WPF: 2011

Getting Started:

Creating WPF Project.

Open Visual Studio 2010.
Go to File => New => Project
Select Windows in installed templates
Select WPF Application
Enter the Name and choose the location.
Click OK

First of all add a new class using add new item tab and rename that class name.

MyFriends.cs

using System;using System.Windows;using System.ComponentModel;using System.Collections.Generic;using System.Linq;using System.Text;using System.Windows.Controls;using System.Windows.Data;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Imaging;using System.Windows.Navigation;using System.Windows.Shapes;

class MyFriends : INotifyPropertyChanged{ // INotifyPropertyChanged Members public event PropertyChangedEventHandler PropertyChanged; protected void Notify(string propName) { if (this.PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propName)); } } string name; public string Name { get { return this.name; } set { if (this.name == value) { return; } this.name = value; Notify("Name"); } } int age; public int Age { get { return this.age; } set { if(this.age == value ) { return; } this.age = value; Notify("Age"); } } string country; public string Country { get { return this.country; } set { if (this.country == value) { return; } this.country = value; Notify("Country"); } } string profession; public string Profession { get { return this.profession; } set { if (this.profession == value) { return; } this.profession = value; Notify("Profession"); } } string mobileNo; public string MobileNo { get { return this.mobileNo; } set { if (this.mobileNo == value) { return; } this.mobileNo = value; Notify("MobileNo"); } } string favQuote; public string FavQuote { get { return this.favQuote; } set { if (this.favQuote == value) { return; } this.favQuote = value; Notify("FavQuote"); } } public MyFriends() { } public MyFriends(string name, int age, string country, string profession, string mobileNo, string favQuote) { this.name = name; this.age = age; this.country = country; this.profession = profession; this.mobileNo = mobileNo; this.favQuote = favQuote; }} class Friends : List<MyFriends> { }

I am adding three more classes:

[ValueConversion(/*sourceType*/ typeof(int), /*targetType*/ typeof(Brush))] public class AgeToForegroundConverter : IValueConverter { // Called when converting the Age to a Foreground brush public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { // Only convert to brushes... if (targetType != typeof(Brush)) { return null; } // DANGER! After 25, it's all downhill... int age = int.Parse(value.ToString()); return (age > 25 ? Brushes.Red : Brushes.Black); } public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { // Should not be called in our example throw new NotImplementedException(); } }

public class Base16Converter : IValueConverter{ public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { // Convert to base 16 return ((int)value).ToString("x"); } public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { // Convert from base 16 return int.Parse((string)value, System.Globalization.NumberStyles.HexNumber); }}public class NumberRangeRule : ValidationRule{ int min; public int Min { get { return min; } set { min = value; } } int max; public int Max { get { return max; } set { max = value; } } public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo) { int number; if (!int.TryParse((string)value, out number)) { return new ValidationResult( false, "Invalid number format"); } if (number < min || number > max) { return new ValidationResult( false, string.Format("Number out of range ({0}-{1})", min, max)); } //return new ValidationResult(true, null); // valid result return ValidationResult.ValidResult; // static valid result // to save on garbage }}

Window.xaml.

