An Array Data Grid with Sort and Filter Ability
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A custom data grid that gets an array object as its data source and can sort and filter it.
Introduction
System.Windows.Forms.DataGrid is a great control with so many features, but I think that it's a little bit hard to use it. So I wrote a user control that uses a data grid, but it's a little bit easier to use. Here are its features:
- It gets an array of objects as its data source
- It returns its selected item as an object
- It returns its selected items as an array of objects
- You can format it very easily
- You can add an object to its datasource
- You can remove an object from its datasource
- You can filter its datasource
- You can sort its datasource
How it works
Setting the datasource
You can set its datasource like this:
myGrid.DataSource=users; //users is an array of type User.
Formatting
You can format the grid using a GridFormatter object.
A grid formatter is an object that has some column formatter that will tell the grid how to format itself. Each column formatter contains a DataGridColumnStyle type.
GridFormatter format1=new GridFormatter() ;
format1.AddColumnFormatter("FirstName","FirstName",
typeof(DataGridTextBoxColumn));
If you want to hide a column, just don't add a column formatter to your grid formatter.
When the grid formatter is ready, we set our data grid formatter to let it format itself.
myGrid.GridFormatter=format1;
The good news is that you can change your formatter anytime you like.
GridFormatter uses a DataGridColumnStyle object to format the grid, you can easily show almost every thing in your grid. (Here is an article about DataGridColumnStyle by Declan Brennan that I found very interesting).Adding and removing records
There are times that you want to add or remove records at run time.
You can do it using the AddRow(object obj) and AddRows(object[] objects) methods.
myGrid.AddRow(new User("FName","LName"));
And if you want to remove some records, use Remove(object obj) or Remove(object[] objects).
Getting the selected items
You can get the current row (as an object) using the SelectedItem property.
User selectedUser=(User)myGrid.SelectedItem;
You can get the selected items (as an array of objects) using the SelectedItems property.
usersGrid.AddRows((User[])myGrid.SelectedItems);
Filtering and sorting
You can apply a filter to your grid using ApplyFilter(ExpressionBuilder expression). Applying the filter takes an Expression Builder to build its filter expression. An Expression Builder is an object that builds a string. For example, if you like to say "FirstName='Fname' And Age>'15'", you will write:
ExpressionBuilder expBuilder =
new AndExpression(new EqExpression("FirstName","FName"),
new GtExpression("Age",15));
It is very similar to the Hibernate/NHibernate expression object model.
There are different expression builders that work together using a Composite pattern, therefore you can combine them to make a complex expression.
Now we have an Expression Builder we can use to filter our grid.
myGrid.ApplyFilter(expBuilder);
To remove the filter, simply use the RemoveFilter() method.
If you want to sort a DataGrid, you can use an array of Order objects (again, it's very similar to Hibernate/NHibernate).
An order object takes a column name and a bool value indicating to sort ascending (true) or descending (false).
Order[] order=new Order[]{new Order("FirstName",true),
new Order("LastName",false)};
myGrid.Sort(order);
Final word
This is my first article at CodeProject. I hope you find it useful, and please let me know your opinion and comments.
Let me know what other features this grid should have.