search
HomeBackend DevelopmentC#.Net TutorialUse VS2010 C# to develop ActiveX controls (Part 2), complete code package download

In fact, if we do not set it up, but just modify the code, after running the program, the error interface will be as shown in Figure 1 below:

使用VS2010 C#开发ActiveX控件(下),完整代码打包下载

The exception thrown is as follows:

************** Exception Text **************

System.MethodAccessException: Attempt by security transparent method ' Rare.Card.Libary.Controls.

ReadCardControl.btnRead_Click(System.Object, System.EventArgs)' to call native code through method 'Rare.Card.Libary.MifareOneHelper.rf_read(Int32, Int32, Byte[ ])' failed. Methods must be security critical or

security safe-critical to call native code.

By consulting MSDN, the explanation of the exception is as follows:

In Microsoft .NET Framework 4, the common language runtime (CLR) security model has undergone many changes. One of the changes, the adoption of Level2 transparency (very similar to Silverlight's security model) is likely to affect the authors of the AllowPartiallyTrustedCallers (APTCA) library. There are three transparency attributes: SecurityTransparent, SecuritySafeCritical and SecurityCritical.

SecurityTransparent: Code marked as SecurityTransparent is reliable from a security perspective. It cannot accomplish any dangerous operations, such as asserting permissions,

executing unverifiable code, or calling native code. It also cannot call SecurityCritical code directly.

As mentioned above, for security reasons, all partially trusted code is forced to be SecurityTransparent. This is also the default transparency of the APTCA library.

SecurityCritical: Unlike SecurityTransparent, SecurityCritical code is able to perform any desired operation. It can perform declarations,

calls to native code, and other operations. It can call other methods without being restricted by the transparency flag.

Only fully trusted code can be SecurityCritical. In fact, (non-APTCA) fully trusted code is SecurityCritical by default,

thereby protecting it from calls by transparent partially trusted callers.

SecuritySafeCritical: SecuritySafeCritical code plays the role of a bridge, which allows transparent code to call key methods. SecuritySafeCritical

code has the same permissions as SecurityCritical code, but it can be called by SecurityTransparent code. Therefore, it is extremely important that SecuritySafeCritical code exposes the underlying SecurityCritical methods in a secure manner (to avoid some partially trusted malicious code trying to attack these methods through the SecuritySafeCritical layer).

Like SecurityCritical code, SecuritySafeCritical code must be fully trusted.

According to MSDN's explanation, the problem lies in the C# class library CardReader.Library that encapsulates the original Dll. We can set the transparency attribute at the code level to solve the problem.

The specific solution is as follows:

1. Set the transparent attribute of the ActiveX control card reading code to: SecuritySafeCritical. The code list after setting is as follows:

[SecuritySafeCritical] 
/// <summary> 
/// 读卡 
/// </summary> 
/// <param name="sender"></param> 
/// <param name="e"></param> 
private void btnRead_Click(object sender, EventArgs e) 
{ 
int i = 0; 
byte[] data = new byte[16]; 
byte[] buff = new byte[32]; 

for (i = 0; i < 16; i++) 
data[i] = 0; 
for (i = 0; i < 32; i++) 
buff[i] = 0; 

st = MifareOneHelper.rf_read(icdev, sec * 4 + 1, data); 
if (st == 0) 
{ 
SerialInterfaceHelper.hex_a(data, buff, 16); 
txtCardID.Text = System.Text.Encoding.ASCII.GetString(buff); 
lblMsg.Text = "读取卡号成功!"; 
} 
else 
lblMsg.Text = "读取卡号失败!"; 

//test method 
//if (string.IsNullOrEmpty(txtCardID.Text)) 
//{ 
// lblMsg.Text = "读取数据失败!"; 
//} 
//else 
//{ 
// lblMsg.Text = string.Format("读取数据:{0}!", txtCardID.Text); 
//} 
}

Be careful to add a reference: using System .Security;

The test code is commented out here, and the serial communication and card reading code are used.

2. Set the transparent attribute that encapsulates the original card reader Dll.
Set the transparent attribute of the M1 card reader helper class MifareOneHelper to: [SecurityCritical], and set the
transparent attribute of the called method MifareOneHelper.rf_read to [SecurityCritical].
Set the transparent attribute of the serial communication helper class SerialInterfaceHelper to: [SecurityCritical], and set the
transparent attribute of the called method SerialInterfaceHelper.hex_a to [SecurityCritical].

