1.1绑定到对象
1.1.1、前台绑定
前台代码
5: </Grid>
1: <Grid x:Name=”GridProductDetails”>
2:
3: <TextBox Grid.Column="1" x:Name="txtModelNum" Text="{ Binding Path=ModelNumber}"/>
4:
对应后台代码
1: Model_Product BP = new BLL_Product().GetProduct(123);
2: GridProductDetails.DataContext = BP;
1.1.2、后台绑定
前台代码
1: <Grid x:Name=”GridProductDetails”>
2: <TextBox Grid.Column="1" x:Name="txtModelNum" />
3: </Grid>
对应后台代码
1: Binding B = new Binding();
2: B.Source=BP;
3: B.Path = new PropertyPath("ModelNumber");
4: txtModelNum.SetBinding(TextBox.TextProperty, B);
1.2 绑定到控件
有一列表框控件ListBox绑定到一个List<Product> 数据源，显示项为Product对象的ModelName属性，前台代码如下
1: <ListBox Name="lstProducts" Margin="5" DisplayMemberPath="ModelName"
2: SelectionChanged="lstProducts_SelectionChanged">
3: </ListBox>
对应后台代码为
1: private ICollection<Product> products;
2: products = App.StoreDb.GetProducts();
3: lstProducts.ItemsSource = products;
现在将一个Grid里面的一系列控件绑定到ListBox所选择的数据项上，用于构建“主--详细信息”的显示结构，代码如下
1: <Grid DataContext="{Binding ElementName=lstProducts, Path=SelectedItem}" TextBox.TextChanged="txt_TextChanged">
2: <TextBox Margin="5" Text="{Binding Path=ModelNumber}"></TextBox>
3: </Grid>
1.3 绑定的双向更新
1.3.1 对象和控件的双向更新
双向更新：即修改对象的属性值后，对应的前台控件自动更新为修改后的值。
前台无需做任何修改，只需在对象类Model定义的时候实现INotifyPropertyChanged接口即可：
1: public class Model_Product : INotifyPropertyChanged
2: {
3: string modelNumber;
4:
5: public string ModelNumber
6: {
7: get { return modelNumber; }
8: set
9: {
10: modelNumber = value;
11: OnPropertyChanged(new PropertyChangedEventArgs("ModelNumber"));
12: }
13: }
14:
15: int _ID;
16: public int ID
17: {
18: get { return _ID; }
19: set { _ID = value; }
20: }
21: /// <summary>
22: /// 实现INotifyPropertyChanged接口 可以实现控件值和对象属性值的自动绑定 当修改对象值后 控件的值自动刷新
23: /// </summary>
24: public event PropertyChangedEventHandler PropertyChanged;
25: public void OnPropertyChanged(PropertyChangedEventArgs e)
26: {
27: if (PropertyChanged != null)
28: PropertyChanged(this, e);
29: }
30: }
31:
1.3.2 绑定到对象集合(类似于List<T>)的双向更新
双向更新：即修改对象的属性值后，对应的前台控件自动更新为修改后的值
。
无需些多少代码，只需把数据集合申明为实现了INotifyPropertyChanged接口的集合类型就可以了，在WPF中这个常用的有ObservableCollection<T>这个泛型集合类，如果是WindosForm编程，有个BindingList集合(实现了IBingdingList接口)
1: public ICollection<Product> GetProducts()
2: {
3: DataSet ds = StoreDbDataSet.ReadDataSet();
4:
5: ObservableCollection<Product> products = new ObservableCollection<Product>();
6: foreach (DataRow productRow in ds.Tables["Products"].Rows)
7: {
8: products.Add(new Product((string)productRow["ModelNumber"],
9: (string)productRow["ModelName"], (decimal)productRow["UnitCost"],
10: (string)productRow["Description"], (int)productRow["CategoryID"],
11: (string)productRow["CategoryName"], (string)productRow["ProductImage"]));
12: }
13: return products;
14: }
1.4 绑定到ADO.NET数据集 DataSet
Controls.ItemsSource=DateSetObject.Tables[n].DefaultView;
需要注明Controls的DisplayMemberPath属性
删除数据集行建议采取的方法
((DataRowView)lstProducts.SelectedItem).Row.Delete();
1.5 绑定到LINQ集合
1: public ICollection<Product> GetProductsFilteredWithLinq(decimal minimumCost)
2: {
3: // Get the full list of products.
4: ICollection<Product> products = GetProducts();
5:
6: // Create a second collection with matching products.
