[Problem/Bug]: `CoreWebView2PrintSettings.ScaleFactor` is not working for `PrintAsync` on PDF files

[Fan-iX]

What happened?

CoreWebView2PrintSettings.ScaleFactor is not working for PrintAsync on PDF pages.

Additional info:

• It works for html pages (fixed in [Problem/Bug]: CoreWebView2PrintSettings.ScaleFactor is not working when Windows's Microsoft WebView2 Runtime automatically upgade to 118.0.2088.46 verson #4091).
• It does not work for both physical (such as HP LaserJet M227) and virtual printers (such as Microsoft Print to PDF).
  • The scale factor option in the native print dialog works fine in the meantime.
• It does not work for PrintToPdfAsync either.
  • This is expected since the corresponding save as pdf option in the print dialog does not accept a scale factor.

Importance

Blocking. My app's basic functions are not working due to this issue.

Runtime Channel

Stable release (WebView2 Runtime)

Runtime Version

146.0.3856.84

SDK Version

1.0.3912.50

Framework

Winforms

Operating System

Windows 11

OS Version

26200.8037

Repro steps

1. put Program.cs and winformtest.csproj at a empty winformtest folder
2. put test.pdf at D:/ (or change the hard-coded file url in Program.cs)
3. run dotnet publish
4. launch bin\publish\winformtest.exe
5. click at Print 1 button, save the pdf as 1.pdf
6. click at Print 2 button, save the pdf as 2.pdf
7. 1.pdf and 2.pdf are basically the same. CoreWebView2PrintSettings.ScaleFactor makes no difference here.

original test.pdf

Microsoft Print to PDF 1.pdf/2.pdf

Program.cs

using System;
using System.Drawing;
using System.Windows.Forms;
using Microsoft.Web.WebView2.WinForms;
using Microsoft.Web.WebView2.Core;

public class Form1 : Form
{
    public Form1()
    {
        SuspendLayout();
        Button btn1 = new Button()
        {
            Text = "Print 1",
            Location = new Point(0, 0),
            Size = new Size(60, 30)
        };
        Button btn2 = new Button()
        {
            Text = "Print 2",
            Location = new Point(60, 0),
            Size = new Size(60, 30)
        };
        Controls.Add(btn1);
        Controls.Add(btn2);
        WebView2 wv = new WebView2()
        {
            Anchor = AnchorStyles.Left | AnchorStyles.Right | AnchorStyles.Bottom,
            Location = new Point(0, 30),
            Size = new Size(ClientSize.Width, ClientSize.Height - 30),
            Source = new Uri("file:///D:/test.pdf")
        };
        Controls.Add(wv);
        ResumeLayout(false);
        PerformLayout();
        btn1.Click += (s, e) =>
        {
            CoreWebView2PrintSettings printSettings = wv.CoreWebView2.Environment.CreatePrintSettings();
            printSettings.PrinterName = "Microsoft Print to PDF";
            printSettings.Orientation = CoreWebView2PrintOrientation.Landscape;
            printSettings.ScaleFactor = 0.5;
            printSettings.MarginLeft = printSettings.MarginRight = 0;
            printSettings.MarginTop = printSettings.MarginBottom = 0;
            wv.CoreWebView2.PrintAsync(printSettings);
        };

        btn2.Click += (s, e) =>
        {
            CoreWebView2PrintSettings printSettings = wv.CoreWebView2.Environment.CreatePrintSettings();
            printSettings.PrinterName = "Microsoft Print to PDF";
            printSettings.Orientation = CoreWebView2PrintOrientation.Landscape;
            printSettings.ScaleFactor = 2.0;
            printSettings.MarginLeft = printSettings.MarginRight = 0;
            printSettings.MarginTop = printSettings.MarginBottom = 0;
            wv.CoreWebView2.PrintAsync(printSettings);
        };
    }
}
public class Program
{
    [STAThread]
    public static void Main()
    {
        Application.Run(new Form1());
    }
}

winformtest.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <PlatformTarget>x64</PlatformTarget>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net48</TargetFramework>
    <Configuration>Release</Configuration>
    <PublishDir>bin\Publish</PublishDir>
    <UseWindowsForms>true</UseWindowsForms>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.Web.WebView2" Version="1.0.3912.50" />
  </ItemGroup>
</Project>

test.pdf

%PDF-1.7
1 0 obj
<< /Type /Catalog /Pages 2 0 R >>
endobj
2 0 obj
<< /Type /Pages /Kids [3 0 R] /Count 1 >>
endobj
3 0 obj
<< /Type /Page
   /Parent 2 0 R
   /MediaBox [0 0 595 420]
   /Contents 4 0 R
   /Resources << >>
>>
endobj
4 0 obj
<< /Length 150 >>
stream
1 0 0 rg 0 335 85 85 re f
0 1 0 rg 510 335 85 85 re f
0 0 1 rg 0 0 85 85 re f
1 1 0 rg 510 0 85 85 re f
endstream
endobj
xref
0 5
0000000000 65535 f 
0000000009 00000 n 
0000000058 00000 n 
0000000115 00000 n 
0000000223 00000 n 
trailer
<< /Size 5 /Root 1 0 R >>
startxref
423
%%EOF

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

Don't know

Last working version (if regression)

No response