如何：向墨迹数据添加自定义数据

2008-08-18

更新：2007 年 11 月

您可以向墨迹添加自定义数据，在将墨迹另存为墨迹序列化格式 (ISF) 时将保存自定义数据。您可以将自定义数据保存到 DrawingAttributes、StrokeCollection 或 Stroke 中。由于能够在三个对象上保存自定义数据，因此，您可以决定保存数据的最佳位置。所有这三个类均使用类似的方法来存储和访问自定义数据。

只有以下类型的数据可以另存为自定义数据：

示例

下面的示例演示如何添加和检索 StrokeCollection 中的自定义数据。

Private timestamp As New Guid("12345678-9012-3456-7890-123456789012")


' Add a timestamp to the StrokeCollection.
Private Sub AddTimestamp() 

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

End Sub 'AddTimestamp


' Get the timestamp of the StrokeCollection.
Private Sub GetTimestamp() 

    If inkCanvas1.Strokes.ContainsPropertyData(timestamp) Then
        Dim [date] As Object = inkCanvas1.Strokes.GetPropertyData(timestamp)

        If TypeOf [date] Is DateTime Then
            MessageBox.Show("This StrokeCollection's timestamp is " + CType([date], DateTime).ToString())
        End If
    Else
        MessageBox.Show("The StrokeCollection does not have a timestamp.")
    End If

End Sub 'GetTimestamp

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.");
    }
}

下面的示例创建了一个显示 InkCanvas 和两个按钮的应用程序。 switchAuthor 按钮使两个不同的作者能够各用一枝笔。 changePenColors 按钮可以按作者来更改 InkCanvas 上每个笔画的颜色。此应用程序定义了两个 DrawingAttributes 对象，并向每个对象添加了一个自定义属性以指明是哪个作者绘制了 Stroke。当用户单击 changePenColors 时，应用程序将按照自定义属性的值来更改笔画的外观。

<Window x:Class="Window1"
    xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="https://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>

Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Data
Imports System.Windows.Documents
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Imports System.Windows.Shapes
Imports System.Windows.Ink


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

Partial Class Window1
    Inherits Window '

    Private authorGuid As New Guid("12345678-9012-3456-7890-123456789012")
    Private teachersDA As New DrawingAttributes()
    Private studentsDA As New DrawingAttributes()
    Private teacher As String = "teacher"
    Private student As String = "student"
    Private useStudentPen As Boolean = False


    Public Sub New()
        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

    End Sub 'New


    ' Switch between using the 'pen' DrawingAttributes and the 
    ' 'highlighter' DrawingAttributes.
    Private Sub switchAuthor_click(ByVal sender As [Object], ByVal e As RoutedEventArgs)
        useStudentPen = Not useStudentPen

        If useStudentPen Then
            switchAuthor.Content = "Use teacher's pen"
            inkCanvas1.DefaultDrawingAttributes = studentsDA
        Else
            switchAuthor.Content = "Use student's pen"
            inkCanvas1.DefaultDrawingAttributes = teachersDA
        End If

    End Sub 'switchAuthor_click


    ' Change the color of the ink that on the InkCanvas that used the pen.
    Private Sub changeColor_click(ByVal sender As [Object], ByVal e As RoutedEventArgs)
        Dim s As Stroke
        For Each s In inkCanvas1.Strokes
            If s.DrawingAttributes.ContainsPropertyData(authorGuid) Then
                Dim data As Object = s.DrawingAttributes.GetPropertyData(authorGuid)

                If TypeOf data Is String AndAlso CStr(data) = teacher Then
                    s.DrawingAttributes.Color = Colors.Black
                End If
                If TypeOf data Is String AndAlso CStr(data) = student Then
                    s.DrawingAttributes.Color = Colors.Green
                End If
            End If
        Next s

    End Sub 'changeColor_click
End Class 'Window1

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;
                }
            }
        }
    }
}

通过

如何：向墨迹数据添加自定义数据

示例

其他资源