如何在JScript.Net中听键

Question

我希望使用JScript . net捕获按键，并使用jsc.exe编译代码。那么，是否有任何等效的"addEventListener("keyDown"， keyCheck)"从FLASH actionscript。或者c++中的GetAsyncKeyState()。我要用哪个图书馆?请分享一个简单的小例子。

Answer 1

如果你正在编写一个主机应用，这里有一个简单的解决方案。

import System;
Console.Write("Press the M key... ");
var key:ConsoleKeyInfo;
while (1) {
    while (!Console.KeyAvailable) {
        System.Threading.Thread.Sleep(1);
    }
    key = Console.ReadKey(1);
    if (key.Key == ConsoleKey.M) break;
}
Console.Write("Accepted.");

阅读更多关于ConsoleKeyInfo.

---

如果您需要GetAsyncKeyState()，可以在JScript.NET中访问该方法。几天前，我遇到了一个JScript。. NET函数，通过P/Invoke公开Win32 API方法。下面是为了更简单的语法(允许传递来自API函数定义的参数)而进行的稍微修改。

import System;
import System.Reflection;
import System.Reflection.Emit;
// Invoke a Win32 P/Invoke call.
// credit: http://cx20.main.jp/blog/hello/2013/03/07/hello-win32-api-jscript-net-world/
function InvokeWin32(dllName:String, returnType:Type, methodName:String, params:Object[]) {
    var paramTypes:Type[] = new Type[params.length];
    for (var i:int in params) {
        paramTypes[i] = params[i].GetType();
    }
    // Begin to build the dynamic assembly
    var domain = AppDomain.CurrentDomain;
    var name = new System.Reflection.AssemblyName('PInvokeAssembly');
    var assembly = domain.DefineDynamicAssembly(name, AssemblyBuilderAccess.Run);
    var module = assembly.DefineDynamicModule('PInvokeModule');
    var type = module.DefineType('PInvokeType',TypeAttributes.Public
        + TypeAttributes.BeforeFieldInit);
    // Define the actual P/Invoke method
    var method = type.DefineMethod(methodName, MethodAttributes.Public
        + MethodAttributes.HideBySig + MethodAttributes.Static +
        MethodAttributes.PinvokeImpl, returnType, paramTypes);
    // Apply the P/Invoke constructor
    var ctor = System.Runtime.InteropServices.DllImportAttribute.GetConstructor(
        [System.String]
    );
    var attr = new System.Reflection.Emit.CustomAttributeBuilder(ctor, [dllName]);
    method.SetCustomAttribute(attr);
    // Create the temporary type, and invoke the method.
    var realType = type.CreateType();
    return realType.InvokeMember(methodName, BindingFlags.Public + BindingFlags.Static
        + BindingFlags.InvokeMethod, null, null, params);
}

使用这个函数，您可以使用以下语法公开Win32 DLL方法。(看到了吗?告诉过你那样更简单。)

// ShowWindowAsync(hWnd:IntPtr, nCmdShow:int);
function ShowWindowAsync(... args:Object[]):boolean {
   return InvokeWin32("user32.dll", System.Boolean, "ShowWindowAsync", args);
}
// GetWindowLong(hWnd:IntPtr, nIndex:int);
function GetWindowLong(... args:Object[]):int {
    return InvokeWin32("user32.dll", System.Int32, "GetWindowLong", args);
}
// FindWindowEx(parentHandle:IntPtr, childAfter:IntPtr,
//      lclassName:IntPtr, windowTitle:String);
function FindWindowEx(... args:Object[]):IntPtr {
    return InvokeWin32("user32.dll", System.IntPtr, "FindWindowEx", args);
}

我从未使用过GetAsyncKeyState();但因为它是一个user32.dll方法，我猜它会以同样的方式工作。

// GetAsyncKeyState(vKey:int);
function GetAsyncKeyState(... args:Object[]):short {
    return InvokeWin32("user32.dll", System.Int16, "GetAsyncKeyState", args);
}

对于一个简单的例子:

import System;               // for Console methods
import System.Windows.Forms; // for Keys object constants
Console.Write("Press the M key... ");
// while the M key is not being pressed, sleep
while (!GetAsyncKeyState(Keys.M)) {
    System.Threading.Thread.Sleep(1);
}
// flush input buffer
while (Console.KeyAvailable) Console.ReadKey(1);
Console.WriteLine("Accepted.");