public class TGAFormat : ExportFormat 

//This example demonstrates how to export a layout to TGA.

//Added references
using ArcGIS.Desktop.Core;                         //Project
using ArcGIS.Desktop.Layouts;                      //Layout classes
using ArcGIS.Desktop.Framework.Threading.Tasks;    //QueuedTask
using ArcGIS.Desktop.Mapping;                      //Export formats

public class ExportLayoutToTGAExample
{
  public static Task ExportLayoutToTGAAsync(string LayoutName, string Path)
  {
    //Reference a layoutitem in a project by name
    LayoutProjectItem layoutItem = Project.Current.GetItems<LayoutProjectItem>().FirstOrDefault(item => item.Name.Equals(LayoutName));
    if (layoutItem == null)
      return Task.FromResult<Layout>(null);

    //Create TGA format with appropriate settings
    TGAFormat TGA = new TGAFormat();
    TGA.Resolution = 300;
    TGA.OutputFileName = Path;

    return QueuedTask.Run(() =>
    {
            //Export Layout
            Layout lyt = layoutItem.GetLayout(); //Loads and returns the layout associated with a LayoutItem
            if (TGA.ValidateOutputFilePath())
      {
        lyt.Export(TGA);
      }
    });
  }
}

//This example demonstrates how to export an individual map frame on a layout to TGA.

//Added references
using ArcGIS.Desktop.Core;                         //Project
using ArcGIS.Desktop.Layouts;                      //Layout classes
using ArcGIS.Desktop.Framework.Threading.Tasks;    //QueuedTask
using ArcGIS.Desktop.Mapping;                      //Export formats

public class ExportMapFrameToTGAExample
{
  public static Task ExportMapFrameToTGAAsync(string LayoutName, string MFName, string Path)
  {
    //Reference a layoutitem in a project by name
    LayoutProjectItem layoutItem = Project.Current.GetItems<LayoutProjectItem>().FirstOrDefault(item => item.Name.Equals(LayoutName));
    if (layoutItem == null)
      return Task.FromResult<Layout>(null);

    //Create TGA format with appropriate settings
    TGAFormat TGA = new TGAFormat();
    TGA.Resolution = 300;
    TGA.OutputFileName = Path;

    return QueuedTask.Run(() =>
    {
            //Export MapFrame
            Layout lyt = layoutItem.GetLayout(); //Loads and returns the layout associated with a LayoutItem
            MapFrame mf = lyt.FindElement(MFName) as MapFrame;
      TGA.OutputFileName = Path;
      if (TGA.ValidateOutputFilePath())
      {
        mf.Export(TGA);
      }
    });
  }
}

//This example demonstrates how to export the active mapview to TGA.

//Added references
using ArcGIS.Desktop.Framework.Threading.Tasks;    //QueuedTask
using ArcGIS.Desktop.Mapping;                      //MapView and Export formats

public class ExportActiveMapToTGAExample
{
  public static Task ExportActiveMapToTGAAsync(string Path)
  {
    return QueuedTask.Run(() =>
    {
            //Reference the active map view
            MapView mapv = MapView.Active;

            //Create TGA format with appropriate settings
            TGAFormat TGA = new TGAFormat();
      TGA.Resolution = 300;
      TGA.Height = 500;
      TGA.Width = 800;
      TGA.OutputFileName = Path;

            //Export active map view
            if (TGA.ValidateOutputFilePath())
      {
        mapv.Export(TGA);
      }
    });
  }
}

TGAFormat TGA = new TGAFormat();