winform快速开发平台 -> 工作流组件(仿GooFlow)

对于web方向的工作流，一直在用gooflow对于目前我的winform开发平台却没有较好的工作流组件。

　针对目前的项目经验告诉我们。一个工作流控件是很必要的。当然在winform方面的工作流第三方组件在网上找了很久，也没有发现自己比较心仪的组件。

对于工作流组件通过web方式来实现具有绝对的优势。我的这套winform平台当然也不能少了工作流组件。

通过winform来实现自己的工作流组件，目前我想到的指能通过GDI+重绘的方式来实现工作流的方案。

　　说干就干，如下图这是我通过GDI+绘制的工作流控件:

设计思想:

控件中我们需要一些定义的节点：如开始、结束、自定义节点、画线，和一个内容画布组成

通过抽象出线、点、以及item。进行重绘。

画布进行双缓冲来解决绘制时导致的出线闪屏问题。

简单介绍:

画布中的网格绘制方法：

var gridPen = new Pen(Color.Silver)
{
    DashStyle = DashStyle.Custom,
    DashPattern = new float[] { 2f, 2f }
};
 for (int column = 0; column < (int)Math.Ceiling((double)this.Width / (double)gridAverage); column++)
{
    bufferGraphics.DrawLine(gridPen, new Point(column * gridAverage, 0), new Point(column * gridAverage, this.Height));
}
 for (int row = 0; row < (int)Math.Ceiling((double)this.Height / (double)gridAverage); row++)
{
    bufferGraphics.DrawLine(gridPen, new Point(0, row * gridAverage), new Point(this.Width, row * gridAverage));
} 

　绘制节点抽象类型代码:

public enum ItemType
{
    /// <summary>
    /// 开始
    /// </summary>
    Start,
    /// <summary>
    /// 工作流
    /// </summary>
    Custom, 
    /// <summary>
    /// 线
    /// </summary>
    Line,
    /// <summary>
    /// 结束
    /// </summary>
    End
 }

绘制连线

public void DrawLine(Graphics grp, Pen pen)
{
    if (m_startPoint == null || m_endPoint == null) return;
 
    var startX = m_startPoint.ItemLocate.X + m_startPoint.ItemImage.Width / 2;
    var startY = m_startPoint.ItemLocate.Y + m_startPoint.ItemImage.Height / 2;
 
    var endX = m_endPoint.ItemLocate.X + m_endPoint.ItemImage.Width / 2;
    var endY = m_endPoint.ItemLocate.Y + m_endPoint.ItemImage.Height / 2;
 
    #region 计算开始点位置
    if (m_startPoint.ItemLocate.X < m_endPoint.ItemLocate.X)
    {
        if (m_startPoint.ItemLocate.Y < m_endPoint.ItemLocate.Y - m_startPoint.ItemLocate.Y)
        {
            startX = m_startPoint.ItemLocate.X + m_startPoint.ItemImage.Width / 2;
            startY = m_startPoint.ItemLocate.Y + m_startPoint.ItemImage.Height;
        }
        else if (m_startPoint.ItemLocate.Y < m_endPoint.ItemLocate.Y + m_endPoint.ItemImage.Height)
        {
            startX = m_startPoint.ItemLocate.X + m_startPoint.ItemImage.Width;
            startY = m_startPoint.ItemLocate.Y + m_startPoint.ItemImage.Height / 2;
        }
        else
        {
            startX = m_startPoint.ItemLocate.X + m_startPoint.ItemImage.Width / 2;
            startY = m_startPoint.ItemLocate.Y;
        }
    }
    else
    {
        if (m_startPoint.ItemLocate.Y < m_endPoint.ItemLocate.Y - m_startPoint.ItemLocate.Y)
        {
            startX = m_startPoint.ItemLocate.X + m_startPoint.ItemImage.Width / 2;
            startY = m_startPoint.ItemLocate.Y + m_startPoint.ItemImage.Height;
        }
        else if (m_startPoint.ItemLocate.Y < m_endPoint.ItemLocate.Y + m_endPoint.ItemImage.Height)
        {
            startX = m_startPoint.ItemLocate.X;
            startY = m_startPoint.ItemLocate.Y + m_startPoint.ItemImage.Height / 2;
        }
        else
        {
            startX = m_startPoint.ItemLocate.X + m_startPoint.ItemImage.Width / 2;
            startY = m_startPoint.ItemLocate.Y;
        }
    }
    #endregion
 
    #region 计算结束点位置
 
    if (m_startPoint.ItemLocate.X < m_endPoint.ItemLocate.X)
    {
        if (m_startPoint.ItemLocate.Y < m_endPoint.ItemLocate.Y - m_startPoint.ItemLocate.Y)
        {
            endX = m_endPoint.ItemLocate.X + m_endPoint.ItemImage.Width / 2;
            endY = m_endPoint.ItemLocate.Y;
        }
        else if (m_startPoint.ItemLocate.Y < m_endPoint.ItemLocate.Y + m_endPoint.ItemImage.Height)
        {
            endX = m_endPoint.ItemLocate.X;
            endY = m_endPoint.ItemLocate.Y + m_endPoint.ItemImage.Height / 2;
        }
        else
        {
            endX = m_endPoint.ItemLocate.X + m_endPoint.ItemImage.Width / 2;
            endY = m_endPoint.ItemLocate.Y + m_endPoint.ItemImage.Height;
        }
    }
    else
    {
        if (m_startPoint.ItemLocate.Y < m_endPoint.ItemLocate.Y - m_startPoint.ItemLocate.Y)
        {
            endX = m_endPoint.ItemLocate.X + m_endPoint.ItemImage.Width / 2;
            endY = m_endPoint.ItemLocate.Y;
        }
        else if (m_startPoint.ItemLocate.Y < m_endPoint.ItemLocate.Y + m_endPoint.ItemImage.Height)
        {
            endX = m_endPoint.ItemLocate.X + m_endPoint.ItemImage.Width;
            endY = m_endPoint.ItemLocate.Y + m_endPoint.ItemImage.Height / 2;
        }
        else
        {
            endX = m_endPoint.ItemLocate.X + m_endPoint.ItemImage.Width / 2;
            endY = m_endPoint.ItemLocate.Y + m_endPoint.ItemImage.Height;
        }
    }
    #endregion
    var startPoint = new Point(startX, startY);
    var endPoint = new Point(endX, endY);
 
    grp.DrawLine(pen, startPoint, endPoint);
}