是否可以在 epplus 中创建动态图表？

Question

我想知道是否可以配置 epplus 以在打开 excel 文件时单击表格数据并根据单击的表格行显示图表。 （我意识到这在 excel 中非常容易做到，我宁愿在它到达某些人之前把所有事情都处理好）

目前我只有一个数据表和每一行的图表，但如果只有一个图表会根据在 Excel 中单击的行而改变，那会更好。我也尝试了数据透视表，但这对动态图表没有帮助。

Answer 1

对于任何试图弄清楚这一点的人。我最终使用了一个数据验证下拉列表并制作了一个动态图表所基于的动态表行（在基表之外）。动态表格行根据数据验证下拉列表的值而变化（您需要对 excel 有一种感觉才能做到这一点，而我没有）：

class Program
{
    static void Main(string[] args)
    {
        // Creating an instance 
        // of ExcelPackage 
        ExcelPackage excel = new ExcelPackage();

        // name of the sheet 
        var workSheet = excel.Workbook.Worksheets.Add("testSheet");
        //init table
        var randTable = new DataTable();
        randTable.TableName = "randTable";
        //init columns
        var countColumn = new DataColumn()
        {
            DataType = typeof(int),
            ColumnName = "Count",
            ReadOnly = true,
            Unique = true
        };
        var randomColumn0 = new DataColumn()
        {
            DataType = typeof(int),
            ColumnName = "Random-0",
            ReadOnly = true,
            Unique = false
        };
        var randomColumn1 = new DataColumn()
        {
            DataType = typeof(int),
            ColumnName = "Random-1",
            ReadOnly = true,
            Unique = false
        };
        //add columns to table
        randTable.Columns.AddRange(new DataColumn[] { countColumn, randomColumn0, randomColumn1 });


        //init data validation
        ExcelRange dropdownRange = workSheet.Cells[12, 1, 12, 3];
        var dropdownValidation = workSheet.DataValidations.AddListValidation(dropdownRange.Address);
        workSheet.Names.Add("count", dropdownRange);
        //style data validation
        dropdownRange.Merge = true;
        workSheet.Cells[dropdownRange.Address].Style.Fill.PatternType = ExcelFillStyle.Solid;
        workSheet.Cells[dropdownRange.Address].Style.Fill.BackgroundColor.SetColor(Color.Yellow);
        workSheet.Cells[dropdownRange.Address].Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;

        var rand = new Random();
        for (var i = 0; i < 10; i++)
        {
            //add table first column values to validation list
            dropdownValidation.Formula.Values.Add(i.ToString());
            var row = randTable.NewRow();
            row[countColumn] = i;
            row[randomColumn0] = rand.Next(0, 100);
            row[randomColumn1] = rand.Next(0, 100);
            randTable.Rows.Add(row);
        }

        //make the tableIndexer cell. This cell will be used to get the 
        //table indices for the selected table row cells
        ExcelRange randTableIndexer = workSheet.Cells[12, 4, 12, 4];
        randTableIndexer.Formula = "MATCH(INDEX(count,1,1), randTable[Count], 0)";
        workSheet.Cells[randTableIndexer.Address].Style.Fill.PatternType = ExcelFillStyle.Solid;
        workSheet.Cells[randTableIndexer.Address].Style.Fill.BackgroundColor.SetColor(Color.LightGreen);
        workSheet.Cells[randTableIndexer.Address].Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;
        workSheet.Names.Add("tableIndex", randTableIndexer);

        //make the cells based off the table at row(randTableIndexer.value)
        ExcelRange graphCells = workSheet.Cells[13, 1, 13, 3];
        graphCells.CreateArrayFormula("INDEX(randTable[], tableIndex, 0)"); //need [] on table names in epplus formulas
        workSheet.Cells[graphCells.Address].Style.Fill.PatternType = ExcelFillStyle.Solid;
        workSheet.Cells[graphCells.Address].Style.Fill.BackgroundColor.SetColor(Color.LightBlue);
        workSheet.Cells[graphCells.Address].Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;
        graphCells.Calculate();

        //add table to workSheet
        workSheet.Cells[1, 1].LoadFromDataTable(randTable, true, OfficeOpenXml.Table.TableStyles.Medium15);
        workSheet.Cells.AutoFitColumns();


        //add dynamic chart
        var chart = workSheet.Drawings.AddChart("rands", eChartType.Pie) as ExcelPieChart;
        chart.Title.Text = "rands";
        chart.Series.Add(graphCells.Address, ExcelRange.GetAddress(1, 1, 3, 1));
        chart.Legend.Position = eLegendPosition.Bottom;
        chart.SetSize(500, 400);
        chart.SetPosition(60, 500);


        WriteToFile(excel);
    }

    public static void WriteToFile(ExcelPackage package)
    {
        // file name with .xlsx extension  
        string p_strPath = "C:\\your\\file\\path";

        if (File.Exists(p_strPath))
            File.Delete(p_strPath);

        // Create excel file on physical disk  
        FileStream objFileStrm = File.Create(p_strPath);
        objFileStrm.Close();

        // Write content to excel file  
        File.WriteAllBytes(p_strPath, package.GetAsByteArray());
    } 
}