Winform中实现ZedGraph滚轮缩放后自动重新加载数据

场景

winforn中设置zedgraph曲线图的属性、坐标轴属性、刻度属性：

https://blog.csdn.net/badao_liumang_qizhi/article/details/100112573

需求是在曲线图上进行滚轮或者鼠标划区域缩放时重新加载数据。

效果如下

 

 

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实现

在包含zedgraph曲线图的窗体中的load方法中进行图形的初始化。

//初始化zedgraph
common.datachart.datacharthelper.initgraphpane(this.zedgraphcontrol1);

在初始化方法中进行滚轮缩放事件的绑定

zgc.zoomevent -= zgc_zoomevent;                     //滚轮缩放事件
zgc.zoomevent += zgc_zoomevent;                     //滚轮缩放事件

 

然后在滚轮缩放事件中

 

private static void zgc_zoomevent(zedgraphcontrol sender, zoomstate oldstate, zoomstate newstate)
        {
            try
            {
               

                refillbeginindex = (int)sender.graphpane.xaxis.scale.min;      //缩放后的开始索引点
                refillendindex = (int)sender.graphpane.xaxis.scale.max;        //缩放后的结束索引点

                #region 重新填充数据

             
                    if (refillbeginindex < 0) refillbeginindex = 0;
                    if (refillendindex >= global.instance.virtualdata.recorddatafilter.count) refillendindex = global.instance.virtualdata.recorddatafilter.count - 1;
                    if (refillendindex < 0) refillendindex = 0;
                    if (refillbeginindex > refillendindex) refillbeginindex = refillendindex;

               

                    int begindatapoint = global.instance.virtualdata.recorddatafilter[refillbeginindex].datapoint;      //保存开始记录的datapoint值
                    int enddatapoint = global.instance.virtualdata.recorddatafilter[refillendindex].datapoint;          //保存结束记录的datapoint值
                    list<wongoing.entity.record> newfilterdata = new list<entity.record>();         //保存新过滤的数据

                    #region 开启一个后台线程，用于重新计算过滤数据，计算完毕刷新曲线

                    stopwatch sw = new stopwatch();
                    sw.restart();
                    using (system.componentmodel.backgroundworker bgworker = new system.componentmodel.backgroundworker())
                    {
                        bgworker.workerreportsprogress = true;          //允许报告进度
                        bgworker.dowork += delegate(object senderobj, system.componentmodel.doworkeventargs dwea)
                        {
                            ienumerable<entity.record> records = global.instance.virtualdata.recorddatalist.where(p => p.datapoint >= begindatapoint && p.datapoint <= enddatapoint);
                            entity.record[] newrecords = records.toarray<entity.record>();
                            bgworker.reportprogress(10);

                            if (records != null)
                            {
                                int count = newrecords.length;
                                sw.stop();
                               
                                sw.restart();
                                if (count > global.appconfig.showpointcount)
                                {
                                    int progressvalue = 10;
                                    int interval = (count - (count % global.appconfig.showpointcount)) / global.appconfig.showpointcount;
                                    int w = 0;
                                    for (int k = 0; k < global.appconfig.showpointcount; k++)
                                    {
                                        newfilterdata.add(newrecords[w]);
                                        w += interval;
                                        if (progressvalue != 10 + (int)(k * 90 / global.appconfig.showpointcount))
                                        {
                                            progressvalue = 10 + (int)(k * 90 / global.appconfig.showpointcount);
                                            bgworker.reportprogress(progressvalue);
                                        }
                                    }
                                }
                                else
                                {
                                    newfilterdata.addrange(newrecords);
                                }
                                sw.stop();
                              
                            }

                            bgworker.reportprogress(100);
                        };

                        //进度变化时改变进度对话框中的进度值
                        bgworker.progresschanged += delegate(object senderobj, system.componentmodel.progresschangedeventargs pcea)
                        {
                            if (pcea.progresspercentage >= 0 && pcea.progresspercentage <= 100)
                            {
                                dialog.frmprogressbar.instance.progressvalue = pcea.progresspercentage;
                            }
                        };

                        //后台重新计算过滤数据完成
                        bgworker.runworkercompleted += delegate(object senderobj, system.componentmodel.runworkercompletedeventargs rwcea)
                        {
                            dialog.frmprogressbar.instance.dispose();               //关闭进度对话框
                            refreshpane(sender, newfilterdata, null, null);        //重新刷新曲线
                        };
                        bgworker.runworkerasync();      //启动后台计算过滤数据的线程
                        dialog.frmprogressbar.instance.showdialog();        //显示进度对话框
                    }

                    #endregion
               

                #endregion
            }
            catch(exception ex)
            {
                icsharpcode.core.loggingservice<datacharthelper>.error("zgc_zoomevent is exception :" + ex.message, ex);
            }
        }

 

注：

1.首先通过refillbeginindex = (int)sender.graphpane.xaxis.scale.min和refillendindex = (int)sender.graphpane.xaxis.scale.max;获取

缩放后的开始与结束的索引。

2.然后判断开始索引是否小于0，小于0则赋值为0，结束索引是否大于数据的总个数，大于则为总个数减一。

3.然后根据缩放后的开始和结束的索引获取缩放后要填充的数据。

4.中间又夹杂着进度条的显示和是否大于设置的要显示的总个数。

5.最终将过滤后的数据重新保存，并以此去刷新曲线图。