1 / 44

Windows Forms

Windows Forms. A new plattform for Windows-based application development. Overview. Section 1: Introduction Section 2: Forms Section 3: Using Controls Section 4: Data bound Controls Section 5: User Controls Section 6: Miscellaneous Summary. Introduction. Basic concepts

tkeim
Download Presentation

Windows Forms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Windows Forms A new plattform for Windows-based application development

  2. Overview • Section 1: Introduction • Section 2: Forms • Section 3: Using Controls • Section 4: Data bound Controls • Section 5: User Controls • Section 6: Miscellaneous • Summary

  3. Introduction • Basic concepts • From Window to Control to Form • Delegates and Events • The Control class • Forms • Inheritance • Creating and using instances • The System.Drawing namespace

  4. Basic concepts • A window is the core component of Windows • Configured via attributes • SendMessage is the most important function • Not really object oriented • MFC as C++ oriented improvement • New library for the .NET framework • Windows Forms

  5. From Window to Control to Form • One common base class: Control • Represents a window • Offers properties and methods • The Form class is derived from Control • New Controls and Forms through Inheritance

  6. Delegates and Events • The control‘s way to send a message: an event • Delegates • Object oriented function pointers • The base of modern callback functions • Delegates are type safe • Events are based on delegates • Act as connection points • More than one handler possible Windows Forms: Overridable methods

  7. The Control Class • Implements basic functionality • Base class for predefined classes • Indirect base class for user controls • A lot of properties and methods • Color, position, size, child controls • Enhanced functionality • Docking, special message handling • No painting implemented

  8. Forms • Application windows • Different forms: standard, tool, dialog • Own forms through inheritance • Special attributes • DesktopLocation, AcceptButton, ShowDialog

  9. Inheritance • New window types through inheritance • Old methods: • API: WNDCLASS • VB: Form class or User Control (ActiveX) • .NET method • Inherited from (User)Control or Form • Really object oriented

  10. Creating and using Instances • Very familiar to Visual Basic programmers • Form • Create instance • Call the Show or ShowDialog method • Use properties and methods • Control • Create instance • Add to the containers Controls collection • Use properties and methods

  11. The System.Drawing namespace • Special data structures for position and so on • Defined in the System.Drawing namespace • Point for position • Rectangle and Size for dimensions • Color für Color values • Graphics encapsulate a Device Context • Drawing functions and elements

  12. Forms • GUI based applications • Forms • Forms and contained Controls • Dialogs • MDI applications

  13. GUI based applications • Use SYSTEM.WINDOWS.FORMS.DLL • Main function as entry point • Application class for message loop • The Run method opens the main form • User defined Form class for the main window • Override OnPaint for output • Override other event method for input handling

  14. Forms • New concepts • ClientSize instead of ScaleWidth, ScaleHeight • New names for known elements • Unload goes to Closing • New properties and functions • DesktopLocation, DesktopBounds

  15. Forms and contained Controls • Adding a control to a form • create the control instance • set the attributes of the control (Text, BackColor,…) • set the location and dimensions of the control • add event handlers for the control • add the control to the controls collection of the form

  16. Dialogs • Use ShowDialog to open a dialog • Returns a DialogResult value • How is the dialog closed • OK, Cancel, Yes, ... • AcceptButton, CancelButton properties • Extra OK and Cancel button handling • Return input values via • Public Controls • Public properties • Special dialog type: MessageBox

  17. MDI applications • Combination of Container and Child Form • IsMdiContainer property indicates the container • MdiParent property refers to the Container • Used by the Child Form • Other elements • ActiveMdiChild: active child form • MdiChildren: child forms array

  18. Using Controls • Layout • Buttons • Text Controls • List Controls • Menus • Common Dialogs • More controls

  19. Layout • Dynamic position of controls • Old: Calculate and move • New: Anchoring and Docking • Anchor • Fixed distance to borders • Dock • Connecting to an edge • Splitter

  20. Buttons • Abstract base class: ButtonBase • Button class for push buttons • DialogResult property • CheckBox • ThreeState, AutoCheck property • RadioButton • AutoCheck property

  21. Text Controls • Base class TextBoxBase • New functions • Lines property gets, sets a string array • Select method selects a range of text in the text box • AppendText method appends text • TextBox and RichTextBox are inherited classes • TextBox • Character casing, Password handling • RichTextBox • Supports RTF • DetectUrls, AutoWordSelection properties

  22. Simple List Controls • ListBox • Items are stored in an ObjectCollection • Additional collections for selected items • SelectedIndexCollection, SelectedObjectCollection • Enhanced and new functions • ComboBox • Combination of ListBox and TextBox • CheckedListBox • Owner Draw Mode

