I like to share that issue shared has been resolved in Aspose.Slides for .NET 6.7.0. Please use the following code snippet to serve the purpose. We will share the notification with you once the product release will be made available on-line by today evening.
public static void chaneLabelProperty()
{
String path = @“C:\Users\Mudassir\Downloads”;
PresentationEx pres = new PresentationEx();
//Access first slide
SlideEx sld = pres.Slides[0];
// Add chart with default data
ChartEx chart = sld.Shapes.AddChart(ChartTypeEx.ClusteredBar, 0, 0, 500, 500);
//Take first chart series
ChartSeriesEx series = chart.ChartData.Series[1];
//set general params for all labels in series
series.Labels.ShowValue = true; series.Labels.TextProperties.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FillFormat.FillType = FillTypeEx.Solid; series.Labels.TextProperties.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FillFormat.SolidFillColor.
Color = Color.Yellow;
//for creation custom lables with custom text use TextFrame property
DataLabelEx lbl = new DataLabelEx(series);
lbl.Id = 0;
lbl.ShowCategoryName = true;
lbl.Separator = “/”;
lbl.TextFrame.Text = “Hi Mudassir”;
lbl.TextFrame.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FontHeight = 12;
lbl.TextFrame.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FillFormat.FillType = FillTypeEx.Solid;
lbl.TextFrame.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FillFormat.SolidFillColor.Color = Color.Red;
lbl.TextFrame.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FontBold = NullableBool.True;
series.Labels.Add(lbl);
//for creation custom lables with automatic generated data use “TextProperties”
lbl = new DataLabelEx(series);
lbl.Id = 1;
lbl.ShowValue = true;
lbl.TextProperties.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FontHeight = 44;
lbl.TextProperties.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FillFormat.FillType = FillTypeEx.Solid;
lbl.TextProperties.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FillFormat.SolidFillColor.Color = Color.Blue;
lbl.TextProperties.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FontBold = NullableBool.True;
series.Labels.Add(lbl);
// Save presentation with chart
pres.Write(path+“33468 out.pptx”);
}