Can anyone please tel me an example for how to bind the data with the Collections and Lists. I know how to bind the data with databound controls. But, binding with the collection and Lists sounds little bit tougher.
Thanks.
Regards,
Naren.
You can use Collection.Add or Collection.AddRange where Collection can be any of collection like ArrayList in your case to add your data to the collection.
There is no binding involved here.
Binding is done in between data and controls.
Collections are used for collecting the data and no binding is involved.
Related
I have an Stored Procedure which may return some unpredictable rows and columns, based on some business logic written in my SP. That is for sure that it will return only one set of Result Set data from this SP.
Whatever the result my SP returns, it should be reflected into my GridView. Due to some framework restrictions, I can not use ADO.Net DataSets/DataTables.
I am using Entity Framework 4.0 for my project and I want some solution to bind my GridView with dynamic nature of DataSource returned by my Stored procedure.
I think, this is very common problem which many developer has encountered in such type of situation.
Is there anyone who have found some work around to achieve the goal within the boundary line of Entity Framework?
Note: Keep in mind that, I don't want to use ADO.net DataSet or DataTable.
I think you are fetching data from proc and stored in List like that.
List<HRDocumentCheckList> searchJoiningDoc = GetJoiningDocumentForEdit(ddlCategory.SelectedValue.ToInt32(), false).ToList();
gvJoiningDocumentTemplate.DataSource = searchJoiningDoc;
gvJoiningDocumentTemplate.DataBind();
Just bind the gridview and set the autogenrated column is false
Hope it will helps you
How to keep custom paging for dynamic result sets ? (i.e) based on 10 Dropdowns selection my stored procedure will Dynamically generates resultset,but it populates million records.
Row statically know Record count,cusom paging is efficient,but how to achieve it for dynamically grown result set?
Problem
I have to bind generic List to GridView,Columns are fixed,but the number of rows retuened are unknown,but without custom paging my GridView took 30 minutes to populate the result.
If possible, you should use LINQ, as the extensible operations make for easy paging.
Essentially, you would specify an ObjectDataSource or LinqDataSource for your GridView.
You would then have an IQueryable<T> method which accepts a starting position and number of rows to retrieve.
Then you make use of Skip() and Take() to achieve simple paging.
Here's a very good article on doing that.
Remember that Skip() and Take() are methods exposed to any class which implements IEnumerable. So even though the above article uses LINQ-SQL for their data repository, as long as your own DAL exposes a collection of type IEnumerable, you can use the Skip and Take pattern.
Hope that helps.
An easy way to do this server side would be to use LINQ. Took at the .Take() method.
Often I need to combine data from multiple tables and display the result in a GridView control.
I can write a Linq query inline in the Page_load event, return an anonymous type that combines all the fields that I need, and databind the result to the GridView control.
Problem: I use 'helper methods' as described by Scott Guthrie on his blog. Such a helper method cannot return an anonymous type. The query would have to be inline for this approach.
I can write a database view that returns the data that I need, and write a helper method with a query against this (new and known) type that it returns.
Problem: I will need a lot of views in my database schema, and I will introduce a lot of redundant aspects of my data. I also lose some of the advantage of using Linq - removing all business logic from the database.
I would like to take an approach that lets me keep the Linq queries in helper methods, yet allows me to access all the attributes that I need on the grid in their respective databinding expressions. Can this be done?
I asked the wrong question, as I frequently do. What prompted me to look into anonymous types was an apparent limitation of the GridView - my inability to use a databinding expression in an <asp:BoundField> (the DataField parameter only accepts column names of the table that the Linq query pulls in).
Turns out that in a TemplateField it is possible to use Eval and access members of the Linq data item, and Linq takes care of the query for me.
In other words, I can keep the query in my helper method, have it return a primary database table type (e.g. Account), and I bind the Accounts to the GridView.
In the databinding expressions I can access data members of the Account objects that reside in other tables, without having to explicitly pull them in in the query. Perfect.
