C#或者WPF 代码检测电脑上是否已经安装.net 4.0 环境？求解。。。
C#或者WPF 代码检测电脑上是否已经安装.net 4.0 环境？求解。。。我想要一个方法或者一个程序。在运行的机器上检测是否安装了.net 4.0 的环境。如果已经安装，返回true ，否则返回false！ C#?WPF?.net4.0? C# WPF .Net4.0 检测环境
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不知道你想要的是不是这个
http://msdn.microsoft.com/zh-cn/library/vstudio/bb909885.aspx
[解决办法]
你这有啥意义。wpf都能运行了。

方法还是有的，检查方法是看看注册表有没有相关的注册项。
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 class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("      OS Version: {0}", Environment.OSVersion);
            Console.WriteLine("     CLR Version: {0}  ( {1} )", Environment.Version, RuntimeFramework.CurrentFramework);
            Console.WriteLine("Default Encoding: {0}", Encoding.Default);
            Console.WriteLine();
            Console.WriteLine("Available Frameworks:");
            foreach (var frame in RuntimeFramework.AvailableFrameworks) Console.WriteLine("  " + frame);
            Console.ReadLine();
        }
    }

    public enum RuntimeType
    {
        Any,   // Any supported runtime framework
        Net,   // Microsoft .NET Framework 
 
        NetCF, // Microsoft .NET Compact Framework
        SSCLI, // Microsoft Shared Source CLI
        Mono,  // Mono
    }

    // See http://nunit.org, this class from NUnit Project's RuntimeFramework.cs
    // RuntimeFramework represents a particular version of a common language runtime implementation.
    [Serializable]
    public sealed class RuntimeFramework
    {
        public RuntimeType Runtime { get; private set; }
        public Version Version { get; private set; }
        public string DisplayName { get; private set; }
        static RuntimeFramework currentFramework;

        public static RuntimeFramework CurrentFramework
        {
            get
            {
                if (currentFramework == null)
                {
                    var monoRuntimeType = Type.GetType("Mono.Runtime", false);
                    var runtime = monoRuntimeType != null ? RuntimeType.Mono : RuntimeType.Net;
                    currentFramework = new RuntimeFramework(runtime, Environment.Version);
                    if (monoRuntimeType != null)
                    {
                        var method = monoRuntimeType.GetMethod("GetDisplayName", BindingFlags.Static  
 
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                          BindingFlags.NonPublic 
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 BindingFlags.DeclaredOnly 
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 BindingFlags.ExactBinding);
                        if (method != null) currentFramework.DisplayName = (string)method.Invoke(null, new object[0]);
                    }
                }
                return currentFramework;
            }
        }

        public static RuntimeFramework[] AvailableFrameworks
        {
            get
            {
                var frameworks = new List<RuntimeFramework>();
                foreach (var framework in GetAvailableFrameworks(RuntimeType.Net)) frameworks.Add(framework);
                foreach (var framework in GetAvailableFrameworks(RuntimeType.Mono)) frameworks.Add(framework);
                return frameworks.ToArray();
            }
        }

        public static bool IsMonoInstalled()
        {
            if (CurrentFramework.Runtime == RuntimeType.Mono) return true;
            // Don't know how to do this on linux yet, but it's not a problem since we are only supporting Mono on Linux 
 
            if (Environment.OSVersion.Platform != PlatformID.Win32NT) return false;
            var key = Registry.LocalMachine.OpenSubKey(@"Software\Novell\Mono");
            if (key == null) return false;
            var version = key.GetValue("DefaultCLR") as string;
            if (string.IsNullOrEmpty(version)) return false;
            return key.OpenSubKey(version) != null;
        }

        // Returns an array of all available frameworks of a given type, for example, all mono or all .NET frameworks.
        public static RuntimeFramework[] GetAvailableFrameworks(RuntimeType rt)
        {
            var frameworks = new List<RuntimeFramework>();
            if (rt == RuntimeType.Net && Environment.OSVersion.Platform != PlatformID.Unix)
            {
                var key = Registry.LocalMachine.OpenSubKey(@"Software\Microsoft\.NETFramework\policy");
                if (key != null)
                    foreach (var name in key.GetSubKeyNames())
                        if (name.StartsWith("v"))
                            foreach (var build in key.OpenSubKey(name).GetValueNames())
                                frameworks.Add(new RuntimeFramework(rt, new Version(name.Substring(1) + "." + build))); 
 
            }
            else if (rt == RuntimeType.Mono && IsMonoInstalled())
            {
                var framework = new RuntimeFramework(rt, new Version(1, 1, 4322));
                framework.DisplayName = "Mono 1.0 Profile";
                frameworks.Add(framework);
                framework = new RuntimeFramework(rt, new Version(2, 0, 50727));
                framework.DisplayName = "Mono 2.0 Profile";
                frameworks.Add(framework);
            }
            return frameworks.ToArray();
        }

        public RuntimeFramework(RuntimeType runtime, Version version)
        {
            Runtime = runtime;
            Version = version;
            DisplayName = runtime.ToString() + " " + version.ToString();
        }

        public override string ToString()
        {
            return DisplayName;
        }
    }

这个貌似满足了楼主的要求
[解决办法]
读取注册表，就可以查看了，具体路径HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\
RegistryKey rk;
rk = Registry.LocalMachine.OpenSubKey(路径);
后面的自己看属性吧
[解决办法]
简单的方法，写个代码查看安装文件里面有没有4.0.
win7 例：C:\Windows\Microsoft.NET\Framework 下查看是否有4.0

另外一个：http://blog.csdn.net/yysyangyangyangshan/article/details/7039769