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GridControl的数据源只有两列的DataTable，列分别为Code和Caption。

开始拖拽的思路是：在GridControl的MouseDown以及MoseMove里处理开始拖拽，在richEditControl里执行并且结束拖拽。

以下为GridControl的MouseDown以及MouseMove方法：

DevExpress.XtraGrid.Views.Grid.ViewInfo.GridHitInfo m_DownHitInfo_TuXing = null;  
private void gv_TuXing_MouseDown(object sender, MouseEventArgs e)  
        {  
            DevExpress.XtraGrid.Views.Grid.ViewInfo.GridHitInfo hi = this.gv_TuXing.CalcHitInfo(new Point(e.X, e.Y));  
            int iMouseRowHandle = hi.RowHandle;  
            if (iMouseRowHandle >= 0 && e.Button == MouseButtons.Left)  
            {  
                m_DownHitInfo_TuXing = hi;  
            }  
        }  
  
        private void gv_TuXing_MouseMove(object sender, MouseEventArgs e)  
        {  
            GridView view = sender as GridView;  
            if (e.Button == MouseButtons.Left && m_DownHitInfo_TuXing != null)  
            {  
                Size dragSize = SystemInformation.DragSize;  
                Rectangle dragRect = new Rectangle(new Point(m_DownHitInfo_TuXing.HitPoint.X - dragSize.Width / 2, m_DownHitInfo_TuXing.HitPoint.Y - dragSize.Height / 2), dragSize);  
  
                //当鼠标离开原来的控件区域之后才显示拖拽效果  
                if (!dragRect.Contains(new Point(e.X, e.Y)))  
                {  
                    m_TmrDragDropCanRun = true;  
                    tmr_DragDrop.Start();  
                    DataRow row = view.GetDataRow(m_DownHitInfo_TuXing.RowHandle);  
                    Model.DragDropData modelData = new Model.DragDropData();  
                    modelData.Sender = gc_TuXing;  
                    modelData.Data = row;  
                    view.GridControl.DoDragDrop(modelData, DragDropEffects.Move);  
                    m_DownHitInfo_TuXing = null;  
                    DevExpress.Utils.DXMouseEventArgs.GetMouseArgs(e).Handled = true;  
                }  
            }  
        }

下面这个判断保证了只有当鼠标移出GridControl的范围之后才会触发GridControl的DoDragDrop。

if (!dragRect.Contains(new Point(e.X, e.Y))) 

如果你按住鼠标左键不放，都是处于DragDrop状态，这时候有个神奇的事情，所有控件的MouseMove方法都失效了。

我们来处理一下richEditControl的接收，这里要处理两个方法DragOver以及DragDrop，DragOver在鼠标进入richEditControl区域时改变鼠标样式，DragDrop处理在richEditControl上释放鼠标时处理以及结束拖拽。

    private void rec_EMR_DragOver(object sender, DragEventArgs e)  
            {  
                rec_EMR.Select();  
                if (e.Data.GetDataPresent(typeof(Model.DragDropData)))  
                    e.Effect = DragDropEffects.Move;  
                else  
                    e.Effect = DragDropEffects.None;  
            }  
      
            private void rec_EMR_DragDrop(object sender, DragEventArgs e)  
            {  
                try  
                {  
                    m_TmrDragDropCanRun = false;  
                    tmr_DragDrop.Stop();  
                    Model.DragDropData modelData = (Model.DragDropData)e.Data.GetData(typeof(Model.DragDropData));  
                    switch (modelData.Sender.Name)  
                    {  
                        case "gc_TuXing":  
                            //插入图形  
                            string strImageID = ((DataRow)modelData.Data)["Code"].ToString();  
                            Image imgInsert = m_EMR_BLL.EMR_Image_Get_By_Id(strImageID);  
                            rec_EMR.Document.InsertImage(rec_EMR.Document.CaretPosition, imgInsert);  
                            break;  
                        default:  
                            break;  
                    }  
                }  
                catch (Exception ex)  
                {  
                    XtraMessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);  
                }  
                finally  
                {  
      
                }  
            }  

其中的Model.DragDropData是我自行封装的数据类，两个属性分别对应数据的发送者以及数据：

    using System;  
    using System.Collections.Generic;  
    using System.Linq;  
    using System.Text;  
      
    namespace ElectronicMedicalRecords.Model  
    {  
        public class DragDropData  
        {  
            public System.Windows.Forms.Control Sender { get; set; }  
      
            public object Data { get; set; }  
        }  
    }  

那么通过数据的发送者就可以判断接收的是什么类型的数据以便对具体的情况进行具体的处理。

最后因为拖拽事件过程中所有MouseMove事件都失效，为了解决在richEditControl中不能进行插入符跟随鼠标定位的问题，在界面上添加了一个Timer，每0.5秒进行一次插入符定位处理以实现控制拖拽数据插入位置的问题，代码如下：

    private bool m_TmrDragDropCanRun = false;  
    private void tmr_DragDrop_Tick(object sender, EventArgs e)  
            {  
                //在拖拽时定位鼠标坐标  
                if (m_TmrDragDropCanRun)  
                {  
                    tmr_DragDrop.Stop();  
                    Point pMouse = Cursor.Position;  
                    Point pEMR_Edit = this.rec_EMR.PointToScreen(rec_EMR.Location);  
                    Point pTruePoint = new Point(pMouse.X - pEMR_Edit.X, pMouse.Y - pEMR_Edit.Y);  
                    Point docPoint = Units.PixelsToDocuments(pTruePoint,  
                rec_EMR.DpiX, rec_EMR.DpiY);  
                    DevExpress.XtraRichEdit.API.Native.DocumentPosition pos = rec_EMR.GetPositionFromPoint(docPoint);  
                    if (pos != null)  
                    {  
                        bsi_BianJiLeiXing.Caption = pos.ToString();  
                        rec_EMR.Document.CaretPosition = pos;  
                    }  
                    else bsi_BianJiLeiXing.Caption = "Mouse:(" + pMouse.X + "|" + pMouse.Y + " E:(" + pTruePoint.X + "|" + pTruePoint.Y + ")";  
                    if (m_TmrDragDropCanRun)  
                    {  
                        tmr_DragDrop.Start();  
                    }  
                }  
                else  
                {  
                    tmr_DragDrop.Stop();  
                }  
            }  

转载自//blog.csdn.net/a237428367/article/details/7888776

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