Question

我需要做的是根据网格中其他字段的值计算网格中一个字段的值。我需要运行此计算在其中一个从属单元格中的值更改后，但仅当该值为有效条目时。编辑器/存储库的EditValueChanged，Validating和Validated事件都在数据发布回数据源之前发生。我想知道是否有任何我可以挂钩的事件，这将允许我在数据回发到数据源之后但在控制返回给用户之前触发此计算。

示例代码

//calculation functions
private void SetCalcROP(MyObjectt Row)
{
    //rop = m/hr
    TimeSpan ts = Row.ToTime - Row.FromTime;
    double diffDepth = Row.EndDepth - Row.StartDepth;

    if (ts.TotalHours > 0)//donot divide by 0
        Row.ROP = diffDepth / ts.TotalHours;
    else
        Row.ROP = 0;
}

private void SetCalcDeltaP(MyObject Row)
{
    Row.DeltaPress = Row.SPPOnBtm - Row.SPPOffBtm;
}

//events
private void repNumberInput_Validated(object sender, EventArgs e) //is actaully ActiveEditor_Validated
{
    if (vwDDJournal.FocusedColumn.Equals(colSPPOff) || vwDDJournal.FocusedColumn.Equals(colSPPOn))
        SetCalcDeltaP(vwDDJournal.GetFocusedRow() as MyObject);
}

private void repNumberInput_NoNulls_Validated(object sender, EventArgs e) //is actaully ActiveEditor_Validated
{
    if (vwDDJournal.FocusedColumn.Equals(colStartDepth) || vwDDJournal.FocusedColumn.Equals(colEndDepth))
        SetCalcROP(vwDDJournal.GetFocusedRow() as MyObject);
}

private void repTimeEdit_Validated(object sender, EventArgs e) //is actaully ActiveEditor_Validated
{
    SetCalcROP(vwDDJournal.GetFocusedRow() as MyObject);
}

private void repNumberInput_NoNulls_Validating(object sender, System.ComponentModel.CancelEventArgs e)
{
    TextEdit TE = sender as TextEdit;
    //null is not valid for this entry;
    if (string.IsNullOrEmpty(TE.Text))
    {
        e.Cancel = true;
        vwDDJournal.SetColumnError(vwDDJournal.FocusedColumn, "This Column may not be blank");
        return;
    }
    else
    {
        double tmp;
        if (!Double.TryParse(TE.Text, out tmp))
        {
            e.Cancel = true;
            vwDDJournal.SetColumnError(vwDDJournal.FocusedColumn, "This Column must contain a number");
            return;
        }
    }
}

private void repNumberInput_Validating(object sender, System.ComponentModel.CancelEventArgs e)
{
    TextEdit TE = sender as TextEdit;
    //null is not valid for this entry;
    if (!string.IsNullOrEmpty(TE.Text))
    {
        double tmp;
        if (!Double.TryParse(TE.Text, out tmp))
        {
            e.Cancel = true;
            vwDDJournal.SetColumnError(vwDDJournal.FocusedColumn, "This Column must contain a number");
            return;
        }
    }
}

private void repTimeEdit_Validating(object sender, System.ComponentModel.CancelEventArgs e)
{
    if (vwDDJournal.FocusedColumn.Equals(colToTime))
    {//dont bother to check from time
        //TIME TRAVEL CHECK!!!!
        DateTime FromTime = Convert.ToDateTime(vwDDJournal.GetRowCellValue(vwDDJournal.FocusedRowHandle, colFromTime));
        TimeEdit te = sender as TimeEdit;
        DateTime ToTime = Convert.ToDateTime(te.EditValue);
        if (ToTime < FromTime)
        {//TIME TRAVEL
            e.Cancel = true;
            vwDDJournal.SetColumnError(vwDDJournal.FocusedColumn, "To Time must be greater than From Time");
            return;
        }
    }
}

问题在于，无论我在何处使用，我是否使用vwDDJournal.GetRowCellValue(...)或vwDDJournal.GetFocusedRow() as MyObject，我仍然会获得旧的编辑值。

要求

我必须在运行计算之前验证输入。我必须在进行更改后立即运行计算。

Answer 1

CustomCellValue怎么样？

回发到数据源后刷新数据。

每当更新数据或更改视图时都会调用它。

Answer 2

...我需要做的是根据网格中其他字段的值计算网格中一个字段的值。

完成此任务的最佳方法是使用Unbound Columns功能。

以下示例演示了如何通过处理ColumnView.CustomUnboundColumnData事件来实现此功能：

// Provides data for the Total column.
void gridView1_CustomUnboundColumnData(object sender, CustomColumnDataEventArgs e) {
   if (e.Column.FieldName == "Total" && e.IsGetData) e.Value = 
     getTotalValue(e.ListSourceRowIndex);
}
// Returns the total amount for a specific row.
decimal getTotalValue(int listSourceRowIndex) {
    DataRow row = nwindDataSet.Tables["Order Details"].Rows[listSourceRowIndex];
    decimal unitPrice = Convert.ToDecimal(row["UnitPrice"]);
    decimal quantity = Convert.ToDecimal(row["Quantity"]);
    decimal discount = Convert.ToDecimal(row["Discount"]);
    return unitPrice * quantity * (1 - discount);
}

原始示例：How to: Add an Unbound Column Storing Arbitrary Data

您还可以使用expressions实现未绑定列的计算值：

GridColumn columnTotal = new GridColumn();
columnTotal.FieldName = "Total";
columnTotal.Caption = "Total";

columnTotal.UnboundType = DevExpress.Data.UnboundColumnType.Decimal;
columnTotal.UnboundExpression = "[Quantity] * [UnitPrice] * (1 - [Discount])";

gridView1.Columns.Add(columnTotal);

事件位于网格中ActiveEditor的DataSource更新后

2 个答案: