使用手寫筆繪製畫布 - Windows 10通用應用程序C＃

Question

我正在使用C＃中的Windows 10通用應用程序。我有一個用戶可以繪製簽名的畫布控件。我附加了PointerPressed，PointerMoved，PointerReleased，附有畫布控件的PointerExited事件，我使用下面的代碼來繪製簽名。

 private void InkCanvas_PointerMoved(object sender, PointerRoutedEventArgs e) 
      { 
       try 
       { 
        if (e.Pointer.PointerId == _penID) 
        { 
         PointerPoint pt = e.GetCurrentPoint(sender as Canvas); 

         // Render a red line on the canvas as the pointer moves. 
         // Distance() is an application-defined function that tests 
         // whether the pointer has moved far enough to justify 
         // drawing a new line. 
         currentContactPt = pt.Position; 
         x1 = _previousContactPt.X; 
         y1 = _previousContactPt.Y; 
         x2 = currentContactPt.X; 
         y2 = currentContactPt.Y; 

         if (Distance(x1, y1, x2, y2) > 2.0) 
         { 
          Line line = new Line() 
          { 
           X1 = x1, 
           Y1 = y1, 
           X2 = x2, 
           Y2 = y2, 
           StrokeThickness = 4.0, 
           Stroke = new SolidColorBrush(Colors.Blue) 
          }; 

          _previousContactPt = currentContactPt; 

          // Draw the line on the canvas by adding the Line object as 
          // a child of the Canvas object. 
          ((Canvas)(sender)).Children.Add(line); 

          // Pass the pointer information to the InkManager. 
          _inkManager.ProcessPointerUpdate(pt); 
         } 
        } 

        else if (e.Pointer.PointerId == _touchID) 
        { 
         // Process touch input 
        } 
       } 
       catch (Exception ex) 
       { 
        LogUtility.Log("InkCanvas_PointerMoved Exception: " + ex.Message + "\nInnerException: " + ex.InnerException); 
       } 

      } 

public void InkCanvas_PointerPressed(object sender, PointerRoutedEventArgs e) 
     { 
      try 
      { 
       // Get information about the pointer location. 
       PointerPoint pt = e.GetCurrentPoint(((Canvas)(sender))); 
       _previousContactPt = pt.Position; 

       // Accept input only from a pen or mouse with the left button pressed. 
       PointerDeviceType pointerDevType = e.Pointer.PointerDeviceType; 
       if (pointerDevType == PointerDeviceType.Pen || 
         pointerDevType == PointerDeviceType.Mouse && 
         pt.Properties.IsLeftButtonPressed) 
       { 
        // Pass the pointer information to the InkManager. 
        _inkManager.ProcessPointerDown(pt); 
        _penID = pt.PointerId; 

        e.Handled = true; 
       } 

       else if (pointerDevType == PointerDeviceType.Touch) 
       { 
        // Process touch input 
       } 
      } 
      catch (Exception ex) 
      { 
       LogUtility.Log("InkCanvas_PointerPressed Exception: " + ex.Message + "\nInnerException: " + ex.InnerException); 
      } 
     } 
public void InkCanvas_PointerReleased(object sender, PointerRoutedEventArgs e) 
     { 
      try 
      { 
       if (e.Pointer.PointerId == _penID) 
       { 
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(sender as Canvas); 

        // Pass the pointer information to the InkManager. 
        _inkManager.ProcessPointerUp(pt); 
       } 

       else if (e.Pointer.PointerId == _touchID) 
       { 
        // Process touch input 
       } 

       _touchID = 0; 
       _penID = 0; 

       // Call an application-defined function to render the ink strokes. 


       e.Handled = true; 
      } 
      catch (Exception ex) 
      { 
       LogUtility.Log("InkCanvas_PointerReleased Exception: " + ex.Message + "\nInnerException: " + ex.InnerException); 
      } 
     } 

      private double Distance(double x1, double y1, double x2, double y2) 
      { 
       double d = 0; 
       d = Math.Sqrt(Math.Pow((x2 - x1), 2) + Math.Pow((y2 - y1), 2)); 
       return d; 
      } 

它適用於鼠標，但不適用於手寫筆。我無法找到任何其他方式來做到這一點。 你能告訴我修理手寫筆嗎？

Answer 1

我相信InkCanvas是做這些東西的最佳控制，請查看here瞭解更多詳情。

Answer 2

我發現it有幫助。它解決了手寫筆觸摸問題。