();
}
Is there any ways to create reset button to clear all text in text fields in asp form? When user hits the reset button, all text entered by them will clear and they are enable to enter back text in the area.
As per my knowledge there is no such reset functionality provided by Asp.Net.
We can achieve the reset like this
btnReset.Attributes.Add("onClick", "document.forms[0].reset();return false;");
Or
Like this
<input type='button' id='resetButton' value='Reset' onclick='theForm.reset();return false;'/>
Or OnClientclick of asp.net button use this theForm.reset();return false;
try this create a button with reset and in click event write ClearInputs(Page.Controls); and event will call this method.
protected void Button2_Click(object sender, EventArgs e)
{
ClearInputs(Page.Controls);
}
void ClearInputs(ControlCollection ctrls)
{
foreach (Control ctrl in ctrls)
{
if (ctrl is TextBox)
((TextBox)ctrl).Text = string.Empty;
ClearInputs(ctrl.Controls);
}
}
In the button click method, set all textbox.text.length values to 0. either do it one by one, which is the simple way, or do it by getting all controls of type textbox on the page, which is tad bit more sophisticated, but could be much less typing, depending on the number of textboxes. Definitely more maintainable.
private void ChangeBtn_Click(object sender, EventArgs e)
{
foreach(Control c in Page.Controls)
{
if (c.Controls.Count > 0)
{
foreach(Control c2 in c.Controls)
{
if (c2.GetType().ToString() == "System.Web.UI.WebControls.TextBox")
{
myspan.InnerHtml = ((TextBox)c2).Text;
((TextBox)c2).Text = ""; //or ((TextBox)c2).Text.Length = 0;
}
}
}
}
}
http://msdn.microsoft.com/en-us/library/20zys56y(v=vs.90).aspx
Create a Click event to the Button control and use the following codes below:
foreach (Control control in Page.Controls)
{
if (control is TextBox)
{
TextBox txt = (TextBox)control;
txt.Text = "";
}
}
This will save you some time to clear all the textboxes inside the web form.
Use Jquery the easiest way to find any type of control and will not have post back event.
$('input[type=text], textarea')
Use foreach loop for clearing value.
Please note that
btnReset.Attributes.Add("onClick", "document.forms[0].reset();return false;");
will not work in clearing pages that are posted back, i.e. If a text box had a value "Silly me" and has been posted back, this code will reset to the post back value which is "Silly me".
The workaround is to repost the page with cleared values - try the following code (it worked for me)
OnClientClick="document.location.href=document.location.href;"
will reload the page with cleared values...
I have multiple type of inputs in my page (TextBox, DropDownList and CheckBox), so here is how I reset them all
Put an <asp:Panel> that wraps my inputs
Run BtnClear_Click on Clear button click
Loop each inputs and reset text/selection/checked value by types
The codes
Default.aspx
<asp:Panel ID="PanelReport" runat="server">
...
<asp:TextBox ID="fldSpeedoMula" runat="server"></asp:TextBox>
<asp:DropDownList ID="ddlPlateNo" runat="server" CssClass="form-control"></asp:DropDownList>
<asp:CheckBox ID="cbCard" runat="server" />
<asp:CheckBox ID="cbCash" runat="server" />
<asp:Button ID="BtnClear" runat="server" Text="Clear" CssClass="button" OnClick="BtnClear_Click"/>
...
</asp:Panel>
Default.aspx.cs
protected void BtnClear_Click(object sender, EventArgs e)
{
// Clear all inputs
foreach (DropDownList ddl in PanelReport.Controls.OfType<DropDownList>())
{
ddl.SelectedIndex = 0;
}
foreach (TextBox fld in PanelReport.Controls.OfType<TextBox>())
{
fld.Text = string.Empty;
}
foreach (CheckBox cb in PanelReport.Controls.OfType<CheckBox>())
{
cb.Checked = false;
}
}
I am using a Listview in a usercontrol that I databind to a list of object in the page load event.
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack) return;
BindListViews();
}
private void BindListViews()
{
MyListView.DataSource = IncludeExpressions;
MyListView.DataBind();
}
I need to handle inserting new items in the list.
To do that, I added an InsertItemTemplate with a button that has "Insert" as command argument.
I dont want to persist the data to the database until the user press the save button, at the bottom of the form.
