（轉）C#程序開發中經常遇到的10條實用的代碼

原文地址：http://www.cnblogs.com/JamesLi2015/p/3147986.html

1 讀取操作系統和CLR的版本?

OperatingSystem os = System.Environment.OSVersion;

Console.WriteLine(“Platform: {0}”, os.Platform);

Console.WriteLine(“Service Pack: {0}”, os.ServicePack);

Console.WriteLine(“Version: {0}”, os.Version);

Console.WriteLine(“VersionString: {0}”, os.VersionString);

Console.WriteLine(“CLR Version: {0}”, System.Environment.Version);

在我的Windows 7系統中，輸出以下信息：?

Platform: Win32NT

Service Pack:

Version: 6.1.7600.0

VersionString: Microsoft Windows NT 6.1.7600.0

CLR Version: 4.0.21006.1

2 讀取CPU數量，內存容量?

可以通過Windows Management Instrumentation (WMI)提供的接口讀取所需要的信息。?

private static UInt32 CountPhysicalProcessors()

{

??? ManagementObjectSearcher objects = new ManagementObjectSearcher(

?????? “SELECT * FROM Win32_ComputerSystem”);

??? ManagementObjectCollection coll = objects.Get();

??? foreach(ManagementObject obj in coll)

?? {

?????? return (UInt32)obj[“NumberOfProcessors”];

?? }

?? return 0;

}

private static UInt64 CountPhysicalMemory()

{

? ManagementObjectSearcher objects =new ManagementObjectSearcher(

???? “SELECT * FROM Win32_PhysicalMemory”);

? ManagementObjectCollection coll = objects.Get();

? UInt64 total = 0;

? foreach (ManagementObject obj in coll)

? {

????? total += (UInt64)obj[“Capacity”];

?? }

?? return total;

}

請添加對程序集System.Management的引用，確保代碼可以正確編譯。

Console.WriteLine(“Machine: {0}”, Environment.MachineName);

Console.WriteLine(“# of processors (logical): {0}”, Environment.ProcessorCount);

Console.WriteLine(“# of processors (physical): {0}”? CountPhysicalProcessors());

Console.WriteLine(“RAM installed: {0:N0} bytes”,? CountPhysicalMemory());

Console.WriteLine(“Is OS 64-bit? {0}”,?? Environment.Is64BitOperatingSystem);

Console.WriteLine(“Is process 64-bit? {0}”,? Environment.Is64BitProcess);

Console.WriteLine(“Little-endian: {0}”, BitConverter.IsLittleEndian);

foreach (Screen screen in? System.Windows.Forms.Screen.AllScreens)

{

??? Console.WriteLine(“Screen {0}”, screen.DeviceName);

??? Console.WriteLine(“\tPrimary {0}”, screen.Primary);

??? Console.WriteLine(“\tBounds: {0}”, screen.Bounds);

??? Console.WriteLine(“\tWorking Area: {0}”,screen.WorkingArea);

??? Console.WriteLine(“\tBitsPerPixel: {0}”,screen.BitsPerPixel);

}

3 讀取注冊表鍵值對?

using (RegistryKey keyRun = Registry.LocalMachine.OpenSubKey(@”Software\Microsoft\Windows\CurrentVersion\Run”))

{

?? foreach (string valueName in keyRun.GetValueNames())

?? {

??? Console.WriteLine(“Name: {0}\tValue: {1}”, valueName, keyRun.GetValue(valueName));

?? }

請添加命名空間Microsoft.Win32，以確保上面的代碼可以編譯。

4 啟動，停止Windows服務?

這項API提供的實用功能常常用來管理應用程序中的服務，而不必到控制面板的管理服務中進行操作。?

ServiceController controller = new ServiceController(“e-M-POWER”);?????

controller.Start();?????

if (controller.CanPauseAndContinue)? ????

{?????

?? controller.Pause();?????

?? controller.Continue();?????

}?????

controller.Stop();

.net提供的API中，可以實現一句話安裝與卸載服務?

if (args[0] == "/i")

{

????? ManagedInstallerClass.InstallHelper(new string[] { Assembly.GetExecutingAssembly().Location });

}

else if (args[0] == "/u")

{

? ManagedInstallerClass.InstallHelper(new string[] { "/u", Assembly.GetExecutingAssembly().Location });

如代碼所示，給應用程序傳入i或u參數，以表示是卸載或是安裝程序。

5 驗證程序是否有strong name (P/Invoke)?

