调用Windows API来实现一些.NET框架本身不直接支持的功能

cs 复制代码
	public static class ModifyProgressBarColor
	{
		[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
		static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr w, IntPtr l);

		//Note the second parameter in SetState, 1 = normal (green); 2 = error (red); 3 = warning (yellow).
		public static void SetState(this System.Windows.Forms.ProgressBar pBar, int state)
		{
			SendMessage(pBar.Handle, 1040, (IntPtr)state, IntPtr.Zero);
		}
	}

	class WinAPI
	{


		//SetThreadExecutionState
		//The .NET framework classes don't provide a way to disable the screensaver or sleep mode, so we need to use Platform Invocation Services (P/Invoke) to call a Windows API function named, "SetThreadExecutionState". This function tells the operating system that the thread is in use, even if the user is not interacting with the computer. This can prevent the display from being hidden and stop the machine from being suspended automatically.
		//SetThreadExecutionState uses a series of flags to specify a new state for the current thread. We'll define these flags shortly using an enumeration with the Flags attribute. You can use the logical OR operator to combine several flags and specify multiple behaviours with a single call. The function returns a value made up from the same flags. The return value indicates the state before the changes that you requested, or returns null if there is an error.
		//The four flags that we are interested in are:
		//ES_DISPLAY_REQUIRED. This flag indicates that the display is in use. When passed by itself, the display idle timer is reset to zero once. The timer restarts and the screensaver will be displayed when it next expires.
		//ES_SYSTEM_REQUIRED. This flag indicates that the system is active. When passed alone, the system idle timer is reset to zero once. The timer restarts and the machine will sleep when it expires.
		//ES_CONTINUOUS. This flag is used to specify that the behaviour of the two previous flags is continuous. Rather than resetting the idle timers once, they are disabled until you specify otherwise. Using this flag means that you do not need to call SetThreadExecutionState repeatedly.
		//ES_AWAYMODE_REQUIRED. This flag must be combined with ES_CONTINUOUS. If the machine is configured to allow it, this indicates that the thread requires away mode. When in away mode the computer will appear to sleep as normal. However, the thread will continue to execute even though the computer has partially suspended. As this flag gives the false impression that the computer is in a low power state, you should only use it when absolutely necessary.


		[DllImport("kernel32.dll", CharSet = CharSet.Auto,SetLastError = true)]
		private static extern EXECUTION_STATE SetThreadExecutionState(EXECUTION_STATE esFlags);

		[FlagsAttribute]
		private enum EXECUTION_STATE :uint
		{
			 ES_AWAYMODE_REQUIRED = 0x00000040,
			 ES_CONTINUOUS = 0x80000000,
			 ES_DISPLAY_REQUIRED = 0x00000002,
			 ES_SYSTEM_REQUIRED = 0x00000001
			 // Legacy flag, should not be used.
			 // ES_USER_PRESENT = 0x00000004
		}

		public static void SignalActvity()
		{
			try{SetThreadExecutionState(EXECUTION_STATE.ES_CONTINUOUS | EXECUTION_STATE.ES_SYSTEM_REQUIRED | EXECUTION_STATE.ES_AWAYMODE_REQUIRED);}
			catch { }
		}

		// Clear EXECUTION_STATE flags to disable away mode and allow the system to idle to sleep normally.
		public static void SignalFree()
		{
			try{SetThreadExecutionState(EXECUTION_STATE.ES_CONTINUOUS);}
			catch { }
		}



	}

这段代码主要包含两个部分的功能:

修改进度条颜色:

通过调用Windows API函数SendMessage来改变ProgressBar控件的状态,从而改变其颜色。

SetState方法接受一个ProgressBar对象和一个状态值作为参数,状态值1表示正常(绿色),2表示错误(红色),3表示警告(黄色)。

阻止系统进入睡眠模式:

使用SetThreadExecutionState API函数来阻止系统进入睡眠模式或关闭显示器。

SignalActvity方法通过设置特定的标志来告诉系统当前线程正在使用,从而阻止系统进入睡眠模式。

SignalFree方法则清除这些标志,允许系统正常进入睡眠模式。

这段代码展示了如何使用P/Invoke技术调用Windows API来实现一些.NET框架本身不直接支持的功能。

相关推荐
默默无名的大学生10 小时前
数据结构—顺序表
数据结构·windows
湖南馒头11 小时前
【Win11 启动项BCD文件修复教程】
windows·系统恢复·win1
Tiger_shl15 小时前
【.Net技术栈梳理】05-gRPC
.net
帅得不敢出门16 小时前
macOS苹果电脑运行向日葵远程控制软件闪退
windows·macos·远程控制·向日葵
忧郁的蛋~17 小时前
使用.NET标准库实现多任务并行处理的详细过程
开发语言·c#·.net
sun032218 小时前
使用 javax.net.ssl.HttpsURLConnection 发送 HTTP 请求_以及为了JWT通信选用OSS的Jar的【坑】
http·.net·ssl
索迪迈科技21 小时前
记一次 .NET 某中医药附属医院门诊系统 崩溃分析
windows·c#·.net·windbg
十八旬21 小时前
苍穹外卖项目实战(day7-2)-购物车操作功能完善-记录实战教程、问题的解决方法以及完整代码
java·开发语言·windows·spring boot·mysql
ChaITSimpleLove1 天前
零代码入侵:Kubernetes 部署时自动注入 kube-system UID 到 .NET 9 环境变量
kubernetes·.net·环境变量·uid·kube-system·集群环境唯一id
小码编匠1 天前
WPF 多线程更新UI的两种实用方案
后端·c#·.net