The complete code has been provided. There are two other things to note. If the client fails to install ActiveX, the address running ActiveX will be added to the trusted site.
The security level of the trusted site will be reduced to Minimize or set the Trust Sites option regarding ActiveX.

More on using VS2010 C# to develop ActiveX controls (Part 2), complete code package downloads, please pay attention to the PHP Chinese website for related articles!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
C# .NET: An Introduction to the Powerful Programming LanguageC# .NET: An Introduction to the Powerful Programming LanguageApr 22, 2025 am 12:04 AM

The combination of C# and .NET provides developers with a powerful programming environment. 1) C# supports polymorphism and asynchronous programming, 2) .NET provides cross-platform capabilities and concurrent processing mechanisms, which makes them widely used in desktop, web and mobile application development.

.NET Framework vs. C#: Decoding the Terminology.NET Framework vs. C#: Decoding the TerminologyApr 21, 2025 am 12:05 AM

.NETFramework is a software framework, and C# is a programming language. 1..NETFramework provides libraries and services, supporting desktop, web and mobile application development. 2.C# is designed for .NETFramework and supports modern programming functions. 3..NETFramework manages code execution through CLR, and the C# code is compiled into IL and runs by CLR. 4. Use .NETFramework to quickly develop applications, and C# provides advanced functions such as LINQ. 5. Common errors include type conversion and asynchronous programming deadlocks. VisualStudio tools are required for debugging.

Demystifying C# .NET: An Overview for BeginnersDemystifying C# .NET: An Overview for BeginnersApr 20, 2025 am 12:11 AM

C# is a modern, object-oriented programming language developed by Microsoft, and .NET is a development framework provided by Microsoft. C# combines the performance of C and the simplicity of Java, and is suitable for building various applications. The .NET framework supports multiple languages, provides garbage collection mechanisms, and simplifies memory management.

C# and the .NET Runtime: How They Work TogetherC# and the .NET Runtime: How They Work TogetherApr 19, 2025 am 12:04 AM

C# and .NET runtime work closely together to empower developers to efficient, powerful and cross-platform development capabilities. 1) C# is a type-safe and object-oriented programming language designed to integrate seamlessly with the .NET framework. 2) The .NET runtime manages the execution of C# code, provides garbage collection, type safety and other services, and ensures efficient and cross-platform operation.

C# .NET Development: A Beginner's Guide to Getting StartedC# .NET Development: A Beginner's Guide to Getting StartedApr 18, 2025 am 12:17 AM

To start C#.NET development, you need to: 1. Understand the basic knowledge of C# and the core concepts of the .NET framework; 2. Master the basic concepts of variables, data types, control structures, functions and classes; 3. Learn advanced features of C#, such as LINQ and asynchronous programming; 4. Be familiar with debugging techniques and performance optimization methods for common errors. With these steps, you can gradually penetrate the world of C#.NET and write efficient applications.

C# and .NET: Understanding the Relationship Between the TwoC# and .NET: Understanding the Relationship Between the TwoApr 17, 2025 am 12:07 AM

The relationship between C# and .NET is inseparable, but they are not the same thing. C# is a programming language, while .NET is a development platform. C# is used to write code, compile into .NET's intermediate language (IL), and executed by the .NET runtime (CLR).

The Continued Relevance of C# .NET: A Look at Current UsageThe Continued Relevance of C# .NET: A Look at Current UsageApr 16, 2025 am 12:07 AM

C#.NET is still important because it provides powerful tools and libraries that support multiple application development. 1) C# combines .NET framework to make development efficient and convenient. 2) C#'s type safety and garbage collection mechanism enhance its advantages. 3) .NET provides a cross-platform running environment and rich APIs, improving development flexibility.

From Web to Desktop: The Versatility of C# .NETFrom Web to Desktop: The Versatility of C# .NETApr 15, 2025 am 12:07 AM

C#.NETisversatileforbothwebanddesktopdevelopment.1)Forweb,useASP.NETfordynamicapplications.2)Fordesktop,employWindowsFormsorWPFforrichinterfaces.3)UseXamarinforcross-platformdevelopment,enablingcodesharingacrossWindows,macOS,Linux,andmobiledevices.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SecLists

SecLists

SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

VSCode Windows 64-bit Download

VSCode Windows 64-bit Download

A free and powerful IDE editor launched by Microsoft

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

MantisBT

MantisBT

Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.