比如在程序中，為了驗證程序集是否有簽名，可調用如下方法?

[DllImport("mscoree.dll", CharSet=CharSet.Unicode)]

static extern bool StrongNameSignatureVerificationEx(string wszFilePath, bool fForceVerification, ref bool pfWasVerified);

bool notForced = false;

bool verified = StrongNameSignatureVerificationEx(assembly, false, ref notForced);

Console.WriteLine("Verified: {0}\nForced: {1}", verified, !notForced);

這個功能常用在軟件保護方法，可用來驗證簽名的組件。即使你的簽名被人去掉，或是所有程序集的簽名都被去除，只要程序中有這一項調用代碼，則可以停止程序運行。

6 響應系統配置項的變更?

比如我們鎖定系統后，如果QQ沒有退出，則它會顯示了忙碌狀態。

請添加命名空間Microsoft.Win32，然后對注冊下面的事件。?

. DisplaySettingsChanged (包含Changing) 顯示設置

. InstalledFontsChanged 字體變化

. PaletteChanged

. PowerModeChanged 電源狀態

. SessionEnded (用戶正在登出或是會話結束)

. SessionSwitch (變更當前用戶)

. TimeChanged 時間改變

. UserPreferenceChanged (用戶偏號包含Changing)

我們的ERP系統，會監測系統時間是否改變，如果將時間調整后ERP許可文件之外的范圍，會導致ERP軟件不可用。

7 運用Windows7的新特性?

Windows7系統引入一些新特性，比如打開文件對話框，狀態欄可顯示當前任務的進度。?

Microsoft.WindowsAPICodePack.Dialogs.CommonOpenFileDialog ofd = new Microsoft.WindowsAPICodePack.Dialogs.CommonOpenFileDialog();

ofd.AddToMostRecentlyUsedList = true;

ofd.IsFolderPicker = true;

ofd.AllowNonFileSystemItems = true;

ofd.ShowDialog();

用這樣的方法打開對話框，與BCL自帶類庫中的OpenFileDialog功能更多一些。不過只限于Windows 7系統中，所以要調用這段代碼，還要檢查操作系統的版本要大于6，并且添加對程序集Windows API Code Pack for Microsoft?.NET Framework的引用，請到這個地址下載 http://code.msdn.microsoft.com/WindowsAPICodePack

8 檢查程序對內存的消耗?

用下面的方法，可以檢查.NET給程序分配的內存數量?

long available = GC.GetTotalMemory(false);

Console.WriteLine(“Before allocations: {0:N0}”, available);

int allocSize = 40000000;

byte[] bigArray = new byte[allocSize];

available = GC.GetTotalMemory(false);

Console.WriteLine(“After allocations: {0:N0}”, available);

在我的系統中，它運行的結果如下所示?

Before allocations: 651,064

After allocations: 40,690,080

使用下面的方法，可以檢查當前應用程序占用的內存?

Process proc = Process.GetCurrentProcess();

Console.WriteLine(“Process Info: “+Environment.NewLine+

“Private Memory Size: {0:N0}”+Environment.NewLine +

“Virtual Memory Size: {1:N0}” + Environment.NewLine +

“Working Set Size: {2:N0}” + Environment.NewLine +

“Paged Memory Size: {3:N0}” + Environment.NewLine +

“Paged System Memory Size: {4:N0}” + Environment.NewLine +

?“Non-paged System Memory Size: {5:N0}” + Environment.NewLine,

proc.PrivateMemorySize64,?? proc.VirtualMemorySize64,? proc.WorkingSet64,? proc.PagedMemorySize64, proc.PagedSystemMemorySize64,? proc.NonpagedSystemMemorySize64 );

9 使用記秒表檢查程序運行時間?

如果你擔憂某些代碼非常耗費時間，可以用StopWatch來檢查這段代碼消耗的時間，如下面的代碼所示?

System.Diagnostics.Stopwatch timer = new System.Diagnostics.Stopwatch();

timer.Start();

Decimal total = 0;

int limit = 1000000;

for (int i = 0; i < limit; ++i)

{

???? total = total + (Decimal)Math.Sqrt(i);

}

timer.Stop();

Console.WriteLine(“Sum of sqrts: {0}”,total);