Matrix.Reset Método

Definição

Namespace:

System.Drawing.Drawing2D

Assembly:

System.Drawing.Common.dll

Redefine esse Matrix ter os elementos da matriz de identidade.

public:
 void Reset();

public void Reset ();

member this.Reset : unit -> unit

Public Sub Reset ()

Exemplos

O exemplo de código a seguir foi projetado para uso com o Windows Forms e requer PaintEventArgse, um objeto de evento Paint. O código executa as seguintes ações:

• Cria uma matriz de dimensionamento.

• Lista os elementos de matriz para a tela.

• Redefine a matriz para identidade.

• Lista os elementos para a tela.

• Converte a matriz em 50 pontos no eixo x e 40 pontos no eixo y.

• Lista os elementos da matriz traduzida para a tela.

• Desenha um retângulo desenhado na tela antes de aplicar a transformação de matriz (o retângulo azul).

• Aplica a transformação ao retângulo.

• Desenha o retângulo transformado é desenhado para a tela (o retângulo vermelho), usando as mesmas coordenadas do retângulo anterior.

Observe que o retângulo vermelho não foi dimensionado (por causa da redefinição), mas foi convertido no eixo x e no eixo y.

public:
   void ResetExample( PaintEventArgs^ e )
   {
      Pen^ myPen = gcnew Pen( Color::Blue,1.0f );
      Pen^ myPen2 = gcnew Pen( Color::Red,1.0f );

      // Create a matrix that scales by 5 in the x direction and
      // by 3 in the y direction.
      Matrix^ myMatrix = gcnew Matrix( 5.0f,0.0f,0.0f,3.0f,0.0f,0.0f );

      // List the matrix elements to the screen.
      ListMatrixElements( e, myMatrix, "Beginning Matrix", 6, 20 );

      // Reset the matrix to identity.
      myMatrix->Reset();

      // Again list the matrix elements to the screen.
      ListMatrixElements2( e, myMatrix, "Matrix After Reset", 6, 40 );

      // Translate the matrix by 50 points in the x-axis and 40 points
      // in the y-axis.
      myMatrix->Translate( 50.0f, 40.0f );

      // List the matrix elements to the screen.
      ListMatrixElements1( e, myMatrix, "Matrix After Translation", 6, 60 );

      // Draw a rectangle to the screen.
      e->Graphics->DrawRectangle( myPen, 0, 0, 100, 100 );

      // Apply the matrix transform to the Graphics.
      e->Graphics->Transform = myMatrix;

      // Draw another rectangle to the screen that has the transform
      // applied.
      e->Graphics->DrawRectangle( myPen2, 0, 0, 100, 100 );
   }

   //-------------------------------------------------------
   // This function is a helper function to
   // list the contents of a matrix.
   //-------------------------------------------------------
   void ListMatrixElements2( PaintEventArgs^ e, Matrix^ matrix, String^ matrixName, int numElements, int y )
   {
      // Set up variables for drawing the array
      // of points to the screen.
      int i;
      float x = 20,X = 200;
      System::Drawing::Font^ myFont = gcnew System::Drawing::Font( "Arial",8 );
      SolidBrush^ myBrush = gcnew SolidBrush( Color::Black );

      // Draw the matrix name to the screen.
      e->Graphics->DrawString( String::Concat( matrixName, ":  " ), myFont, myBrush, (float)x, (float)y );

      // Draw the set of path points and types to the screen.
      for ( i = 0; i < numElements; i++ )
      {
         e->Graphics->DrawString( String::Concat( matrix->Elements[ i ], ", " ), myFont, myBrush, (float)X, (float)y );
         X += 30;
      }
   }

public void ResetExample(PaintEventArgs e)
{
    Pen myPen = new Pen(Color.Blue, 1);
    Pen myPen2 = new Pen(Color.Red, 1);
             
    // Create a matrix that scales by 5 in the x direction and
    // by 3 in the y direction.
    Matrix myMatrix = new Matrix(
        5.0f, 0.0f, 0.0f, 3.0f, 0.0f, 0.0f); 
             
