学习WPF之 Binding

1.Binding数据的校验

public _02Binding_ValidationRules()
{
InitializeComponent();
Binding binding = new Binding("Value") { Source = slider1, UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged };

RangeValidationRule rvr = new RangeValidationRule();
rvr.ValidatesOnTargetUpdated = true;
binding.ValidationRules.Add(rvr);
binding.NotifyOnValidationError = true;

textBox1.SetBinding(TextBox.TextProperty, binding);

this.textBox1.AddHandler(Validation.ErrorEvent, new RoutedEventHandler(ValidationError));
//this.slider1.AddHandler(Validation.ErrorEvent, new RoutedEventHandler(ValidationError2));
}

void ValidationError(Object sender, RoutedEventArgs e)
{
if (Validation.GetErrors(this.textBox1).Count > 0)
{ textBox1.ToolTip = Validation.GetErrors(this.textBox1)[0].ErrorContent.ToString(); }
}

public class RangeValidationRule : ValidationRule
{
public override ValidationResult Validate(object value, CultureInfo cultureInfo)
{
double d;
if (double.TryParse(value.ToString(), out d))
{
if (d >= 0 && d <= 100)
{
return new ValidationResult(true, null);
}
}

return new ValidationResult(false, "验证失败!");
}
}

2.Binding的数据转换

C#
/// <summary>
/// 种类
/// </summary>
public enum Category
{
Bomber,
Fighter
}

/// <summary>
/// 状态
/// </summary>
public enum State
{
Available,
Locked,
Unknown
}

/// <summary>
/// 飞机类
/// </summary>
public class Plane
{
public string Name { get; set; }

public Category Category { get; set; }

public State State { get; set; }

}

C# 窗体.cs

/// <summary>
/// 给ListBox的ItemsSource属性赋值
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void buttonLoad_Click(object sender, RoutedEventArgs e)
{
ObservableCollection<Plane> planeList = new ObservableCollection<Plane>()
{
new Plane(){Category=Category.Bomber,Name="B-1",State=State.Unknown},
new Plane(){Category=Category.Bomber,Name="B-2",State=State.Unknown},
new Plane(){Category=Category.Fighter,Name="F-22",State=State.Unknown},
new Plane(){Category=Category.Fighter,Name="Su-47",State=State.Unknown},
new Plane(){Category=Category.Bomber,Name="B-52",State=State.Unknown},
new Plane(){Category=Category.Fighter,Name="J-10",State=State.Unknown},
};

this.listBoxPlane.ItemsSource=planeList;

}

private void buttonSave_Click(object sender, RoutedEventArgs e)
{
StringBuilder sb = new StringBuilder();
foreach (Plane  p in listBoxPlane.Items)
{
sb.AppendLine(string.Format("Category={0},Name={1},State={2}",p.Category,p.Name,p.State));
}
File.WriteAllText(@"D:\PlaneList.txt",sb.ToString());
MessageBox.Show("OK");
}

public class CategoryToSourceConverter : IValueConverter
{
//将Category转换为Uri
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
Category c = (Category)value;
switch (c)
{
case Category.Bomber:
return @"Icons\Bomber.png";

case Category.Fighter:
return @"Icons\Fighter.png";

default:
return null;
}
}

public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}

public class StateToNullabelBoolConverter : IValueConverter
{

/// <summary>
///将State转换为Bool
/// </summary>
/// <param name="value"></param>
/// <param name="targetType"></param>
/// <param name="parameter"></param>
/// <param name="culture"></param>
/// <returns></returns>
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
State s = (State)value;
switch (s)
{
case State.Available:
return true;
case State.Locked:
return false;
case State.Unknown:
default:
return null;
}
}

/// <summary>
/// 将Bool转换为State
/// </summary>
/// <param name="value"></param>
/// <param name="targetType"></param>
/// <param name="parameter"></param>
/// <param name="culture"></param>
/// <returns></returns>
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
bool? nb = (bool?)value;
switch (nb)
{
case true:
return  State.Available;
case false:
return  State.Locked;
case null:
default:
return  State.Unknown;

}
}
}

Xaml

<Window.Resources>
<local:CategoryToSourceConverter x:Key="cts"/>
<local:StateToNullabelBoolConverter x:Key="stnb"/>
</Window.Resources>

<StackPanel Background="LightBlue">
<ListBox x:Name="listBoxPlane" Height="160" Margin="5">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<Image Width="20" Height="20" Source="{Binding Path=Category,Converter={StaticResource cts}}"/>
<TextBlock Text="{Binding Path=Name}" Width=" 60" Margin="8,0"/>
<CheckBox IsThreeState="true" IsChecked="{Binding Path=State,Converter={StaticResource stnb}}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>

<Button x:Name="buttonLoad" Content="Load" Height="25" Margin="5" Click="buttonLoad_Click"/>

<Button x:Name="buttonSave" Content="Save" Height="25" Margin="5,5" Click="buttonSave_Click"/>

</StackPanel>

3.MultiBinding(多路Binding)

C#
namespace MyTestWPFApplication._2015年9月16日

{
/// <summary>
/// _04MultiBinding.xaml 的交互逻辑
/// </summary>
public partial class _04MultiBinding : Window
{
public _04MultiBinding()
{
InitializeComponent();
SetMultiBinding();
}

void SetMultiBinding()
{
Binding b1 = new Binding("Text") { Source = textBox1 };
Binding b2 = new Binding("Text") { Source = textBox2 };
Binding b3 = new Binding("Text") { Source = textBox3 };
Binding b4 = new Binding("Text") { Source = textBox4 };

MultiBinding mb = new MultiBinding() { Mode = BindingMode.OneWay };
mb.Bindings.Add(b1);
mb.Bindings.Add(b2);
mb.Bindings.Add(b3);
mb.Bindings.Add(b4);

mb.Converter = new LogonMultiBindingConverter();
button1.SetBinding(Button.IsEnabledProperty, mb);
}
}

//因为这里的Converter类是是用来给MultiBinding的Converter来指定的.所以继承的接口不再是IValueConverter而是IMultiValueConverter
class LogonMultiBindingConverter : IMultiValueConverter
{

public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{

if (!values.Cast<string>().Any(text => string.IsNullOrEmpty(text))
&& values[0].ToString() == values[1].ToString()
&& values[2].ToString() == values[3].ToString())
{
return true;
}
return false;
}

public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}
}

XAML
<StackPanel Background="LightBlue">
<TextBox x:Name="textBox1" Height="23" Margin="5,25,5,5" Width="140"/>
<TextBox x:Name="textBox2" Height="23" Margin="5" Width="140"/>
<TextBox x:Name="textBox3" Height="23" Margin="5" Width="140"/>
<TextBox x:Name="textBox4" Height="23" Margin="5" Width="140"/>
<Button x:Name="button1" Content="Submit" Width="80" Margin="5"></Button>
</StackPanel>

Binding学完了!