InkPicture.DesiredPacketDescription 屬性

發行項
10/29/2008

取得或設定與 InkPicture 物件上繪製之筆墨關聯的封包方面的所需資訊。

命名空間： Microsoft.Ink
組件： Microsoft.Ink (在 Microsoft.Ink.dll 中)

語法

'宣告
<BrowsableAttribute(False)> _
Public Property DesiredPacketDescription As Guid()
'用途
Dim instance As InkPicture
Dim value As Guid()

value = instance.DesiredPacketDescription

instance.DesiredPacketDescription = value

[BrowsableAttribute(false)]
public Guid[] DesiredPacketDescription { get; set; }

[BrowsableAttribute(false)]
public:
property array<Guid>^ DesiredPacketDescription {
    array<Guid>^ get ();
    void set (array<Guid>^ value);
}

/** @property */
/** @attribute BrowsableAttribute(false) */
public Guid[] get_DesiredPacketDescription()
/** @property */
/** @attribute BrowsableAttribute(false) */
public  void set_DesiredPacketDescription(Guid[] value)

public function get DesiredPacketDescription () : Guid[]
public function set DesiredPacketDescription (value : Guid[])

屬性值

型別：array<System.Guid[]
Guid (英文) 物件的陣列，每個物件都表示與 InkPicture 物件上繪製之筆墨關聯的封包方面的資訊。

備註

封包描述是來自 PacketProperty 物件的 Guid (英文) 物件陣列。

DesiredPacketDescription 預設會包含來自 PacketProperty 物件的 X、Y 和 NormalPressure。如果將 DesiredPacketDescription 設定為其他項目，則也會加入 X 和 Y。例如，如果只將 DesiredPacketDescription 設定為 ButtonPressure，get 則會傳回 {X, Y, ButtonPressure}，而非僅是 {ButtonPressure}。

當 DesiredPacketDescription 是設定為包含 PacketStatus 的項目時，PacketStatus 會被加到第三個位置。例如，如果將 DesiredPacketDescription 設定為 (a, b, c, d, PacketStatus, e, f)，get 則會傳回 (X, Y, PacketStatus, a, b, c, d, e, f)。

在多重手寫板模式中，這是所有手寫板裝置的封包描述。如果有任何裝置不支援已知的封包描述屬性，則不會傳回屬性資料。

在將 InkEnabled 屬性從 false 變更為 true 之前，對這個屬性所做的變更並不會影響傳入的封包資料。

範例

下列範例為您示範如何使用 DesiredPacketDescription 屬性，表達對來自 PacketProperty 物件的 Guid (英文) 物件感興趣，然後在 NewPackets 期間使用公開的封包屬性。

首先，會初始化 DesiredPacketDescription 屬性並指派事件處理常式。

' Express interest in PacketStatus, TimerTick, and NormalPressure
' X and Y will be added automatically
Dim PacketDesc As Guid() = New Guid() _
    { _
        PacketProperty.PacketStatus, _
        PacketProperty.TimerTick, _
        PacketProperty.NormalPressure _
    }

' mInkObject can be InkCollector, InkOverlay, or InkPicture
mInkObject.DesiredPacketDescription = PacketDesc
' assign event handlers
AddHandler mInkObject.CursorInRange, New InkCollectorCursorInRangeEventHandler(AddressOf mInkObject_CursorInRange)
AddHandler mInkObject.NewPackets, New InkCollectorNewPacketsEventHandler(AddressOf mInkObject_NewPackets)

// Express interest in PacketStatus, TimerTick, and NormalPressure
// X and Y will be added automatically
Guid[] PacketDesc = new Guid[] 
{
    PacketProperty.PacketStatus,
    PacketProperty.TimerTick,
    PacketProperty.NormalPressure
};
// mInkObject can be InkCollector, InkOverlay, or InkPicture
mInkObject.DesiredPacketDescription = PacketDesc;
// assign event handlers
mInkObject.CursorInRange += new InkCollectorCursorInRangeEventHandler(mInkObject_CursorInRange);
mInkObject.NewPackets += new InkCollectorNewPacketsEventHandler(mInkObject_NewPackets);

