PivotGridField 中对Unbound的列赋值（除法）--数据钻取

上一中方法（http://www.cnblogs.com/shirley-w/p/4042391.html）只能计算分子和分母均在数据区域显示的除法，用数据钻取的方法可取到在其他区域甚至visible=“false”的列值

.aspx中<Fields>内的代码：

 <dx:PivotGridField ID="field_corr" Area="DataArea" AreaIndex="0"  FieldName="诊断符合数" ValueFormat-FormatType="Numeric" Caption="诊断符合数"></dx:PivotGridField>
<dx:PivotGridField ID="field_Sum" Area="DataArea" AreaIndex="1"  FieldName="诊断总数"  Caption="诊断总数"></dx:PivotGridField>
<dx:PivotGridField ID="field_compare" Area="DataArea" AreaIndex="2"  FieldName="诊断符合率" Caption="诊断符合率"  UnboundType="Decimal"></dx:PivotGridField>

其中诊断符合率=诊断符合数/诊断总数

除法需要在后台绑定OnCustomCellDisplayText事件：OnCustomCellDisplayText="pivotGrid_CustomCellDisplayText"

.cs

 protected void pivotGrid_CustomCellDisplayText(object sender, PivotCellDisplayTextEventArgs e)//通过数据钻取对病案率的计算
         {
             if (object.ReferenceEquals(e.DataField, ASPxPGDiagnosticAccordanceRate.Fields["诊断符合率"]))
             {
                 PivotDrillDownDataSource ds = e.CreateDrillDownDataSource();
                 int corrcount = 0;
                 int Sumcount = 0;
                 for (int i = 0; i < ds.RowCount; i++)
                 {
                     PivotDrillDownDataRow row = ds[i];
                     corrcount += (int)row[field_corr];
                     Sumcount += (int)row[field_Sum];
                 }
                 if (Sumcount > 0)
                 {
                     decimal perc = (decimal) corrcount/Sumcount;
                     e.DisplayText = string.Format("{0:p}", perc);
                 }
             }
         }

此方法不但可以将计算值显示在界面上，而且将“诊断符合数”、“诊断总数”列放在筛选区或者其他区域（甚至不可见，但存在此项）均可以算出结果