<class:Base16Converter x:Key="ageConverter"></class:Base16Converter>  </Window.Resources>   <Grid DataContext="{StaticResource MyGoodFriends}" Width="386">
  <TextBlock Margin="12,24,331,320">Name:</TextBlock>
  <TextBox Text="{Binding Path=Name}" Margin="86,24,12,307" IsReadOnly="True" />
  <TextBox  Foreground="{Binding Path=Age, Converter={StaticResource ageConverter}}" Margin="86,69,11,265" x:Name="txtAge">
  <TextBox.Text>
  <Binding Path="Age" UpdateSourceTrigger="PropertyChanged" NotifyOnValidationError="True">
  <Binding.ValidationRules>
  <class:NumberRangeRule Min="0" Max="100"></class:NumberRangeRule>
  </Binding.ValidationRules>
  </Binding>        </TextBox.Text>
  </TextBox>
  <Button Margin="86,319,54,12" x:Name="btnBirthday" Click="btnBirthday_Click">When is my Birthday</Button>
  <TextBlock Margin="12,69,0,274" HorizontalAlignment="Left" Width="34">Age:</TextBlock>
  <Button Content="Back" Margin="272,292,0,48" Click="btnBack_Click" x:Name="btnBack" HorizontalAlignment="Left" Width="47" />
  <Button Content="Next" Margin="0,292,13,48" x:Name="btnForward" Click="btnForward_Click" HorizontalAlignment="Right" Width="48" />
  <TextBlock HorizontalAlignment="Left" Margin="12,113,0,226" Width="54">Country:</TextBlock>
  <TextBlock HorizontalAlignment="Left" Margin="13,0,0,189" Width="63" Height="22" VerticalAlignment="Bottom">Profession:</TextBlock>
  <TextBox IsReadOnly="True" Margin="87,105,11,226" Text="{Binding Path=Country}" />
  <TextBox IsReadOnly="True" Margin="87,147,11,189" Text="{Binding Path=Profession}" />
  <TextBlock Height="22" HorizontalAlignment="Left" Margin="13,0,0,159" VerticalAlignment="Bottom" Width="63">Mobile No.:</TextBlock>
  <TextBox IsReadOnly="True" Margin="87,182,12,154" Text="{Binding Path=MobileNo}" />
  <TextBlock Height="22" HorizontalAlignment="Left" Margin="12,0,0,124" VerticalAlignment="Bottom" Width="63">Fav Quote:</TextBlock>
  <TextBox IsReadOnly="True" Margin="86,215,13,82" Text="{Binding Path=FavQuote}" />
  </Grid></Window>

.xaml.cs

public partial class BindListData : Window{ public BindListData() { InitializeComponent(); Validation.AddErrorHandler(this.txtAge, txtAge_ValidationError); } ICollectionView GetFriendsView() { Friends people = (Friends)this.FindResource("MyGoodFriends"); return CollectionViewSource.GetDefaultView(people); }

Figure 1.

private void btnBirthday_Click(object sender, RoutedEventArgs e) { // Get the current person out of the collection view
ICollectionView view = GetFriendsView(); MyFriends person = (MyFriends)view.CurrentItem; ++person.Age; MessageBox.Show(string.Format("Happy Birthday {0}, on your {1}th Birthday ", person.Name, person.Age)); }

Figure 2.

private void btnForward_Click(object sender, RoutedEventArgs e){ ICollectionView view = GetFriendsView(); view.MoveCurrentToNext(); if (view.IsCurrentAfterLast) { view.MoveCurrentToLast(); }}

Figure 3.
private void btnBack_Click(object sender, RoutedEventArgs e){ ICollectionView view = GetFriendsView(); view.MoveCurrentToPrevious(); if (view.IsCurrentBeforeFirst)
{ view.MoveCurrentToFirst(); }}

Figure 4.

void txtAge_ValidationError(object sender, ValidationErrorEventArgs e){   // Show the string created in NumberRangeRule.Validate
  //txtAge.ToolTip = (string)e.Error.ErrorContent;
  // Show the string pulled out of the exception by the
  // ExceptionValidationRule
  MessageBox.Show((string)e.Error.ErrorContent, "Validation Error");}

Figure 5.

namespace System.Windows.Data{   public enum UpdateSourceTrigger   {   Default = 0, // updates "naturally" based on the target control
  PropertyChanged = 1, // updates the source immediately
  LostFocus = 2, // updates the source when focus changes
  Explicit = 3, // must call BindingExpression.UpdateSource()
  }}

If you

<class:AgeToForegroundConverter x:Key="ageConverter" />

Figure 6.

Figure 7.

WPF

Wednesday, 3 August 2011

Custom Data Binding, Data Navigation and Data Validation in WPF