  23. Complex List Controls • ListView • (Multi column) list of items • Collections for Columns, Items and so on • More values as columns possible • TreeView • Hierarchical list of items • ImageList • Stores images for other controls

  24. Menus • Realized by a class hierarchy • Abstract base class Menu • MenuItem class for single items • MainMenu class for the forms main menu • ContextMenu class for shortcut menus • Useful events • Popup, MenuStart: context dependant states • Select: User feedback

  25. Toolbars • 2 classes: ToolBar + ToolBarButton • Buttons with different styles • Dropdown menus supported • Toggle buttons supported • ButtonClick + ButtonDropDown events • No events for status handling • Use the Application.Idle event instead

  26. Common Dialogs • OpenFileDialog, SaveFileDialog • Derived from FileDialog • Offers the OpenFile method • FontDialog • Raises an Apply event for preview functionality • ColorDialog • PageSetupDialog • PrintDialog

  27. More Controls • Tabbed views • TabControl and TabPage • StatusBar • Bar and Panels • Miscellaneous • PictureBox, LinkLabel, Timer, UpDown • TrackBar, Scrollbars, ProgressBar • MonthCalendar, DateTimePicker

  28. Data bound Controls • ADO.NET • Managed Providers • Using the OLE DB .NET Provider • Data Binding • Simple data binding • Complex data binding

  29. ADO.NET • New data access technology • Two core components • DataSet • .NET Managed Providers • DataSet contains other components • DataTable • DataRelation • Tight integration with XML

  30. Managed Providers • Data Source/Database access • Connection: Access to a data source • Command: SQL statements • DataAdapter • Bridge between DataSet and Database • OLE DB .NET Provider • Native OLE DB through COM Interop • SQL Client .NET Provider • SQL Server specific protocol

  31. Using the OLE DB .NET Provider • OleDbConnection • ADO like connection string • OleDbCommand • SQL statements: Select, Insert, Update • OleDbDataReader • Read only, forward only, fast • OleDbDataSet • Fill a DataSet

  32. Data Binding • Two types • Simple data binding • Label, TextBox, PictureBox • Complex data binding • DataGrid, ComboBox • Possible data sources • DataSet, DataTable, DataView, DataSetView • 1-dimensional Array, Collection

  33. Simple data binding • Binding a control to a data source • Binds one data field • Binds a property of the control • The Binding classes • Binding • BindingContext • BindingManagerBase • CurrencyManager

  34. Complex data binding • Bind more than one data field • Properties • DataSource • DataMember • Method • SetDataBinding • Updates by DataSet operations

  35. User Controls • Reusing existing controls • Extending standard controls • Composite controls • Custom Controls • Implemented from scratch • Design time support • Attributes • Type converter and editor, designer

  36. Reusing Existing Controls • Extending existing controls • Using standard controls as base class • Rich base functionality • Focus on new functions • Composite controls • Derived from UserControl • Combines standard controls • LabelTextbox: Label + TextBox

  37. Custom Controls • „Normal“ .NET Controls • Implementation is straightforward • Derived from System.Control • Sometimes from UserControl • Implemented from scratch • Overrides OnPaint for display • Special property support • ShouldSerialize, Reset

  38. Design time support (1) • Better cooperation with designers • Support for UDTs • Converter + editor • For properties and events • Based on attributes • Browsable: displayed in the property browser • Description: describes the property • DefaultValue: a simple default value • TypeConverter: a special converter

  39. Design time support (2) • Type converter • Converts from and to UDTs • UI Type Editor • Visual editing of UDTs • Type specific Dialogs • Custom Designer • Supports special design time demands

  40. Miscellaneous • ActiveX Controls • Special message handling • IMessageFilter interface • PreProcessMessage • Related classes • Keys • Cursors • System Information

  41. ActiveX Controls • Usable through wrappers • Aximp.exe generates control class • Creation via New statement • Usage like other controls • Special initialisation • BeginInit, EndInit • Main function requirers STAThread attribute

  42. Special Message Handling • IMessageFilter interface • Early message handling • 1 method: PreFilterMessage • Used by the Splitter control • PreProcessMessage • After PreFilterMessage, before any event • Some related functions • ProcessCmdKey, ProcessDialogKey • IsInputKey, IsInputChar

  43. Related classes • Keys • Cursors • SystemInformation

  44. Summary • Windows Form is • Straightforward • Really object oriented • Feature rich • Easy to use

More Related