GraphicsPathIterator.NextSubpath Method

Definition

Namespace:

System.Drawing.Drawing2D

Assembly:

System.Drawing.Common.dll

Moves the subpath to the next subpath in the specified GraphicsPath.

Overloads

NextSubpath(GraphicsPath, Boolean)	Gets the next figure (subpath) from the associated path of this GraphicsPathIterator.
NextSubpath(Int32, Int32, Boolean)	Moves the GraphicsPathIterator to the next subpath in the path. The start index and end index of the next subpath are contained in the [out] parameters.

NextSubpath(GraphicsPath, Boolean)

Gets the next figure (subpath) from the associated path of this GraphicsPathIterator.

public:
 int NextSubpath(System::Drawing::Drawing2D::GraphicsPath ^ path, [Runtime::InteropServices::Out] bool % isClosed);

public int NextSubpath (System.Drawing.Drawing2D.GraphicsPath path, out bool isClosed);

member this.NextSubpath : System.Drawing.Drawing2D.GraphicsPath * bool -> int

Public Function NextSubpath (path As GraphicsPath, ByRef isClosed As Boolean) As Integer

Parameters

path

GraphicsPath

A GraphicsPath that is to have its data points set to match the data points of the retrieved figure (subpath) for this iterator.

isClosed

Boolean

[out] Indicates whether the current subpath is closed. It is true if the if the figure is closed, otherwise it is false.

Returns

Int32

The number of data points in the retrieved figure (subpath). If there are no more figures to retrieve, zero is returned.

Examples

The following example is designed for use with Windows Forms, and it requires PaintEventArgs e, an OnPaint event object. The code performs the following actions:

• Creates a GraphicsPath object.

• Adds three lines, a rectangle, an ellipse, and two markers.

• Lists the values of all the path's points to the left side of the screen.

• Creates a GraphicsPathIterator object.

• Creates a GraphicsPath object, myPathSection, to receive copied points.

• Calls the NextSubpath method, which iterates to the third subpath (figure) and copies all the points contained in that subpath to the myPathSection path, and also returns the number of points copied to subpathPoints.

• Lists the subpath number and number of points it contains to the right side of the screen.

void NextSubpathExample2( PaintEventArgs^ e )
{
   // Create a graphics path.
   GraphicsPath^ myPath = gcnew GraphicsPath;

   // Set up primitives to add to myPath.
   array<Point>^ myPoints = {Point(20,20),Point(120,120),Point(20,120),Point(20,20)};
   Rectangle myRect = Rectangle(120,120,100,100);

   // Add 3 lines, a rectangle, an ellipse, and 2 markers.
   myPath->AddLines( myPoints );
   myPath->SetMarkers();
   myPath->AddRectangle( myRect );
   myPath->SetMarkers();
   myPath->AddEllipse( 220, 220, 100, 100 );

   // Get the total number of points for the path,
   // and the arrays of the points and types.
   int myPathPointCount = myPath->PointCount;
   array<PointF>^myPathPoints = myPath->PathPoints;
   array<Byte>^myPathTypes = myPath->PathTypes;

   // Set up variables for listing all of the path's
   // points to the screen.
   int i;
   float j = 20;
   System::Drawing::Font^ myFont = gcnew System::Drawing::Font( "Arial",8 );
   SolidBrush^ myBrush = gcnew SolidBrush( Color::Black );

   // List the values of all the path points and types to the screen.
   for ( i = 0; i < myPathPointCount; i++ )
   {
      e->Graphics->DrawString( myPathPoints[ i ].X + ", " + myPathPoints[ i ].Y + ", " + myPathTypes[ i ], myFont, myBrush, 20, j );
      j += 20;
   }

   // Create a GraphicsPathIterator for myPath.
   GraphicsPathIterator^ myPathIterator = gcnew GraphicsPathIterator( myPath );

   // Rewind the iterator.
   myPathIterator->Rewind();

   // Create the GraphicsPath section.
   GraphicsPath^ myPathSection = gcnew GraphicsPath;

   // Iterate to the 3rd subpath and list the number of points therein
   // to the screen.
   int subpathPoints;
   bool IsClosed2;

   // Iterate to the third subpath.
   subpathPoints = myPathIterator->NextSubpath( myPathSection, IsClosed2 );
   subpathPoints = myPathIterator->NextSubpath( myPathSection, IsClosed2 );
   subpathPoints = myPathIterator->NextSubpath( myPathSection, IsClosed2 );

   // Write the number of subpath points to the screen.
   e->Graphics->DrawString( String::Format( "Subpath: 3   Num Points: {0}", subpathPoints ), myFont, myBrush, 200, 20 );
}

public void NextSubpathExample2(PaintEventArgs e)
{
         
    // Create a graphics path.
    GraphicsPath myPath = new GraphicsPath();
         
