Session 4 From Access Forms to Windows Forms.NET Adam Cogan Database Architect ssw.com.au

About Adam Chief Architect for - experience with: –internal corporate development and –generic off-the-shelf databases –Clients: Enterasys Networks, Cisco, Microsoft… Run Teams of Developers President.NET User Group, Sydney Speaker for Microsoft Roadshows, Dev Conn, VSLive Microsoft Regional Director, Australia New World

To From

Overview Access 97 to Access 2003 Accessto SQL Server AccesstoReportingServices AccesstoWindows Forms.NET 1234

Agenda Current Problems What’s New in.NET Lab: Migrating from Access Forms to Windows Forms.NET Breezers Drink Receipt From Outback OzOutback Oz

Assumptions Backend in SQL Server 2000 Using Enterprise Manager for data management Access forms front-end Reports using Reporting Services Some VBA knowledge

Session Prerequisites (Current Problems) 1. 1.“Our application stopped working on Mary’s machine when we installed the new version of Office” 2. 2.“Our Access database got corrupted and we can’t open it” 3. 3.“Our Access forms run too slowly - we want a small, fast EXE” 4. 4.“Can we stop the continual polling of SQL Server so we can scale this application?” 5. 5.“We want to integrate with other systems”

Enter.NET No need for Access runtime or Office for end-user (1) Produce an EXE which doesn’t get corrupted like an MDB (2) The EXE is small and runs fast (3) Only explicit updates to database (4) Web Service Support are built in (use an open XML-based architecture) (5)

Problems with Bound Access Forms Advantage – Database Connections are Controllable In Access Forms perform database queries in the background Cannot be controlled In.NET Full control over database connections and queries Improved performance and scalability Not as smooth a ridesmooth a ride

Problems with Bound Access Forms Advantage – Database Connections are Controllable In Access In.NET

Differences In Form Design Advantage – A Shallow Learning Curve for Access Developers (1 of 2)

Differences In Form Design Advantage – A Shallow Learning Curve for Access Developers (2 of 2)

Northwind.NET

Differences In Form Design New Feature – Anchoring Controls

Differences In Form Design New Feature – Docking Controls

Differences In Form Design Advantage – Powerful New Controls (1 of 2)

Differences In Form Design Advantage – Powerful New Controls (2 of 2)

Data Forms In Access 1.Get Data – Make Queries

Data Forms In Access 2.Bind – Set the One RecordSource

Data Forms In Access 3.Bind – Set the ControlSource for all bound controls

Data Forms In.NET 1.Get Data – Create Data Components (DataSets and DataAdapters)

Data Forms In.NET 2.Bind – Set the Many Referenced DataSets

Data Forms In.NET 3.Bind – Set the DataBindings for all bound controls

Differences In Form Design Disadvantage – Database Updates Are Not Done Automatically In Access 1.Changes made on forms are automatically saved In.NET: 1.Add a save button 2.Call DataAdapter.Update(DataSet) in the OnClick event

Differences in Application Design Advantage – All.NET Solution Items are Described in Plain Text In Access Everything is in the MDB If damaged, everything stops working In.NET All solution items are in plain text Forms described in XML Low chance of corruption Lightweight

Differences In Form Design Difference – Data Views AccessVisual Studio.NET DesignSupported FormCompile and Run Application DatasheetNot supported

Navigation Private Sub previousRecord_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles previousRecord.Click ' Check that the user isn't on the first record. If Not Me._ordersManager.Position = 0 Then _movingRecords = True Me._ordersManager.Position -= 1 _movingRecords = False End If End Sub Private Sub nextRecord_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles nextRecord.Click ' Check that the user isn't on the last record. If Not Me._ordersManager.Position = Me._ordersManager.Count - 1 Then _movingRecords = True Me._ordersManager.Position += 1 _movingRecords = False End If End Sub

Add / Edit Line Items Private Sub editItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles editItem.Click ' Check that there is a row to edit. If Not BindingContext(ordersList, "Orders.OrdersOrder_Details").Position = -1 Then Dim cm As CurrencyManager = CType(BindingContext(ordersList, "Orders.OrdersOrder_Details"), CurrencyManager) ' Get the current row. Dim orderItem As OrdersDataSet.Order_DetailsRow = CType(CType(cm.Current, DataRowView).Row, OrdersDataSet.Order_DetailsRow) ' Pass the current row to the Order Details form. Dim orderDetailsForm As New OrderDetailsPopupForm(orderItem) ' Show the Order Details form and return the result. Dim result As DialogResult = orderDetailsForm.ShowDialog() ' Check if the user clicked "OK". If result = DialogResult.OK Then CalculateTotals() End If End Sub

Save Data Private Sub btnOK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOK.Click Me._ordersManager.EndCurrentEdit() ' Check if changes were made If ordersList.HasChanges Then ' Update the Orders table _ordersDA.Adapter.Update(ordersList) ' Update the Order Details table _orderDetailsDA.Adapter.Update(ordersList) End If End Sub

Differences In Form Design Disadvantage – Multiple Columns Not Supported in Some Controls Use.NET ListView instead of Access Listbox Some programming required for multi-column ComboBox

Differences In Form Design Disadvantage – Multiple Columns Not Supported in Some Controls

Differences In Form Design Disadvantage – The Datasheet View Is Harder to Implement In Access View – Datasheet In.NET: Use DataGrid control Manually bind to database Hard to implement advanced controls (ComboBox etc.)

