I have a textbox inside a gridview.
It was initially set to Disable state.
I am enabling and disabling it in javascript.
But the problem arises during the postbacks.The grid view was able to persist the textbox data but not the Enable/Disable values.During every postback it comes back disabled even when it is enabled before the postback.
I have explored around the use of hidden field to maintain the state in these scenarious but I wish there is something less tiresome...
Can some one enlighten me on this issue...
Seeing the code could really help but generally take off the Enable="False" from the HTML then in the Page_Load event add something like:
Protected void Page_Load(Object Sender, EventArgs e)
{
if (!IsPostBack)
{
tetxBox.enabled = false;
}
}
Related
I have a bunch of GridView on one page, and each have their own coordinating SqlDataSource.
They all load their coordinating data when initializing the page (on the page load). I want to Load the data for specific SqlDataSource(s) on the page when the user clicks a button, so that it is not trying to load ALL the data for all the different grids all at the same time when the page initially loads.
Note: I need to also have Paging working, and anything I have tried so far has broken the paging functionality.
Looking to tell the SqlDataSource what data to bind to it after the user clicks a button, and then have the specific GridView Bind that data to it and have the Paging functionality work with the data it was told to load.
Environment: C#, WebForms, ASP.NET, .NET 3.5, Controls SqlDataSource / GridView
From what I can tell it correctly binds the data, but the 'gridview' control keeps disappearing when I click one of the pages at the bottom for the paging.
Note: If I click the button again, it will show the correct page and the correct data for the page.
protected void btn_LoadData2_Click(object sender, EventArgs e) { Gridview2.DataSourceID = "DataSource2"; Gridview2.SelectCommand = "SELECT * FROM dbo.DataNeeded"; Gridview2.DataBind(); Gridview2.DataBind(); }
Add a Selecting event to each of your data sources. Then in the code behind check if IsPostBack and if IsPostBack is false then cancel the operation.
protected void MyDataSource_Selecting(object sender, SqlDataSourceSelectingEventArgs e)
{
if (!IsPostBack)
e.Cancel = true;
}
I have a problem with listbox. I would like to fill it with data and select Value (listbox.SelctedValue), using postback, after textbox is filled and Page.Validate() is fired. I try to use it in Page_Load. Everything works fine until I dont mark another user. It goes back to the the first one. I know its because I mark the first one again and again it in Page_Load, but how can I mark user after postback in other place? I cant use any buttons.
To be more clear, I have one text box, which causes postback after user put text there. After that I would like to check if Page.Isvalid and is yes, add that user to listbox (which also causes postbacks) and mark him. Without any buttons. How can I do it only once, using autopostback, not every PageLoad ?
Try this
protected void Page_Load(object sender, EventArgs e)
{
if (Page.IsPostBack)
{
if (Page.IsValid)
{
//Mylistbox.SelctedValue = set Your Selected Value
}
}
}
I have this button event:
protected void AddDetails_Click(object sender, EventArgs e)
{
DataSetTableAdapters.SelectFriendsTableAdapter sft = new DataSetTableAdapters.SelectFriendsTableAdapter();
try
{
sft.AddFriend(current, newFriend, false);
}
catch
{
error.Text = "Something happened. Bummer!";
}
}
in the try section, I'm adding entries in the Database. In the page there are Labels / Textboxes with the corresponding values.
Everything works fine. However, I need to refresh the page in order to see the changes after I click on this submit button.
I have added if(!IsPostBack) at the beginning of the PageLoad code, but I still need to visit another page / come back to see the changes.
Any ideas?
Thanks.
Thank you for your replies. I'm using a ListView:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DataSetTableAdapters.SelectFriendsTableAdapter sdt = new DataSetTableAdapters.SelectFriendsTableAdapter();
DataTable tab = sdt.SelectFriends();
ListView1.DataSource = tab;
ListView1.DataBind();
}
}
, so the ListView content should get updated.
If you don't want to refresh the page and you're using asp.net webforms you can use an UpdatePanel and place all your controls inside of it, etc... That will keep the changes made in the form / display when you submit the info. I'm assuming the form is on submitting the changed/new data as you didn't specifically state how the data was being updated/changed.