So in the ItemCommand event, Here is my code:
protected void Expression_ItemCommand(object sender, ListViewCommandEventArgs e)
{
var listView = (sender as ListView);
var expressions = GetExpressions(listView);
var newExpression = new Expression
{
CaseSensitive = ((CheckBox)e.Item.FindControl("CaseSensitiveCheckBox")).Checked,
SearchText = ((TextBox)e.Item.FindControl("SearchTextTextBox")).Text,
Scope = (Scope)Enum.Parse(typeof(Scope), ((DropDownList)e.Item.FindControl("ScopeDropDownList")).SelectedValue, true),
Type = (Type)Enum.Parse(typeof(Type), ((DropDownList)e.Item.FindControl("TypeDropDownList")).SelectedValue, true),
};
expressions.Add(newExpression);
listView.DataSource = expressions;
listView.DataBind();
UpdatePanelInclude.Update();
}
private List<Expression> GetExpressions(ListView lv)
{
var expressions = new List<Expression>();
foreach (var row in lv.Items)
{
var searchText = ((TextBox)row.FindControl("SearchTextTextBox")).Text;
...
expressions.Add(new Expression
{
CaseSensitive = caseSensitive,
Scope = scope,
Type = type,
SearchText = searchText
});
}
return expressions;
}
This works perfectly fine until I add an UpdatePanel around the listview.
When I add an updatepanel, the Expression_ItemCommand handler is hit only every 2 clicks, eventhough the page is post back every click.
While debugging, I can see that I do enter the Page_Load event of the page at each click on the Insert button, but it hits the Expression_ItemCommand only every 2 clicks. and reset the content of my listview when the ItemCommand is not hit.
I smell ViewState problems here, but I can't figure out how to fix it.
Here is what the markup looks like :
<asp:UpdatePanel ID="UpdatePanelInclude" UpdateMode="Conditional" ChildrenAsTriggers="true" runat="server">
<asp:ListView ID="MyListView" OnItemCommand="Expression_ItemCommand" OnItemInserting="ExpressionInserting" OnDataBinding="ListViewDataBinding" InsertItemPosition="LastItem" runat="server" ItemPlaceholderID="itemPlaceHolder">
...
...
Any Idea how to solve this?
Stéphane
After looooong investigations and rebuilding of the page control by control, the reason was that the viewstate was compressed and the scriptmanager didnt like it somehow, even though I specify the hidden field to it.
Probleme solved...
I have a page with a table of stuff and I need to allow the user to select rows to process. I've figured out how to add a column of check boxes to the table but I can't seem to figure out how to test if they are checked when the form is submitted. If they were static elements, I'd be able to just check do this.theCheckBox but they are programaticly generated.
Also I'm not very happy with how I'm attaching my data to them (by stuffing it in there ID property).
I'm not sure if it's relevant but I'm looking at a bit of a catch-22 as I need to known which of the checkboxes that were created last time around were checked before I can re-run the code that created them.
Edit:
I've found an almost solution. By setting the AutoPostBack property and the CheckedChanged event:
checkbox.AutoPostBack = false;
checkbox.CheckedChanged += new EventHandler(checkbox_CheckedChanged);
I can get code to be called on a post back for any check box that has changed. However this has two problems:
The call back is processed after (or during, I'm not sure) Page_Load where I need to use this information
The call back is not called for check boxes that were checked when the page loaded and still are.
Edit 2:
What I ended up doing was tagging all my ID's with a know prefix and stuffing this at the top of Form_Load:
foreach (string v in this.Request.Form.AllKeys)
{
if (v.StartsWith(Prefix))
{
var data = v.Substring(Prefix.Length);
}
}
everything else seems to run to late.
I'm going to assume you're using a DataList but this should work with and Control that can be templated. I'm also going to assume you're using DataBinding.
Code Front:
<asp:DataList ID="List" OnItemDataBound="List_ItemDataBound" runat="server">
<ItemTemplate>
<asp:CheckBox ID="DeleteMe" runat="server"/>
<a href="<%# DataBinder.Eval(Container, "DataItem.Url")%>" target="_blank">
<%# DataBinder.Eval(Container, "DataItem.Title")%></a>
</ItemTemplate>
</asp:DataList>
<asp:Button ID="DeleteListItem" runat="server" OnClick="DeleteListItem_Click" ></asp:Button>
Code Behind:
public partial class Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
LoadList();
}
protected void DeleteListItem_Click(object sender, EventArgs e)
{
foreach (DataListItem li in List.Items)
{
CheckBox delMe = (CheckBox)li.FindControl("DeleteMe");
if (delMe != null && delMe.Checked)
//Do Something
}
}
LoadList();
}
protected void LoadList()
{
DataTable dt = //Something...
