通过

如何：将自定义数据添加到墨迹数据

您可以将自定义数据添加到墨迹中，这些数据将在墨迹保存为墨迹序列化格式（ISF）时一并保存。 可以将自定义数据保存到 DrawingAttributes、StrokeCollection 或 Stroke中。 能够在三个对象上保存自定义数据，让你能够决定保存数据的最佳位置。 这三个类都使用类似的方法来存储和访问自定义数据。

只能将以下类型保存为自定义数据：

示例：

以下示例演示如何添加和检索自定义数据从 StrokeCollection。

Guid timestamp = new Guid("12345678-9012-3456-7890-123456789012");

// Add a timestamp to the StrokeCollection.
private void AddTimestamp()
{

    inkCanvas1.Strokes.AddPropertyData(timestamp, DateTime.Now);
}

// Get the timestamp of the StrokeCollection.
private void GetTimestamp()
{

    if (inkCanvas1.Strokes.ContainsPropertyData(timestamp))
    {
        object date = inkCanvas1.Strokes.GetPropertyData(timestamp);

        if (date is DateTime)
        {
            MessageBox.Show("This StrokeCollection's timestamp is " +
                ((DateTime)date).ToString());
        }
    }
    else
    {
        MessageBox.Show(
            "The StrokeCollection does not have a timestamp.");
    }
}

以下示例创建一个应用程序，显示一个 InkCanvas 和两个按钮。 该按钮 switchAuthor允许两个不同的作者使用两支笔。 该按钮 changePenColors 会根据作者更改每个笔划 InkCanvas 的颜色。 应用程序定义DrawingAttributes对象，并给每个对象添加一个自定义属性，以指示作者绘制的Stroke。 当用户单击 changePenColors时，应用程序会根据自定义属性的值更改笔划的外观。

<Window x:Class="Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Adding Custom Data to Ink" Height="500" Width="700"
    >
  <DockPanel Name="root">

    <StackPanel  Background="DarkSlateBlue">
      <Button Name="switchAuthor" Click="switchAuthor_click" >
        Switch to student's pen 
      </Button>
      <Button Name="changePenColors" Click="changeColor_click" >
        Change the color of the pen ink
      </Button>
    </StackPanel>
    <InkCanvas Name="inkCanvas1">
    </InkCanvas>
  </DockPanel>
</Window>

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.Windows.Ink;

/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>

public partial class Window1 : Window
{
    Guid authorGuid = new Guid("12345678-9012-3456-7890-123456789012");
    DrawingAttributes teachersDA = new DrawingAttributes();
    DrawingAttributes studentsDA = new DrawingAttributes();
    string teacher = "teacher";
    string student = "student";
    bool useStudentPen = false;

    public Window1()
    {
        InitializeComponent();

        teachersDA.Color = Colors.Red;
        teachersDA.Width = 5;
        teachersDA.Height = 5;
        teachersDA.AddPropertyData(authorGuid, teacher);

        studentsDA.Color = Colors.Blue;
        studentsDA.Width = 5;
        studentsDA.Height = 5;
        studentsDA.AddPropertyData(authorGuid, student);

        inkCanvas1.DefaultDrawingAttributes = teachersDA;
    }

    // Switch between using the 'pen' DrawingAttributes and the
    // 'highlighter' DrawingAttributes.
    void switchAuthor_click(Object sender, RoutedEventArgs e)
    {
        useStudentPen = !useStudentPen;

        if (useStudentPen)
        {
            switchAuthor.Content = "Use teacher's pen";
            inkCanvas1.DefaultDrawingAttributes = studentsDA;
        }
        else
        {
            switchAuthor.Content = "Use student's pen";
            inkCanvas1.DefaultDrawingAttributes = teachersDA;
        }
    }

    // Change the color of the ink that on the InkCanvas that used the pen.
    void changeColor_click(Object sender, RoutedEventArgs e)
    {
        foreach (Stroke s in inkCanvas1.Strokes)
        {
            if (s.DrawingAttributes.ContainsPropertyData(authorGuid))
            {
                object data = s.DrawingAttributes.GetPropertyData(authorGuid);

                if ((data is string) && ((string)data == teacher))
                {
                    s.DrawingAttributes.Color = Colors.Black;
                }
                if ((data is string) && ((string)data == student))
                {
                    s.DrawingAttributes.Color = Colors.Green;
                }
            }
        }
    }
}