If you don't want to use an update panel, then when the page is posting back you will have to set the values for the UI controls that you want to update with the values from the 'newFriend' object (I'm assuming that has the changed values).
Found it!
The solution for this issue is to add this code at the end of your submit button click event:
Server.Transfer("currentpage.aspx");
Here is what I am trying to do in two simple steps:
1) New Row (trNewPost) which has table inside and controls in it to add new post or to update existing post.
Default Visible=false;
2) Add Button to make above row visible = true;
3) trMyPosts has Gridview in it and displays all the posts.
Default visible = true.
When user click on editing any row of the gridview (RowCommand event) I just want to hide this grid (trMyPosts) and show trNewPost.
That's all. events firing, but nothing happening.
I think you've got viewstate problem.
One of the things you can do is this :
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
// do things here
}
}
Because whenever anything happens, the page posts back. By encapsulating your Page_Load with ! Page.IsPostBack, you prevent those things from happening over and over again.
Now, if your variable is a global variable, you will have this same problem. Consider instead using a Session variable.
Also, I just wanted to show you this piece of code just in case :
protected void HideShowClicked(object sender, EventArgs e)
{
// toggle the visibility of the control
// (that is, if visible then hide, if hidden then show)
myControl.Visible = ! myControl.Visible;
}
I understand the order the events occur with page life cycle but it is not helping with my situation. I have a checkboxlist that is populated by a directory filled with forms. When I check a box next to the name of the form I would like it to dynamically create a wizard step and insert the form.
Order of events:
OnInit:
GatherForms() - Checks directory and loads all form names into checkbox
LoadForms() - Checks "Selected" Session and loads forms that were collected
CheckBoxList:SelectedIndexChanged #AutoPost = true#
PopulateForms() - Loops through the checkboxs and adds them to session state
When the user clicks the checkbox it does a postback and hits the OnInit which pulls from the session. The problem is that PopulateForms() was not ran yet so it populated nothing even though it is checked. If I click another item it will postback and appear. I cannot seem to be able to pull any kind of useful information from the checkbox before the refresh which means I cannot see the forms appear immediately. I have also tried looping the checkbox but unfortunately viewstate hasnt posted yet. sigh.
Any suggestions?
Thanks!
P.S: I cannot use Request.Form[] because I have to get all the selected items out of the checkbox. maybe i can but i cannot find a way :/
This is a common problem I wrestle with as I get better at ASP.NET.
With dynamic controls you have the problem of them not actually existing during OnInit.
What you can do is create all of the controls the user may see during OnInit, and hide the elements the user won't see in code. The page will load, all possible controls will be instantiated (in code - don't worry this appearing in your HTML and bloating it), then the event handler will fire, and then you can deal with setting the visibility of your wizard.
For example:
public void OnInit(object sender, EventArgs e)
{
GatherForms();
CreateWizardForm(); // creates a wizard and adds controls it will need
}
private void Checkbox_Checked(object sender, EventArgs e)
{
var checkBox = (CheckBox)sender;
// append checkBox.SelectedValue to session state object of checkboxes
}
protected override void OnPreRender(object sender, EventArgs e)
{
if (/* Session checkboxes contain values */)
{
this.WizardForm.Visible = true;
this.CheckboxList.Visible = false;
}
}
This works provided you know ahead of time which controls will be in the wizard form. You can change the values of those controls in the OnPreRender event, toggle their visibility, etc, but you can't go and add new controls (e.g. Controls.Add(new Button())) - that has to be done in the OnInit event.
Only add your dynamic controls in OnInit. Don't do any population/processing until PageLoad. You will retain your values this way.
A classic pitfall with dynamic controls.
Honestly the best solution is to just wield the Request values array to look for the information you need and ignore the lifecycle stuff for this particular situation.
In OnInit(), the posted values are there, they just haven't been dealt with by ViewState yet. So you can just do if (Request["myCheckBoxName"] == xxx) to deal with individual checkboxes, or if you can use Request["__EVENTTARGET"] to get the name of the control that caused the postback.
See my old answer here for a more thorough discussion of the issue.