HeaderFooterManager

public IPresentationHeaderFooterManager HeaderFooterManager { get; }

[C#]
using (Presentation presentation = new Presentation("presentation.ppt"))
{
    IBaseSlideHeaderFooterManager headerFooterManager = presentation.Slides[0].HeaderFooterManager;
	// Property IsFooterVisible is used for indicating that a slide footer placeholder is not present.
    if (!headerFooterManager.IsFooterVisible)
    {
		// Method SetFooterVisibility is used for making a slide footer placeholder visible.
        headerFooterManager.SetFooterVisibility(true);
    }
	// Property IsSlideNumberVisible is used for indicating that a slide page number placeholder is not present.
    if (!headerFooterManager.IsSlideNumberVisible)
    {
		// Method SetSlideNumberVisibility is used for making a slide page number placeholder visible.
        headerFooterManager.SetSlideNumberVisibility(true);
    }
	// Property IsDateTimeVisible is used for indicating that a slide date-time placeholder is not present.
    if (!headerFooterManager.IsDateTimeVisible)
    {
		// Method SetFooterVisibility is used for making a slide date-time placeholder visible.
        headerFooterManager.SetDateTimeVisibility(true);
    }
	// Method SetFooterText is used for setting text to slide footer placeholder.
    headerFooterManager.SetFooterText("Footer text");
	// Method SetDateTimeText is used for setting text to slide date-time placeholder.
    headerFooterManager.SetDateTimeText("Date and time text");
	presentation.Save("Presentation.ppt",SaveFormat.ppt);
}

[C#]
using (Presentation presentation = new Presentation("presentation.ppt"))
{
    IMasterSlideHeaderFooterManager headerFooterManager = presentation.Masters[0].HeaderFooterManager;
	// Method SetFooterAndChildFootersVisibility is used for making a master slide and all child footer placeholders visible.
    headerFooterManager.SetFooterAndChildFootersVisibility(true);
	// Method SetSlideNumberAndChildSlideNumbersVisibility is used for making a master slide and all child page number placeholders visible.
    headerFooterManager.SetSlideNumberAndChildSlideNumbersVisibility(true);
	// Method SetDateTimeAndChildDateTimesVisibility is used for making a master slide and all child date-time placeholders visible.
    headerFooterManager.SetDateTimeAndChildDateTimesVisibility(true);
	// Method SetFooterAndChildFootersText is used for setting text to master slide and all child footer placeholders.
    headerFooterManager.SetFooterAndChildFootersText("Footer text");
	// Method SetDateTimeAndChildDateTimesText is used for setting text to master slide and all child date-time placeholders.
    headerFooterManager.SetDateTimeAndChildDateTimesText("Date and time text");
}