元素綁定

數(shù)據(jù)綁定最簡單的形式是，源對象是WPF元素而且源屬性是依賴屬性。依賴項屬性具有內(nèi)置的更改通知支持，當在源對象中改變依賴項屬性的值時，會立即更新目標對相中的綁定屬性。

<!--Xaml程序 -->
<Grid>
    <StackPanel>
        <Button x:Name="btn"  Margin="20" Click="btn_Click" Width="40"  Height="35"/>
        <TextBox  Text="{BindingElementName=txt2,Path=Text,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"/>
        <!-- TextBox綁定屬性名為txt2，綁定其Text，雙向綁定，屬性改變時更新 -->
        <TextBlock x:Name="txt2" />
    </StackPanel>
</Grid>

//后臺程序

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void btn_Click(object sender, RoutedEventArgs e)
    {
        txt2.Text += "k";
    }
}

BindingMode枚舉值

UpdateSourceTrigger

數(shù)據(jù)綁定

<!-- Xaml程序 -->
<Grid>
    <StackPanel>
        <DataGrid ItemsSource="{Binding PerList}" IsReadOnly="True"></DataGrid>
        <ComboBox x:Name="com" ItemsSource="{Binding PerList}" DisplayMemberPath="Name" Margin="10" Width="80" Height="30"/>
        <!--綁定PerList，展示其Name屬性 -->
    </StackPanel>
</Grid>

//后臺程序
public partial class MainWindow : Window
{
    public List<string> LT { get; set; }
    List<Person> Perss { get; set; }

    public MainWindow()
    {
        PersonList perlist = new PersonList();  //創(chuàng)建一個PersonList對象
        Perss = new List<Person>() { new Person("Getsu1","男"), new Person("Getsu2", "男"), new Person("Getsu3", "男")};
        perlist.PerList = Perss; //給PerList屬性賦值
        this.DataContext = perlist; //將perlist加入上下文,設置之后綁定才會有效
    }
}

public class PersonList
{
    public List<Person> PerList { get; set; }
    public PersonList()
    {
        PerList = new List<Person>();
    }
    public class Person
    {
        private string _name;
        private string _sex;
        public string Name
        {
            get { return _name; }
            set{ _name = value; }
        }       
        public string Sex
        {
            get { return _sex; }
            set{ _sex = value; }
        }
        public Person(string name, string sex)
        {
            Name = name;
            Sex = sex;
        }
    }
}

INotifyPropertyChanged

屬性更改通知接口。向客戶端發(fā)出某一屬性已更改的通知。
event PropertyChangedEventHandler PropertyChanged;
PropertyChanged 在屬性改變時發(fā)生。

<!-- X -->
 <StackPanel>
    <TextBox Text="{Binding Name,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"></TextBox>
    <TextBox Text="{Binding Sex,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"></TextBox>

    <TextBlock Text="{Binding Name,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"/>
    <!-- 不會隨著TextBox內(nèi)容的改變而改變-->
    <TextBlock Text="{Binding Sex,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"/>
    <!-- 會隨著TextBox內(nèi)容的改變而改變-->
</StackPanel>

//后臺程序
public partial class MainWindow : Window
{
    public MainWindow()
    {
        Person per = new Person("kakarot", "Male");
        this.DataContext = per;
        InitializeComponent();
    }
}

public class Person : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    private string _name;
    private string _sex;

    public string Name
    {
        get { return _name; }
        set
        {
            _name = value;
            //NotifyPropertyChanged("Name");
        }
    }

    public string Sex
    {
        get { return _sex; }
        set
        {
            _sex = value;
            NotifyPropertyChanged("Sex");
        }
    }
    private void NotifyPropertyChanged(String info)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }
    public Person(string name, string sex)
    {
        Name = name;
        Sex = sex;
    }
}

特性

public string Sex
{
    get { return _sex; }
    set
    {
        _sex = value;
        NotifyPropertyChanged();
        //使用特性之后可以自動獲取屬性名
    }
}
                                    //特性的表示
private void NotifyPropertyChanged([CallerMemberName]String info="默認值")
{
    if (PropertyChanged != null)
    {
        PropertyChanged(this, new PropertyChangedEventArgs(info));
    }
}