當 CursorInRange 事件引發時，會檢查 InkPicture 物件是否為第一次與這個特定 Cursor 物件聯繫。如果是，則會將 DefaultDrawingAttributes 屬性的複製品指派給 DrawingAttributes 屬性。這樣可確定後續對 DrawingAttributes 屬性的存取不會擲回 null 參考例外狀況。

Private Sub mInkObject_CursorInRange(ByVal sender As Object, ByVal e As InkCollectorCursorInRangeEventArgs)
    Const MOUSE_CURSOR_ID As Integer = 1
    If e.NewCursor Then
        ' mInkObject can be InkCollector, InkOverlay, or InkPicture
        e.Cursor.DrawingAttributes = mInkObject.DefaultDrawingAttributes.Clone()
        ' if this cursor is the mouse, we'll set color to red
        If (MOUSE_CURSOR_ID = e.Cursor.Id) Then
            e.Cursor.DrawingAttributes.Color = Color.Red
        End If

    End If
End Sub

private void mInkObject_CursorInRange(object sender, InkCollectorCursorInRangeEventArgs e)
{
    const int MOUSE_CURSOR_ID = 1;

    if (e.NewCursor)
    {
        // mInkObject can be InkCollector, InkOverlay, or InkPicture
        e.Cursor.DrawingAttributes = mInkObject.DefaultDrawingAttributes.Clone();
        // if this cursor is the mouse, we'll set color to red
        if (MOUSE_CURSOR_ID == e.Cursor.Id)
        {
            e.Cursor.DrawingAttributes.Color = Color.Red;
        }
    }
}

當 NewPackets 事件引發時，會檢查 NormalPressure 是否包含在封包資料中。如果有包含的話，則會在狀態標籤上顯示筆壓資訊，而且會修改 DrawingAttributes 屬性。

Private Sub mInkObject_NewPackets(ByVal sender As Object, ByVal e As InkCollectorNewPacketsEventArgs)

    ' find the NormalPressure PacketProperty
    ' Set NormalPressure to -1 if not there, as some digitizers won't support it
    Dim PacketDesc As Guid() = e.Stroke.PacketDescription
    Dim NormalPressure As Integer = -1

    For k As Integer = 0 To PacketDesc.Length - 1
        If PacketDesc(k) = PacketProperty.NormalPressure Then
            ' for simplicity, in case of multiple packets, use the first packet only
            NormalPressure = e.PacketData(k)
        End If
    Next k

    ' If we have the NormalPressure information
    ' change DrawingAttributes according to the NormalPressure
    ' Note that the change does not take effect until the next stroke
    If NormalPressure <> -1 Then
        ' display the pressure on a status label
        Me.statusLabelPressure.Text = NormalPressure.ToString()
        e.Cursor.DrawingAttributes.Width = NormalPressure * 4
        ' if pressure is above 127, change color to Red
        If NormalPressure > 127 Then
            e.Cursor.DrawingAttributes.Color = Color.Red
        Else
            e.Cursor.DrawingAttributes.Color = mInkObject.DefaultDrawingAttributes.Color
        End If
    End If

End Sub

private void mInkObject_NewPackets(object sender, InkCollectorNewPacketsEventArgs e)
{
    // find the NormalPressure PacketProperty
    // Set NormalPressure to -1 if not there, as some digitizers won't support it
    Guid[] PacketDesc = e.Stroke.PacketDescription;
    int NormalPressure = -1;
    for (int k = 0; k < PacketDesc.Length; k++)
    {
        if (PacketDesc[k] == PacketProperty.NormalPressure)
        {
            // for simplicity, in case of multiple packets, use the first packet only
            NormalPressure = e.PacketData[k];
        }
    }

    // If we have the NormalPressure information
    // change DrawingAttributes according to the NormalPressure
    // Note that the change does not take effect until the next stroke
    if (NormalPressure != -1)
    {
        // display the pressure on a status label
        this.statusLabelPressure.Text = NormalPressure.ToString();
        e.Cursor.DrawingAttributes.Width = NormalPressure * 4;
        // if pressure is above 127, change color to Red
        if (NormalPressure > 127)
        {
            e.Cursor.DrawingAttributes.Color = Color.Red;
        }
        else
        {
            e.Cursor.DrawingAttributes.Color = mInkObject.DefaultDrawingAttributes.Color;
        }
    }
}