7: IEnumerable<Product> matches = from product in products
8: where product.UnitCost >= minimumCost
9: select product;
10:
11: return new ObservableCollection<Product>(matches.ToList());
12: }
此处采用public ObservableCollection(List<T> list)实现对LINQ结果集的转换以实现双向更新：即修改对象的属性值后，对应的前台控件自动更新为修改后的值。
1.6 绑定验证
前台代码：
1: <Window x:Class="WPFGameTest.DataBinding.TestOfValidationRules"
2: xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
3: xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
4: Title="TestOfValidationRules" Height="300" Width="300">
5: <StackPanel >
6:
7: <TextBox x:Name="textBox1" Margin="5" />
8:
9: <Slider x:Name="slider1" Minimum="-10" Maximum="110" Margin="5" />
10:
11:
12: </StackPanel>
13:
14: </Window>
后台代码
1: using System;
2: using System.Collections.Generic;
3: using System.Linq;
4: using System.Text;
5: using System.Threading.Tasks;
6: using System.Windows;
7: using System.Windows.Controls;
8: using System.Windows.Data;
9: using System.Windows.Documents;
10: using System.Windows.Input;
11: using System.Windows.Media;
12: using System.Windows.Media.Imaging;
13: using System.Windows.Shapes;
14:
15: namespace WPFGameTest.DataBinding
16: {
17: /// <summary>
18: /// TestOfValidationRules.xaml 的交互逻辑
19: /// </summary>
20: public partial class TestOfValidationRules : Window
21: {
22: public TestOfValidationRules()
23: {
24: InitializeComponent();
25:
26: Binding binding = new Binding("Value")
27: {
28: Source = this.slider1
29: };
30:
31: binding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
32:
33: RangeValidateRule rvr = new RangeValidateRule();
34: rvr.ValidatesOnTargetUpdated = true;
35: binding.ValidationRules.Add(rvr);
36:
37: binding.NotifyOnValidationError = true;
38: this.textBox1.SetBinding(TextBox.TextProperty, binding);
39:
this.textBox1.AddHandler(Validation.ErrorEvent,new RoutedEventHandler(this.ValidationError));
40:
41: }
42: void ValidationError(object sender, RoutedEventArgs e)
43: {
44: Control C = sender as Control;
45:
46: if (Validation.GetErrors(C).Count > 0)
47: {
48: (C).Background = new SolidColorBrush(Colors.Red);
49: C.ToolTip = Validation.GetErrors(C)[0].ErrorContent.ToString();
50: }
51: else
52: {
53: (C).Background = new SolidColorBrush(Colors.White);
54: C.ToolTip = null;
55: }
56:
57: }
58:
59: }
60: public class RangeValidateRule:ValidationRule
61: {
62: public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
63: {
64: double d = 0;
65: if (double.TryParse(value.ToString(),out d))
66: {
67: if(d >= 0 && d <= 100)
68: {
69: return new ValidationResult(true,null);
70: }
71: }
72:
73: return new ValidationResult(false,"Validation Failed !!!");
74: }
75: }
76:
77: }
要点在第39行，为一个附加事件，关于附加事件可以参考http://msdn.microsoft.com/zh-cn/library/ms598899(v=VS.95).aspx
另外还有个衍生知识要点是“扩展方法”，这两个应该属于高级一点的编程特性，扩展方法请参照http://msdn.microsoft.com/zh-cn/library/vstudio/bb383977.aspx
1.6.1 注意e.Action == ValidationErrorEventAction.Removed
注意：在值一改变就验证的模式中，不可以用下面的代码方式来处理验证信息。因为当发生一个验证错误时，此时的xe.Action 值为 ValidationErrorEventAction.Added， 代码执行到第10行后跳出ValidationError方法。
此时系统会认为错误验证已经被处理，就会自动再次执行ValidationError，而此时的xe.Action 值为 ValidationErrorEventAction.Removed。
所以使用此方法用于验证，会出现看不到红色背景的效果。
MSDN是这样解释的：
如果发生验证错误，绑定引擎将引发 BindingValidationError 事件。 ValidationError 传递到包含一个新 Exception 的事件处理程序，且 Action 值为 Added。
如果该验证错误得到解决（极有可能是用户通过使用验证信息对项进行更新来解决的），则相同的 ValidationError 将传递到包含原始异常的事件处理程序，且 Action 值为 Removed。
次验证方法适合于有提交按钮的情况，当点击提交按钮后执行下面的验证。
1: void ValidationError(object sender, RoutedEventArgs e)
2: {
3: Control C = sender as Control;
4: ValidationErrorEventArgs xe = e as ValidationErrorEventArgs;
5: if (xe.Action == ValidationErrorEventAction.Added )
6: {
7: if (Validation.GetErrors(C).Count > 0)
8: {
9: (C).Background = new SolidColorBrush(Colors.Red);
10: C.ToolTip = Validation.GetErrors(C)[0].ErrorContent.ToString();
11: }
12: }
13: if (xe.Action == ValidationErrorEventAction.Removed)
14: {
15: (C).Background = new SolidColorBrush(Colors.White);
16: }
17:
18: }
1.6.2 使用绑定组来验证
1: GridProductDetails.DataContext = BP;
2: BindingGroup bin = new System.Windows.Data.BindingGroup();
3: bin.Name = "bb";
4: GridProductDetails.BindingGroup = bin;
5: GridProductDetails.BindingGroup.BeginEdit();
6:
7:
8: PositivePriceRule rule = new PositivePriceRule();
9: rule.Max = 300;
10:
11:
12: Binding B = new Binding();
13: B.Source = BP;
14: B.Path = new PropertyPath("ID");//
15: B.NotifyOnValidationError = true;
16: B.ValidatesOnExceptions = true;
17: B.Mode = BindingMode.TwoWay;
18: B.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
19: B.ValidationRules.Add(rule);
20:
B.BindingGroupName = bin.Name;
21:
22: txtModelNum.AddHandler(Validation.ErrorEvent, new RoutedEventHandler(this.ValidationError));
23: txtModelNum.SetBinding(TextBox.TextProperty, B);
关键的代码在第20行，通过指定Binding对象的BindingGroupName 属性来关联Binding对象到BindingGroup组里面。
此番修改以后，如果出现错误，使用BindingGroup的控件(第4行GridProductDetails.BindingGroup = bin)的边框就会变为红色。