学习WPF之 Binding

最近在学习WPF,通过看书,敲代码和做笔记等各种方式.昨天学习完了Binding这一章... ... 画了张图进行总结,以备遗忘时查看.

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

(效果图)

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");
        }
 

C# 转换类 需要IValueConverter接口

Convert函数为源到目标时调用

ConvertBack函数为目标到源时调用

   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!