I have created a simple web form on ASP.NET which includes a DropDownList with the names of all the records of a table (h. PhotoAlbums) in my database. When the user selects an album, all the items of this album (photos with tootlips) appear on the page in an order. I have carried out this by the aid of ListView control assigning a LINQ source as data source.
I would like by the selection of an album to grant the user the possibility to insert new items in the selected album at the same time and on the same page besides the appearance of the already existed items in the album. I think that I should merely use a DetailsView control and adjust this, so as to insert items. Is it though possible the DetailsView to appear after the selection of an album; not when the page is loaded initially? How?
If I understand your question,
You can Initially set the visible = "false" to the DetailsView. Then in your DropDownList OnSelectedIndexChanged method you can check the selected value and set the visible= "true". In your DropDownList you should set the property AutoPostBack="true"
Hope This Helps
Related
If I have 2 entities that share a navigation property (In my case an entity called Groups and one called Requirements) and I have a Gridview that displays Groups and another Gridview that I want to display the Requirements in the navigation property of the selected Group, should I pull in all the Requirements in the Requirements DataSource and then filter in the Gridview or should I filter in the DataSource?
I tried filtering in the Requirements DataSource by doing some Linq in the OnQueryCreated event, but I realized that OnQueryCreated is called when the page is loaded and then not again. Is there another event I should use?
Basically: Should I filter in the DataSource and if so where? If I should filter somewhere else, where?
I have an update panel that includes a dropdownlist control and a detailsview control. The dropdownlist is populated by a sqldatasource control which grabs the data from a table called Places (just a list of venues). The detailsview is insert mode only and inserts places into the database table that populates the dropdownlist. I am trying to allow someone to insert a new place inside the update panel and have the dropdownlist refreshed at the same time so the user will see all places in the dropdownlist, including the one they just added with the details view. Right now, the detailsview is adding the place to the database properly but not updating the dropdownlist. If I refresh the page after adding a new place, the droplist updates with the new place. Any suggestions?
Disclaimer: This answer was posted before any code was posted in the question.
This also assumes both controls are inside the update panel.
In the event handler for Updating or Inserting for your DetailsView control, you need to add the following code:
MyDropDownList.DataBind()
And, worst case scenario, you can do this if the update panel is causing you problems. It's not the greatest performance-wise though.
Response.Redirect(Request.RawURL)
Lets say I have three DropDownList controls in a web user control and they depend on each other.
Categories
Brands
Products
Explanation:
After I choose a category from Categories dropdown list, related brands are loaded in Brands DropDownList and same happens when I choose specific brand and they are all located in a web user control since I am using it too much on different pages, I don't want to copy and paste the same code on all the pages.
Problem: The pages can contain a GridView and DataSource control which needs an additional Where parameter to fetch all the data needed in and that parameter could depend on selected product within the Products DropDownList control.
Question: So how can I get that Selected Product Value from Products DropDownList to bind it to SQLDataSource or any other DataSource control.
My Thoughts: I belive I can solve this problem in the ways following.
I can use static variable which is updated once Products selected. That field variable could be public so everyone can reach it
Selected Products DropDownList can create a QueryString Field for me to grap the selected value.
In the same way, the dropdownlist can create a Session variable on the fly and I can fetch the value
It can create a hidden field maybe.
But: Well those are some of my thoughts but I found them so naive to implement. I need something elegant and satisfying to solve this problem. It should be something like a gateway from the Web User Control to outside world.
Maybe a separate class or a Property can help me in the gateway solution.
Anyways, I am waiting for your answers.
If I'm understanding the question correctly:
You can add a property to the user control that exposes the products DDL selected value.
You can also add and raise an event from the user control that fires when the products DDL selected value changes. Creating a custom event argument that contains the product value, allows it to get passed directly to the event handler.
Then your pages can handle the event raised by the user control, have the product value, and bind the grid.
You could bind the DropDownList.SelectedIndexChanged events to the same function, and test the SelectedValue properties of each DropDownList. If their SelectedValues are valid, bind the grid to your DataSource.
I've done this in the past when I needed users to input a certain amount of data before I could query the database. I set the Hidden property on my GridView if the DropDownLists weren't valid, and reset it when they were properly bound.
I have a two text boxes named region id and region name..and a button control
I enter some values into those text boxes and click the button to insert those values into the "gridview"and a "data table" associated with the gridview.
The gridview has the "enable editing" set to true..but when i click the "edit" button of a particular row in a gridview i get no response...i.e i do not get editable textboxes as it happens normally...
What is the solution for this?
You need to set the EditIndex of the row you are editting on the gdvMyGridView_RowEditing event:
gdvMyGridView.EditIndex = e.NewEditIndex
This will display your EditItemTemplate for the relevant row.
GridView Examples for ASP.NET 2.0: Editing the Underlying Data in a GridView
Editable GridView in ASP.NET 2.0
Edit control does not work out of blue. You have to write a backend SQL query for it to implement. The query will most likely look like this.
update regions SET name=#name where ID=#ID
where name and ID are fields of the table. Make sure the ID is the primary key, otherwise update will not work and you won't get any error.
I have a database with 2 records Id and Description.
What I want to do is try to bind this to a table so for example
<tr>
<drop down select list with ids available> <textbox>
</tr> <add button>
So the user can select an id from the drop down list, enter a description then click an add button next to this which will duplicate that block dynamically so they can enter as many as they like. What is the best way to go about this in webforms? Detailsview? I'm not sure how to make it dynamically add html blocks though? Any help would be appreciated.
pseudocode :
foreach description
create new tablerow
create a table cell in the row with the description as a label
create a table cell in the row with the id dropdown as a combobox
add the tablerow to the table.rows collection
the tricky part is accessing the data in your dynamically created table, but it shouldn't be hard to do as long as you set an identifier on each control that can be tied back to your data.
I'd stay away from any of the built in controls (i.e. DetailsView, FormView) for anything other than simple CRUD forms, as it's not much more effort to manually create your own data-entry forms.
Dynamically adding controls to an ASP.NET Webform (and have them work across postbacks) is quite a tricky one to get right, but in short you'll need to do something like:
Add a table server control which will store your dynamic rows.
Create a property (stored in ViewState or ControlState) to store a count of rows available.
Handle the appropriate 'add' button click event, to increment the count property and add a new table row, and child controls.
Inside an OnInit event, create the number of table rows stored in the count property.
Dynamically created controls aren't persisted across postbacks, so you'll need to create them on every postback during the pages OnInit method. As long as the controls are recreated in the right order and with the same ID's, then they will be repopulated successfully on postback.
Because you're dynamically adding controls, you may need to set the pages EnableEventValidation property to false.