I don't know if there is a viable way to achieve this using anonymous types. But I have a suggestion that will work in WinForms, but I am not sure about ASP.NET.
What you need is a type with properties where neither the number of properties, nor the types and names of the properties are known at compile time. One way to create such a thing is ICustomTypeDescriptor.
You have to create a type implementing this interface with an private backing store of objects backing the properties returned by the query for one row from the query. Then you implement GetProperties() to return one PropertyDescriptor per column and PropertyDescriptor.GetValue() and PropertyDescriptor.SetValue() to access the backing array.
By implementing PropertyDescriptor.Name you will get the correct column name; this will probably require another backing store storing the property names. And there is a lot more to implement, but in the end your new type will behave almost like a normal type - and now the if - if the control you are binding to knows about and uses ICustomTypeDescriptor.
UPDATE
I just found an bit of text stating that ASP.NET data binding knows and uses ICustomTypeDescriptor.
Scott's earlier post in the series talks about shaping the result set before inserting into a grid:
Part 3 - Querying our Database
Scroll down to "Shaping our Query Results".
I recently began working on a project which has many gridviews on a single page. During creation of a new record, the user needs to be able to add/remove/edit these gridviews and then save to the database at the end. The problem with this obviously is that there is no datasource to bind the data too until after its written to the database.
This data represents a 1..* relationship, which is why the gridview data cannot be written to the database until the parent record has been created first.
The best way I have found so far to solve this is to use viewstate. This solution however does not seem ideal to me. I am also forced to manually create the gridview functionality with OnDeleting, OnUpdating, etc so that I can manage the binding of the viewstate with the gridview.
Does anyone have any suggestions on a better way to manage this situation, it seems like it would be a common thing?
UPDATE:
Keep in mind this data needs to be around throughout postbacks.
Use a DataSet as an intermediate connection to your data source. Fill the DataSet with your data and then bind your GridView to the DataSet setting the GridView DataMember to the name of the table it is supposed to bind to.
As the user updates tables it will add/modify records in the DataTables in the DataSet. When the user is done editing and clicks "Save" your code can then update the database from the datasets, either automatically using a DataAdapter, or manually looking at the RowState of the rows in the DataTables.
Use a DataAdapter and a Dataset. Invoke the fillschema method in the adapter to create de metadata (cols, constraints, relations, etc) in the dataset. bind the data tables created to the different grid views. update manually cheking each row rowstate on each table or call the adapter's update method to do it automatically. If you do it automatically you need to define commands for insert, delete, and update in the adapter.
I need to convert a datagrid table in Adobe Flex to an ArrayCollection. I was expecting to be able to loop through each row of a datagrid and write that to the Array collection, but the only method for accessing data in the datagrid that I can find is SelectedItem, which doesn't help me.
Obviously one could just copy the dataProvider for the datagrid, but my datagrid is editable and I need to store the state of the datagrid at any one time into a database. Can anyone recommend a method of doing this?
Much Appreciated
-Matt
If your DataGrid is:
<mx:DataGrid id="someDG" dataProvider="{this.provider}" />
Then check if this.provider is Array or ArrayCollection. If it is ArrayCollection then access it simply by:
var gotIt:ArrayCollection = this.someDG.dataProvider as ArrayCollection;
if it is an Array, then:
var gotIt:ArrayCollection = new ArrayCollection(this.someDG.dataProvider as Array);
Hope this helps.
You can do it by iterating over the fields in the columns, but you should be using the data provider. If the only place the state of your data resides is in a transient user interface control then you have to get it back into the domain objects and serialise them. Presumably each row in the datagrid is an object of some sort, in which case I would re-cast your problem as how to keep the edits in the datagrid and the domain objects in sync. If you crack that then there's no need to iterate over the datagrid.
The easiest way to solve the sync problem is to watch events on your editing renderers in the datagrid. When the grid contents change you automatically update the domain object.
What are your in place editors in the grid?