    // Set up primitives to add to myPath.
    Point[] myPoints = {new Point(20, 20), new Point(120, 120), 
        new Point(20, 120),new Point(20, 20) }; 
    Rectangle myRect = new Rectangle(120, 120, 100, 100);
         
    // Add 3 lines, a rectangle, an ellipse, and 2 markers.
    myPath.AddLines(myPoints);
    myPath.SetMarkers();
    myPath.AddRectangle(myRect);
    myPath.SetMarkers();
    myPath.AddEllipse(220, 220, 100, 100);
         
    // Get the total number of points for the path,
         
    // and the arrays of the points and types.
    int myPathPointCount = myPath.PointCount;
    PointF[] myPathPoints = myPath.PathPoints;
    byte[] myPathTypes = myPath.PathTypes;
         
    // Set up variables for listing all of the path's
         
    // points to the screen.
    int i;
    float j = 20;
    Font myFont = new Font("Arial", 8);
    SolidBrush myBrush = new SolidBrush(Color.Black);
         
    // List the values of all the path points and types to the screen.
    for(i=0; i<myPathPointCount; i++)
    {
        e.Graphics.DrawString(myPathPoints[i].X.ToString()+
            ", " + myPathPoints[i].Y.ToString() + ", " +
            myPathTypes[i].ToString(),
            myFont,
            myBrush,
            20,
            j);
        j+=20;
    }
         
    // Create a GraphicsPathIterator for myPath.
    GraphicsPathIterator myPathIterator = new
        GraphicsPathIterator(myPath);
         
    // Rewind the iterator.
    myPathIterator.Rewind();
         
    // Create the GraphicsPath section.
    GraphicsPath myPathSection = new GraphicsPath();
         
    // Iterate to the 3rd subpath and list the number of points therein
         
    // to the screen.
    int subpathPoints;
    bool IsClosed2;
         
    // Iterate to the third subpath.
    subpathPoints = myPathIterator.NextSubpath(
        myPathSection, out IsClosed2);
    subpathPoints = myPathIterator.NextSubpath(
        myPathSection, out IsClosed2);
    subpathPoints = myPathIterator.NextSubpath(
        myPathSection, out IsClosed2);
         
    // Write the number of subpath points to the screen.
    e.Graphics.DrawString("Subpath: 3"  +
        "   Num Points: " +
        subpathPoints.ToString(),
        myFont,
        myBrush,
        200,
        20);
}

Public Sub NextSubpathExample2(ByVal e As PaintEventArgs)

    ' Create a graphics path.
    Dim myPath As New GraphicsPath

    ' Set up primitives to add to myPath.
    Dim myPoints As Point() = {New Point(20, 20), _
        New Point(120, 120), New Point(20, 120), New Point(20, 20)}
    Dim myRect As New Rectangle(120, 120, 100, 100)

    ' Add 3 lines, a rectangle, an ellipse, and 2 markers.
    myPath.AddLines(myPoints)
    myPath.SetMarkers()
    myPath.AddRectangle(myRect)
    myPath.SetMarkers()
    myPath.AddEllipse(220, 220, 100, 100)

    ' Get the total number of points for the path,

    ' and the arrays of the points and types.
    Dim myPathPointCount As Integer = myPath.PointCount
    Dim myPathPoints As PointF() = myPath.PathPoints
    Dim myPathTypes As Byte() = myPath.PathTypes

    ' Set up variables for drawing the array
    ' of points to the screen.
    Dim i As Integer
    Dim j As Single = 20
    Dim myFont As New Font("Arial", 8)
    Dim myBrush As New SolidBrush(Color.Black)

    ' Draw the set of path points and types to the screen.
    For i = 0 To myPathPointCount - 1
        e.Graphics.DrawString(myPathPoints(i).X.ToString() + _
            ", " + myPathPoints(i).Y.ToString() + ", " + _
            myPathTypes(i).ToString(), myFont, myBrush, 20, j)
        j += 20
    Next i

    ' Create a GraphicsPathIterator for myPath.
    Dim myPathIterator As New GraphicsPathIterator(myPath)

    ' Rewind the iterator.
    myPathIterator.Rewind()

    ' Create the GraphicsPath section.
    Dim myPathSection As New GraphicsPath

    ' Draw the 3rd subpath and the number of points therein
    ' to the screen.
    Dim subpathPoints As Integer
    Dim IsClosed2 As Boolean

    ' Iterate to the third subpath.
    subpathPoints = myPathIterator.NextSubpath(myPathSection, _
        IsClosed2)
    subpathPoints = myPathIterator.NextSubpath(myPathSection, _
        IsClosed2)
    subpathPoints = myPathIterator.NextSubpath(myPathSection, _
        IsClosed2)