    // List the matrix elements to the screen.
    ListMatrixElements(e, myMatrix, "Beginning Matrix", 6, 20);
             
    // Reset the matrix to identity.
    myMatrix.Reset();
             
    // Again list the matrix elements to the screen.
    ListMatrixElements2(e, myMatrix, "Matrix After Reset", 6, 40);
             
    // Translate the matrix by 50 points in the x-axis and 40 points
    // in the y-axis.
    myMatrix.Translate(50.0f, 40.0f); 
  
    // List the matrix elements to the screen.
    ListMatrixElements1(e, myMatrix, "Matrix After Translation", 6, 60);
             
    // Draw a rectangle to the screen.
    e.Graphics.DrawRectangle(myPen, 0, 0, 100, 100);
             
    // Apply the matrix transform to the Graphics.
    e.Graphics.Transform = myMatrix;
             
    // Draw another rectangle to the screen that has the transform
    // applied.
    e.Graphics.DrawRectangle(myPen2, 0, 0, 100, 100);
}
             
//-------------------------------------------------------
// This function is a helper function to
// list the contents of a matrix.
//-------------------------------------------------------
public void ListMatrixElements2(
    PaintEventArgs e,
    Matrix matrix,
    string matrixName,
    int numElements,
    int y)
{
             
    // Set up variables for drawing the array
    // of points to the screen.
    int i;
    float x = 20, X = 200;
    Font myFont = new Font("Arial", 8);
    SolidBrush myBrush = new SolidBrush(Color.Black);
             
    // Draw the matrix name to the screen.
    e.Graphics.DrawString(
        matrixName + ":  ",
        myFont,
        myBrush,
        x,
        y);
             
    // Draw the set of path points and types to the screen.
    for(i=0; i < numElements; i++)
    {
        e.Graphics.DrawString(
            matrix.Elements[i].ToString() + ", ",
            myFont,
            myBrush,
            X,
            y);
        X += 30;
    }
}

Public Sub ResetExample(ByVal e As PaintEventArgs)
    Dim myPen As New Pen(Color.Blue, 1)
    Dim myPen2 As New Pen(Color.Red, 1)
    Dim myMatrix As New Matrix(5.0F, 0.0F, 0.0F, 3.0F, 0.0F, 0.0F)

    ListMatrixElementsHelper2(e, myMatrix, "Beginning Matrix", 6, 20)
    myMatrix.Reset()
    ListMatrixElementsHelper(e, myMatrix, "Matrix After Reset", 6, 40)

    ' Translate.
    myMatrix.Translate(50.0F, 40.0F)

    ListMatrixElementsHelper(e, myMatrix, "Matrix After Translation", _
        6, 60)
    e.Graphics.DrawRectangle(myPen, 0, 0, 100, 100)
    e.Graphics.Transform = myMatrix
    e.Graphics.DrawRectangle(myPen2, 0, 0, 100, 100)
End Sub

' A helper function to list the contents of a matrix.
Public Sub ListMatrixElementsHelper2(ByVal e As PaintEventArgs, _
ByVal matrix As Matrix, ByVal matrixName As String, ByVal numElements As Integer, _
ByVal y As Integer)

    ' Set up variables for drawing the array
    ' of points to the screen.
    Dim i As Integer
    Dim x As Single = 20
    Dim j As Single = 200
    Dim myFont As New Font("Arial", 8)
    Dim myBrush As New SolidBrush(Color.Black)

    ' Draw the matrix name to the screen.
    e.Graphics.DrawString(matrixName + ":  ", myFont, myBrush, x, y)

    ' Draw the set of path points and types to the screen.
    For i = 0 To numElements - 1
        e.Graphics.DrawString(matrix.Elements(i).ToString() + ", ", _
        myFont, myBrush, j, y)
        j += 30
    Next i
End Sub

Comentários

Os elementos na diagonal principal da matriz de identidade são 1. Todos os outros elementos da matriz de identidade são 0.