VS2010实现画板功能 实例源码下载

【实例截图】

【核心代码】

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace DrawBoard
{
  /// <summary>
  /// Interaction logic for Window1.xaml
  /// </summary>
  public partial class Window1 : Window
  {
    public Window1()
    {
      InitializeComponent();
    }

    private SolidColorBrush color = new SolidColorBrush();
    private double thickness = 1;
    private double opacity = 1;
    private Shape shape;
    private void ColorButton_Click(object sender, RoutedEventArgs e)
    {
      color = (SolidColorBrush)((Rectangle)(sender as RadioButton).Content).Fill;
    }

    private void ThicknessButton_Click(object sender, RoutedEventArgs e)
    {
      thickness = ((Ellipse)(sender as RadioButton).Content).Width;
    }

    private void ShapeButton_Click(object sender, RoutedEventArgs e)
    {
      shape = (Shape)(sender as RadioButton).Content;
    }

    private void Opacity_TextChanged(object sender, TextChangedEventArgs e)
    {
      double.TryParse((sender as TextBox).Text, out opacity);
    }

    private Point startPosition;
    private Shape insertShape;
    private bool drawFlag = false;
    private void Canvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
      drawFlag = true;
      Canvas board = sender as Canvas;
      startPosition = e.GetPosition(board);
      insertShape = CreateShape();
      insertShape.Opacity = opacity / 2;
      Canvas.SetLeft(insertShape, e.GetPosition(board).X);
      Canvas.SetTop(insertShape, e.GetPosition(board).Y);
      board.Children.Add(insertShape);
    }

    private void Canvas_MouseMove(object sender, MouseEventArgs e)
    {
      Canvas board = sender as Canvas;
      if (drawFlag && insertShape != null)
      {
        if (insertShape is Line)
        {
          (insertShape as Line).X1 = 0; (insertShape as Line).X2 = e.GetPosition(board).X - startPosition.X;
          (insertShape as Line).Y1 = 0; (insertShape as Line).Y2 = e.GetPosition(board).Y - startPosition.Y;
        }
        else
        {
          if (e.GetPosition(board).X > startPosition.X)
          {
            insertShape.Width = e.GetPosition(board).X - startPosition.X;
          }
          else
          {
            insertShape.Width = startPosition.X - e.GetPosition(board).X;
            Canvas.SetLeft(insertShape, e.GetPosition(board).X);
          }
          if (e.GetPosition(board).Y > startPosition.Y)
          {
            insertShape.Height = e.GetPosition(board).Y - startPosition.Y;
          }
          else
          {
            insertShape.Height = startPosition.Y - e.GetPosition(board).Y;
            Canvas.SetTop(insertShape, e.GetPosition(board).Y);
          }
        }
      }
    }

    private void Canvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
      drawFlag = false;
      if (insertShape != null)
        insertShape.Opacity = opacity;
    }

    private Shape CreateShape()
    {
      if (shape is Rectangle)
        return new Rectangle() { Fill = color, Stroke = Brushes.Black, StrokeThickness = thickness };
      else if (shape is Ellipse)
        return new Ellipse() { Fill = color, Stroke = Brushes.Black, StrokeThickness = thickness };
      else
        return new Line() { Stroke = (color.Color == Brushes.Transparent.Color?Brushes.Black:color), StrokeThickness = thickness };
    }

  }
}