StylusPoint.PressureFactor 属性

定义

命名空间:

System.Windows.Input

程序集:

PresentationCore.dll

获取或设置一个介于 0 和 1 之间的值，以反映在创建 StylusPoint 时，触笔施加于数字化仪图面的压力大小。

public:
 property float PressureFactor { float get(); void set(float value); };

public float PressureFactor { get; set; }

member this.PressureFactor : single with get, set

Public Property PressureFactor As Single

属性值

Single

介于 0 和 1 之间的值，用于指示在创建 StylusPoint 时，触笔施加于数字化仪图面的压力大小。

例外

ArgumentOutOfRangeException

将 PressureFactor 属性设置为一个小于 0 或大于 1 的值。

示例

以下示例使用 PressureFactor 属性检索并显示名为 points的 中StylusPointCollection每个 StylusPoint 的压力值。 此示例假定有一个名为 TextBlock 的 packetOutput。

private void WriteStylusPointValues(StylusPointCollection points)
{
    StylusPointDescription pointsDescription = points.Description;

    ReadOnlyCollection<StylusPointPropertyInfo> properties = 
        pointsDescription.GetStylusPointProperties();
    
    // Write the name and value of each property in
    // every stylus point.
    StringWriter packetWriter = new StringWriter();
    packetWriter.WriteLine("{0} stylus points", points.Count.ToString());
    foreach (StylusPoint stylusPoint in points)
    {
        packetWriter.WriteLine("Stylus Point info");
        packetWriter.WriteLine("X: {0}", stylusPoint.X.ToString());
        packetWriter.WriteLine("Y: {0}", stylusPoint.Y.ToString());
        packetWriter.WriteLine("Pressure: {0}", stylusPoint.PressureFactor.ToString());

        // Get the property name and value for each StylusPoint.
        // Note that this loop reports the X, Y, and pressure values differantly than 
        // getting their values above.
        for (int i = 0; i < pointsDescription.PropertyCount; ++i)
        {
            StylusPointProperty currentProperty = properties[i];

            // GetStylusPointPropertyName is defined below and returns the
            // name of the property.
            packetWriter.Write("{0}: ", GetStylusPointPropertyName(currentProperty));
            packetWriter.WriteLine(stylusPoint.GetPropertyValue(currentProperty).ToString());
        }
        packetWriter.WriteLine();
    }

    packetOutput.Text = packetWriter.ToString();
}

Private Sub WriteStylusPointValues(ByVal points As StylusPointCollection) 
    Dim pointsDescription As StylusPointDescription = points.Description
    
    Dim properties As ReadOnlyCollection(Of StylusPointPropertyInfo) = _
                            pointsDescription.GetStylusPointProperties()
    
    ' Write the name and value of each property in
    ' every stylus point.
    Dim packetWriter As New StringWriter()

    packetWriter.WriteLine("{0} stylus points", points.Count.ToString())

    For Each stylusPoint As StylusPoint In points

        packetWriter.WriteLine("Stylus Point info")
        packetWriter.WriteLine("X: {0}", stylusPoint.X.ToString())
        packetWriter.WriteLine("Y: {0}", stylusPoint.Y.ToString())
        packetWriter.WriteLine("Pressure: {0}", stylusPoint.PressureFactor.ToString())

        ' Get the property name and value for each StylusPoint.
        ' Note that this loop reports the X, Y, and pressure values differantly than 
        ' getting their values above.
        For i As Integer = 0 To pointsDescription.PropertyCount - 1

            Dim currentProperty As StylusPointProperty = properties(i)

            ' GetStylusPointPropertyName is defined below and returns the
            ' name of the property.
            packetWriter.Write("{0}: ", GetStylusPointPropertyName(currentProperty))
            packetWriter.WriteLine(stylusPoint.GetPropertyValue(currentProperty).ToString())
        Next i

        packetWriter.WriteLine()

    Next stylusPoint

    packetOutput.Text = packetWriter.ToString()

End Sub

// Use reflection to get the name of currentProperty.
private string GetStylusPointPropertyName(StylusPointProperty currentProperty)
{
    Guid guid = currentProperty.Id;

    // Iterate through the StylusPointProperties to find the StylusPointProperty
    // that matches currentProperty, then return the name.
    foreach (FieldInfo theFieldInfo
        in typeof(StylusPointProperties).GetFields())
    {
        StylusPointProperty property = (StylusPointProperty) theFieldInfo.GetValue(currentProperty);
        if (property.Id == guid)
        {
            return theFieldInfo.Name;
        }
    }
    return "Not found";
}

' Use reflection to get the name of currentProperty.
Private Function GetStylusPointPropertyName(ByVal currentProperty As StylusPointProperty) As String 
    Dim guid As Guid = currentProperty.Id
    
    ' Iterate through the StylusPointProperties to find the StylusPointProperty
    ' that matches currentProperty, then return the name.
    Dim theFieldInfo As FieldInfo

    For Each theFieldInfo In GetType(StylusPointProperties).GetFields()

        Dim pointProperty As StylusPointProperty = _
            CType(theFieldInfo.GetValue(currentProperty), StylusPointProperty)

        If pointProperty.Id = guid Then
            Return theFieldInfo.Name
        End If

    Next theFieldInfo

    Return "Not found"

End Function 'GetStylusPointPropertyName

注解

属性的值 PressureFactor 表示为介于 0 和 1 之间的值。 值为 0 表示未施加压力，而值为 1 表示应用的最大压力量。 值为 0.5 表示应用最大压力的 50%，依此而过。