    ' Write the number of subpath points to the screen.
    e.Graphics.DrawString("Subpath: 3" + "   Num Points: " + _
    subpathPoints.ToString(), myFont, myBrush, 200, 20)
End Sub

NextSubpath(Int32, Int32, Boolean)

Moves the GraphicsPathIterator to the next subpath in the path. The start index and end index of the next subpath are contained in the [out] parameters.

public:
 int NextSubpath([Runtime::InteropServices::Out] int % startIndex, [Runtime::InteropServices::Out] int % endIndex, [Runtime::InteropServices::Out] bool % isClosed);

public int NextSubpath (out int startIndex, out int endIndex, out bool isClosed);

member this.NextSubpath : int * int * bool -> int

Public Function NextSubpath (ByRef startIndex As Integer, ByRef endIndex As Integer, ByRef isClosed As Boolean) As Integer

Parameters

startIndex

Int32

[out] Receives the starting index of the next subpath.

endIndex

Int32

[out] Receives the ending index of the next subpath.

isClosed

Boolean

[out] Indicates whether the subpath is closed.

Returns

Int32

The number of subpaths in the GraphicsPath object.

Examples

The following example is designed for use with Windows Forms, and it requires PaintEventArgs e, an OnPaint event object. The code performs the following actions:

• Creates a GraphicsPath object.

• Adds three lines, a rectangle, and an ellipse.

• Draws the values for the array of points to the screen.

• Creates a GraphicsPathIterator object.

• Calls the NextSubpath method.

• Uses the values returned from the iterative calls to NextSubpath to draw the start and stop values for each subpath to the screen.

• Draws the value for the total number of subpaths to the screen.

private:
   void NextSubpathExample( PaintEventArgs^ e )
   {
      // Create the GraphicsPath.
      GraphicsPath^ myPath = gcnew GraphicsPath;
      array<Point>^ myPoints = {Point(20,20),Point(120,120),Point(20,120),Point(20,20)};
      Rectangle myRect = Rectangle(120,120,100,100);

      // Add 3 lines, a rectangle, an ellipse, and 2 markers.
      myPath->AddLines( myPoints );
      myPath->AddRectangle( myRect );
      myPath->AddEllipse( 220, 220, 100, 100 );

      // Get the total number of points for the path,
      // and the arrays of the points and types.
      int myPathPointCount = myPath->PointCount;
      array<PointF>^myPathPoints = myPath->PathPoints;
      array<Byte>^myPathTypes = myPath->PathTypes;

      // Set up variables for drawing the array of
      // points to the screen.
      int i;
      float j = 20;
      System::Drawing::Font^ myFont = gcnew System::Drawing::Font( "Arial",8 );
      SolidBrush^ myBrush = gcnew SolidBrush( Color::Black );

      // Draw the set of path points and types to the screen.
      for ( i = 0; i < myPathPointCount; i++ )
      {
         e->Graphics->DrawString( myPathPoints[ i ].X + ", " + myPathPoints[ i ].Y + ", " + myPathTypes[ i ], myFont, myBrush, 20, j );
         j += 20;
      }

      // Create a GraphicsPathIterator.
      GraphicsPathIterator^ myPathIterator = gcnew GraphicsPathIterator( myPath );
      int myStartIndex;
      int myEndIndex;
      bool myIsClosed;

      // get the number of Subpaths.
      int numSubpaths = myPathIterator->NextSubpath( myPath, myIsClosed );
      numSubpaths -= 1;

      // Rewind the Iterator.
      myPathIterator->Rewind();

      // List the Subpaths to the screen.
      j = 20;
      for ( i = 0; i < numSubpaths; i++ )
      {
         myPathIterator->NextSubpath( myStartIndex, myEndIndex, myIsClosed );
         String^ s = String::Format( "Subpath {0}:  Start: {1}", i, myStartIndex );
         s = s + String::Format( "  End: {0}  IsClosed: {1}", myEndIndex, myIsClosed );
         e->Graphics->DrawString( s, myFont, myBrush, 200, j );
         j += 20;
      }

      // Draw the total number of Subpaths to the screen.
      j += 20;
      e->Graphics->DrawString( String::Format( "Number Subpaths = {0}", numSubpaths ), myFont, myBrush, 200, j );
   }

private void NextSubpathExample(PaintEventArgs e)
{
             
    // Create the GraphicsPath.
    GraphicsPath myPath = new GraphicsPath();
    Point[] myPoints = {new Point(20, 20), new Point(120, 120), 
        new Point(20, 120),new Point(20, 20) }; 
    Rectangle myRect = new Rectangle(120, 120, 100, 100);
             
    // Add 3 lines, a rectangle, an ellipse, and 2 markers.
    myPath.AddLines(myPoints);
    myPath.AddRectangle(myRect);
    myPath.AddEllipse(220, 220, 100, 100);
             