Differences In Form Design Disadvantage – Continuous Forms Are Harder to Implement (1 of 4) In Access Form Property: Default View = Continuous Forms In.NET Not supported in.NET 2 options –Tiled user controls –Summary/Detail

Differences In Form Design Disadvantage – Continuous Forms Are Harder to Implement (2 of 4) Tiled user controls

Differences In Form Design Disadvantage – Continuous Forms Are Harder to Implement (3 of 4) Split into summary/detail for complex subforms

Differences In Form Design Disadvantage – Continuous Forms Are Harder to Implement (4 of 4) Split into summary with popup window

Differences In Form Design Disadvantage – Subforms are Easier to Use than User Controls (1 of 2) In Access 1.Create parent and sub forms 2.Add subform/subreport to parent 3.Set linkages between parent/subform

Differences In Form Design Disadvantage – Subforms are Easier to Use than User Controls (2 of 2) In.NET 1.Create Orders form (parent) 2.Create user control for Orders Subform form 3.Add property to user control to link parent and subform (code) 4.Update the Orders Subform (user control) when the parent record changes (code) 5.Add the Orders Subform (user control) to the Orders form 6.Bind the Orders form to the Orders Subform (user control) Note: We take a different approach with our example (popup window)

Differences In Form Design Advantage – Form Inheritance 1.Add any common form controls and logic into a base form 2.Create new instances of (“inherit”) the parent form to ensure consistency 3.Make any required changes to logic and controls on child forms

Differences In Form Design Advantage – Use Windows XP Styles Easy to implement in.NET

Differences In Form Design Disadvantage – Read-Only Textboxes are Grayed Out In Access Set Locked = Yes In.NET Set ReadOnly = True Have to explicitly set the background colour

Differences In Form Design Disadvantage – Combo Boxes Cannot Be Locked In Access Set Locked = Yes In.NET No automatic way Capture the SelectedIndexChanged event and reset the value

Differences In Form Design Advantage – Applications Are Stored As Binary Executables In Access Use compact and repair Manually compile as MDE In.NET Application automatically compiled on run Runs efficiently because it is in binary

Differences in Application Design Advantage – Application Deployment is Easier In Access: License for Office Developer Edition (for runtime), or Office installed on target machine In.NET you only need the free.NET Framework

Differences in Application Design Advantage –.NET Versions Can Be Run Side-by-Side In Access: Upgrading Office can cause issues (as we have seen) Can have multiple versions of Office installed – however MDB associations don’t know enough In.NET: Framework versions can run side-by-side Apps using 1.0 continue to work alongside 1.1

Advantage – Extending Your Forms to Mobile Devices Differences in Application Design

Difference – Security Model Integrates with Windows In Access Maintain two sets of security for forms (Access) and backend (SQL)

Differences in Application Design Difference – Security Model Integrates with Windows In.NET Use Windows Integrated security Based on Active Directory – one model for forms and SQL Server Check user’s role in code (using System.Security.Principal namespace)

Differences in Application Design Disadvantage – No Wizard-Based Security In Access: Use the User-level Security Wizard to automatically set object permissions In.NET: Form permissions must be defined in code

Differences in Programming Difference – VBA replaced by VB.NET In Access you use VBA.DLLs In.NET VB.NET, C#, J# etc. Can use components written in other languages

Differences in Programming Advantage – Improved Language Features Structured exception handling Form and code inheritance XML and XSL functionality for web services Simple API wrappers – less API calls –accessing printers –file dialog boxes Improved internationalisation and regional customisation Create and deploy DLLs, user controls and web services in.NET

Differences in Programming Difference – Macros replaced by VB.NET In Access you use the visual macro designer In.NET you must rewrite as code Tip: Use the Macro to VBA converter to simplify rewriting

Differences in Programming Difference – Responding to Form Events.NET – new “Handles” keyword One method can handle multiple events All Access form events can be handled Private Sub OpenCustomer (…) Handles btnOK.Click, cboCustomers.DoubleClick … End Sub

Differences in Programming Advantage – Improved Development Environment (1 of 3) Improved Intellisense

Differences in Programming Advantage – Improved Development Environment (2 of 3) Improved design-time debugging

Differences in Programming Advantage – Improved Development Environment (3 of 3) Visually build database objects

Differences in Programming Advantage – Use Unit Testing Tools to Check Your Code Cannot test code in Access.NET supports testing frameworks eg. nUnit

Differences in Programming Difference – Autoexec Macros vs. Startup Forms/Stubs In Access: –Startup form –Autoexec Macro In.NET: –Select form in project properties –Shared Sub Main()

Summary Current Problems –New versions of Office cause applications to stop working –Corrupt Access databases –Slow, large Access forms –Continual automatic polling of SQL Server, limiting scalability –Hard to integrate with other systems What’s New in.NET Lab: Migrating Access forms to.NET

For More Information… Microsoft Access: Upgrading and Migrating to SQL Server and.NET - Course Resources More courses in March – see Tell your friends…

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