List.DataSource = dt;
List.DataBind();
}
protected void List_ItemDataBound(object sender, DataListItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)
{
string id = DataBinder.Eval(e.Item.DataItem, "ID").ToString();
CheckBox delMe = (CheckBox)e.Item.FindControl("DeleteMe");
if (delMe != null)
delMe.Attributes.Add("value", id);
}
}
}
First, make sure that each Checkbox has an ID and that it's got the 'runat="server"' in the tag.
then use the FindControl() function to find it.
For example, if you're looping through all rows in a GridView..
foreach(GridViewRow r in Gridview1.Rows)
{
object cb = r.FindControl("MyCheckBoxId");
if(r != null)
{
CheckBox chk = (CheckBox)cb;
bool IsChecked = chk.Checked;
}
}
Postback data is restored between the InitComplete event and the PreLoad event. If your checkboxes are not created until later then the checkboxes will play "catch up" with their events and the data will be loaded into the control shortly after it is created.
If this is to late for you then you will have to do something like what you are already doing. That is you will have to access the post data before it is given to the control.
If you can save the UniqueId of each CheckBox that you create then can directly access the post data without having to given them a special prefix. You could do this by creating a list of strings which you save the ids in as you generate them and then saving them in the view state. Of course that requires the view state to be enabled and takes up more space in the viewstate.
foreach (string uniqueId in UniqueIds)
{
bool data = Convert.ToBoolean(Request.Form[uniqueId]);
//...
}
Your post is a little vague. It would help to see how you're adding controls to the table. Is it an ASP:Table or a regular HTML table (presumably with a runat="server" attribute since you've successfully added items to it)?
If you intend to let the user make a bunch of selections, then hit a "Submit" button, whereupon you'll process each row based on which row is checked, then you should not be handling the CheckChanged event. Otherwise, as you've noticed, you'll be causing a postback each time and it won't process any of the other checkboxes. So when you create the CheckBox do not set the eventhandler so it doesn't cause a postback.
In your submit button's eventhandler you would loop through each table row, cell, then determine whether the cell's children control contained a checkbox.
I would suggest not using a table. From what you're describing perhaps a GridView or DataList is a better option.
EDIT: here's a simple example to demonstrate. You should be able to get this working in a new project to test out.
Markup
<form id="form1" runat="server">
<div>
<table id="tbl" runat="server"></table>
<asp:Button ID="btnSubmit" runat="server" Text="Submit"
onclick="btnSubmit_Click" />
</div>
</form>
Code-behind
protected void Page_Load(object sender, EventArgs e)
{
for (int i = 0; i < 10; i++)
{
var row = new HtmlTableRow();
var cell = new HtmlTableCell();
cell.InnerText = "Row: " + i.ToString();
row.Cells.Add(cell);
cell = new HtmlTableCell();
CheckBox chk = new CheckBox() { ID = "chk" + i.ToString() };
cell.Controls.Add(chk);
row.Cells.Add(cell);
tbl.Rows.Add(row);
}
}
protected void btnSubmit_Click(object sender, EventArgs e)
{
foreach (HtmlTableRow row in tbl.Rows)
{
foreach (HtmlTableCell cell in row.Cells)
{
foreach (Control c in cell.Controls)
{
if (c is CheckBox)
{
// do your processing here
CheckBox chk = c as CheckBox;
if (chk.Checked)
{
Response.Write(chk.ID + " was checked <br />");
}
}
}
}
}
}
What about using the CheckBoxList control? I have no Visual Studio open now, but as far as I remember it is a DataBound control, providing DataSource and DataBind() where you can provide a list at runtime. When the page does a postback you can traverse the list by calling something like myCheckBoxList.Items and check whether the current item is selected by calling ListItem.Selected method. This should work.
Add them in an override of the CreateChildControls method of the Page. Be sure to give them an ID! This way they get added to the control tree at the correct time.
IMHO The best way would be to use DataBound Templated Control though, i.e. something like a ListView (in .NET 3.5). then in pageload after postback traverse all items in the databound control and use item.FindControl to get at the actual checkbox.
What I ended up doing was tagging all my ID's with a know prefix and stuffing this at the top of Form_Load:
foreach (string v in this.Request.Form.AllKeys)
{
if (v.StartsWith(Prefix))
{
var data = v.Substring(Prefix.Length);
}
}
everything else seems to run to late.