    // Get the total number of points for the path,
             
    // and the arrays of the points and types.
    int myPathPointCount = myPath.PointCount;
    PointF[] myPathPoints = myPath.PathPoints;
    byte[] myPathTypes = myPath.PathTypes;
             
    // Set up variables for drawing the array of
             
    // points to the screen.
    int i;
    float j = 20;
    Font myFont = new Font("Arial", 8);
    SolidBrush myBrush = new SolidBrush(Color.Black);
             
    // Draw the set of path points and types to the screen.
    for(i=0; i < myPathPointCount; i++)
    {
        e.Graphics.DrawString(myPathPoints[i].X.ToString()+
            ", " + myPathPoints[i].Y.ToString() + ", " +
            myPathTypes[i].ToString(),
            myFont,
            myBrush,
            20,
            j);
        j+=20;
    }
             
    // Create a GraphicsPathIterator.
    GraphicsPathIterator myPathIterator = new
        GraphicsPathIterator(myPath);
    int myStartIndex;
    int myEndIndex;
    bool myIsClosed;
             
    // get the number of Subpaths.
    int numSubpaths = myPathIterator.NextSubpath(myPath,
        out myIsClosed);
    numSubpaths -= 1;
             
    // Rewind the Iterator.
    myPathIterator.Rewind();
             
    // List the Subpaths to the screen.
    j=20;
    for(i=0;i<numSubpaths;i++)
    {
        myPathIterator.NextSubpath(out myStartIndex,
            out myEndIndex,
            out myIsClosed);
        e.Graphics.DrawString("Subpath " + i.ToString() +
            ":  Start: " + myStartIndex.ToString()+
            "  End: " + myEndIndex.ToString() +
            "  IsClosed: " + myIsClosed.ToString(),
            myFont,
            myBrush,
            200,
            j);
        j += 20;
    }
             
    // Draw the total number of Subpaths to the screen.
    j += 20;
    e.Graphics.DrawString("Number Subpaths = " +
        numSubpaths.ToString(),
        myFont,
        myBrush,
        200,
        j);
}

Public Sub NextSubpathExample(ByVal e As PaintEventArgs)

    ' Create the GraphicsPath.
    Dim myPath As New GraphicsPath
    Dim myPoints As Point() = {New Point(20, 20), _
    New Point(120, 120), New Point(20, 120), New Point(20, 20)}
    Dim myRect As New Rectangle(120, 120, 100, 100)

    ' Add 3 lines, a rectangle, an ellipse, and 2 markers.
    myPath.AddLines(myPoints)
    myPath.AddRectangle(myRect)
    myPath.AddEllipse(220, 220, 100, 100)

    ' Get the total number of points for the path,
    ' and the arrays of the points and types.
    Dim myPathPointCount As Integer = myPath.PointCount
    Dim myPathPoints As PointF() = myPath.PathPoints
    Dim myPathTypes As Byte() = myPath.PathTypes

    ' Set up variables for drawing the array of points to the screen.
    Dim i As Integer
    Dim j As Single = 20
    Dim myFont As New Font("Arial", 8)
    Dim myBrush As New SolidBrush(Color.Black)

    ' Draw the set of path points and types to the screen.
    For i = 0 To myPathPointCount - 1
        e.Graphics.DrawString(myPathPoints(i).X.ToString() + ", " + _
        myPathPoints(i).Y.ToString() + ", " + _
        myPathTypes(i).ToString(), myFont, myBrush, 20, j)
        j += 20
    Next i

    ' Create a GraphicsPathIterator.
    Dim myPathIterator As New GraphicsPathIterator(myPath)
    Dim myStartIndex As Integer
    Dim myEndIndex As Integer
    Dim myIsClosed As Boolean

    ' get the number of Subpaths.
    Dim numSubpaths As Integer = myPathIterator.NextSubpath(myPath, _
        myIsClosed)
    numSubpaths -= 1

    ' Rewind the Iterator.
    myPathIterator.Rewind()

    ' List the Subpaths to the screen.
    j = 20
    For i = 0 To numSubpaths - 1
        myPathIterator.NextSubpath(myStartIndex, myEndIndex, _
        myIsClosed)
        e.Graphics.DrawString("Subpath " + i.ToString() + _
            ":  Start: " + myStartIndex.ToString() + "  End: " + _
            myEndIndex.ToString() + "  IsClosed: " + _
            myIsClosed.ToString(), myFont, myBrush, 200, j)
        j += 20
    Next i

    ' Draw the total number of Subpaths to the screen.
    j += 20
    e.Graphics.DrawString("Number Subpaths = " + _
        numSubpaths.ToString(), myFont, myBrush, 200, j)
End Sub