aspose.CAD. 25.10.1 DWG转PDF时，提示错误

PangXiaogang · November 4, 2025, 9:00am

A11.dwg.zip (8.6 MB)
错误日志如下：

Aspose.CAD.CadExceptions.ImageLoadException
HResult=0x80131500
Message=Drawing loading failed: Cannot process loading further due to incorrect file format structure. Error details: 给定关键字不在字典中。
Source=Aspose.CAD
StackTrace:
在 Aspose.CAD.Image.#=z4irEtv6UsN7Y(StreamContainer #=zAFU8HM$ZH4Y8, LoadOptions #=zzwR9DjTDR_Nc)
在 Aspose.CAD.Image.Load(String filePath)
在 WindowsFormsApp4.Form1.dwg2pdf(String infile) 在 C:\Users\Administrator\source\repos\WindowsFormsApp4\WindowsFormsApp4\Form1.cs 中: 第 38 行
在 WindowsFormsApp4.Form1.button1_Click(Object sender, EventArgs e) 在 C:\Users\Administrator\source\repos\WindowsFormsApp4\WindowsFormsApp4\Form1.cs 中: 第 29 行
在 System.Windows.Forms.Control.OnClick(EventArgs e)
在 System.Windows.Forms.Button.OnClick(EventArgs e)
在 System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
在 System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
在 System.Windows.Forms.Control.WndProc(Message& m)
在 System.Windows.Forms.ButtonBase.WndProc(Message& m)
在 System.Windows.Forms.Button.WndProc(Message& m)
在 System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
在 System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
在 System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
在 System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
在 System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
在 System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
在 System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
在 System.Windows.Forms.Application.Run(Form mainForm)
在 WindowsFormsApp4.Program.Main() 在 C:\Users\Administrator\source\repos\WindowsFormsApp4\WindowsFormsApp4\Program.cs 中: 第 19 行

内部异常 1:
Exception: Cannot process loading further due to incorrect file format structure. Error details: 给定关键字不在字典中。

Professionalize.Discourse · November 4, 2025, 9:02am

@PangXiaogang

Why the exception is thrown

ImageLoadException : “给定关键字不在字典中” is raised by Aspose.CAD when the library cannot recognise a keyword in the DWG file header. This usually happens for one (or more) of the following reasons:

Reason	What it means	How to resolve it
Corrupted or incomplete file	The binary data does not match any known DWG structure.	Open the file in AutoCAD (or another DWG viewer). If it opens, re‑save it; if it does not, obtain a clean copy.
DWG version newer than the library supports	Aspose.CAD 25.10.1 supports DWG up to the 2022 release. Newer versions (2023, 2024…) contain keywords the library does not know.	Re‑save the drawing in an older AutoCAD version (DWG 2022 or earlier) or upgrade to a newer Aspose.CAD build that adds support for the newer version.
Wrong file inside the archive	macOS archives often contain a `__MACOSX/._YourFile.dwg` resource‑fork entry. Loading that file fails.	Extract the archive and use the real `YourFile.dwg` (ignore the `__MACOSX` folder).
Missing/incorrect load options (rare)	Some DWG files need the loader to be forced to a specific version.	Use `CadLoadOptions` and, if required, set `LoadVersion`.

Step‑by‑step solution

1. Extract the DWG correctly

# PowerShell example
Expand-Archive -Path "C:\Temp\A11.dwg.zip" -DestinationPath "C:\Temp\A11_extracted"

Verify that C:\Temp\A11_extracted\A11.dwg exists and that you are not using any file from the __MACOSX sub‑folder.

2. (Optional) Check the DWG version

Open the file in AutoCAD → File → Properties → DWG version.
If the version is newer than 2022, re‑save it as an older version or upgrade Aspose.CAD.

3. Convert the DWG to PDF with Aspose.CAD

using Aspose.CAD;
using Aspose.CAD.ImageOptions;
using Aspose.CAD.LoadOptions;

string dwgPath = @"C:\Temp\A11_extracted\A11.dwg";

// -----------------------------------------------------------------
// Load options – only needed if you must force a specific version.
// -----------------------------------------------------------------
var loadOptions = new CadLoadOptions
{
    // Example (uncomment if required):
    // LoadVersion = CadVersion.Dwg2022
};

// -----------------------------------------------------------------
// Load the drawing
// -----------------------------------------------------------------
using (Image cadImage = Image.Load(dwgPath, loadOptions))
{
    // -----------------------------------------------------------------
    // PDF export options
    // -----------------------------------------------------------------
    var pdfOptions = new PdfOptions
    {
        // Rasterize the vector drawing at the desired DPI.
        // The property name is VectorRasterizationOptions.
        VectorRasterizationOptions = new CadRasterizationOptions
        {
            Dpi = 300,                     // adjust as needed
            PageSize = CadPageSize.A4,     // or any other size
            // You can also set BackgroundColor, Layout, etc.
        }
    };

    string pdfPath = @"C:\Temp\A11.pdf";
    cadImage.Save(pdfPath, pdfOptions);
}

What the code does

Loads the DWG with optional CadLoadOptions.
Creates PdfOptions and assigns a CadRasterizationOptions object to VectorRasterizationOptions (this controls DPI, page size, background colour, etc.).
Saves the image as a PDF.

4. If the same exception persists

The DWG is either corrupted or from a newer version that the current Aspose.CAD build cannot parse.
Obtain a clean copy of the file or upgrade to the latest Aspose.CAD release (download from the official Aspose site and replace the DLLs).

5. Verify the output

Open C:\Temp\A11.pdf in any PDF viewer to confirm that the conversion succeeded.

Quick checklist

[ ] Extract the archive and use the real A11.dwg (ignore __MACOSX files).
[ ] If the DWG version is newer than 2022, re‑save it in an older version or upgrade Aspose.CAD.
[ ] Load with Image.Load(dwgPath, new CadLoadOptions()) (set LoadVersion only when needed).
[ ] Export using PdfOptions with VectorRasterizationOptions = new CadRasterizationOptions { … }.
[ ] If the error remains, obtain a clean DWG copy or use a newer Aspose.CAD version.

Feel free to let me know the exact DWG version (e.g., “DWG 2023”) if you need guidance on which Aspose.CAD build adds support for it.

oleksii.gorokhovatskyi · November 4, 2025, 12:35pm

@PangXiaogang,
您好，
感谢您提供的详细信息，我们已经重现了该问题，并创建了 CADJAVA-12043 来修复它。