Interop Excel Charts Exported to Image appear incomplete

Question

I am trying to export chart to image in .Net Azure functions. I referred this link. But the exported image appears incomplete.

Expected Image:

Actual Exported Image:

.Net Core 3.1 Azure Function Project

COM Reference used: Microsoft Excel 16.0 Object Library (version 1.9)

Identity: Interop.Microsoft.Office.Interop.Excel

Code:

var app = new Application();
var wkBook = app.Workbooks.Open(@"D:\MTA\Project_X.xlsx");
var wkSheet = (Worksheet)wkBook.Sheets["Overall MTA Chart"];
wkSheet.Select();
var charts = wkSheet.ChartObjects() as IEnumerable;
foreach (ChartObject item in charts)
{
    item.Select();
    var chart = (Chart)item.Chart;
    chart.Export($@"D:\MTA\{chart.Name}.png", "PNG", true);
}

Answer 1

I am not sure azure functions can support Interop.Microsoft.Office.Interop.Excel since this needs excel to be installed.

I suggest you use a different library to achieve this. (if azure functions can support, this is not the answer for you)

For an example if you use FreeSpire.XLS

var workbook = new Workbook();
workbook.LoadFromFile(workbookFileName, excel version);
var sheet = workbook.Worksheets[0];
var image = workbook.SaveChartAsImage(sheet, 0);
image.Save(chartImageFileName, ImageFormat.Png);