检查VBA代码的数字签名是否有效

Aspose.Cells允许您使用Workbook.VbaProject.IsValidSigned属性检查VBA代码的数字签名是否有效。如果签名有效，则返回true，否则返回false。当您更改VBA代码时，VBA代码的数字签名将变为无效。

在C#中检查VBA代码的数字签名是否有效

以下代码演示了使用该属性的用法，使用示例Excel文件进行测试。相同的Excel文件具有有效的签名，但当我们修改其VBA代码并保存工作簿后重新检查时，我们发现其签名已变为无效。

// For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
// The path to the documents directory.
string dataDir = RunExamples.GetDataDir(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

Workbook workbook = new Workbook(dataDir + "sampleVBAProjectSigned.xlsm");

// Signature is valid
Console.WriteLine("Is VBA Code Project Valid Signed: " + workbook.VbaProject.IsValidSigned);

// Modify the VBA Code, save the workbook then reload
// VBA Code Signature will now be invalid
string code = workbook.VbaProject.Modules[1].Codes;
code = code.Replace("Welcome to Aspose", "Welcome to Aspose.Cells");
workbook.VbaProject.Modules[1].Codes = code;

// Save
workbook.Save(dataDir + "output_out.xlsm");

// Reload
workbook = new Workbook(dataDir + "output_out.xlsm");

// Now the signature is invalid
Console.WriteLine("Is VBA Code Project Valid Signed: " + workbook.VbaProject.IsValidSigned);