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koffi 枚举所有屏幕并显示坐标 ​

koffi EnumDisplayMonitors

GitHub 代码：https://github.com/xieerduos/koffi-example/blob/main/EnumDisplayMonitors.js

通过 user32 EnumDisplayMonitors ​

EnumDisplayMonitors.js

js
// EnumDisplayMonitors
// 官方文档：https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-enumdisplaymonitors
const koffi = require("koffi");

// 加载 user32.dll
const user32 = koffi.load("user32.dll");

// 定义数据类型
const HANDLE = koffi.pointer("HANDLE", koffi.opaque());

const HDC = koffi.pointer("HDC", koffi.opaque());
const RECT = koffi.struct("RECT", {
  left: "long",
  top: "long",
  right: "long",
  bottom: "long",
});
const LPARAM = koffi.alias("LPARAM", "long");

// 定义 MONITORENUMPROC 回调函数的签名
const MonitorEnumProc = koffi.proto(
  //   "bool __stdcall MonitorEnumProc(HANDLE HMONITOR, HDC hdcMonitor, RECT* lprcMonitor, LPARAM dwData)"
  "bool __stdcall MonitorEnumProc(int32, HDC hdcMonitor, RECT* lprcMonitor, LPARAM dwData)"
);

// 声明 EnumWindows 函数，这是 user32.dll 中的一个函数，用于枚举所有顶层窗口
const EnumDisplayMonitors = user32.func(
  "__stdcall",
  "EnumDisplayMonitors",
  "bool",
  [
    HANDLE,
    HANDLE,
    koffi.pointer(MonitorEnumProc), // 回调函数的指针
    LPARAM, // 附加参数，传递给回调函数
  ]
);

// const GetMonitorInfoW = user32.func(
//   "bool __stdcall GetMonitorInfoW(int32, HANDLE lpmi)"
// );
// 定义 MONITORINFO 结构
const MONITORINFO = Buffer.alloc(40);
MONITORINFO.writeInt32LE(40, 0); // cbSize
// 枚举窗口的回调函数
const cb1 = koffi.register((hMonitor, hdcMonitor, lprcMonitor, dwData) => {
  const rect = koffi.decode(lprcMonitor, RECT);

  console.log("rect1", convertToXYWH({ rect: rect }));

  //   if (GetMonitorInfoW(hMonitor, MONITORINFO)) {
  //     const left = MONITORINFO.readInt32LE(4);
  //     const top = MONITORINFO.readInt32LE(8);
  //     const right = MONITORINFO.readInt32LE(12);
  //     const bottom = MONITORINFO.readInt32LE(16);
  //     const rect = convertToXYWH({ rect: { left, top, right, bottom } });
  //     console.log("rect2", rect);
  //   }

  console.log("Monitor handle:", hMonitor);
  console.log("Monitor lprcMonitor:", lprcMonitor);
  return true; // 返回 true 继续枚举，返回 false 停止枚举
}, koffi.pointer(MonitorEnumProc)); // 传递回调签名

console.time("EnumDisplayMonitors");
EnumDisplayMonitors(0, 0, cb1, 0);
koffi.unregister(cb1);
console.timeEnd("EnumDisplayMonitors");

function convertToXYWH({ rect, className }) {
  const newItem = {
    x: rect.left,
    y: rect.top,
    width: rect.right - rect.left,
    height: rect.bottom - rect.top,
    className,
  };
  if (!className) {
    delete newItem.className;
  }
  return newItem;
}

代码输出结果，我有两个屏幕，所以输出了两个

powershell
PS C:\Users\Administrator\Desktop\koffi-example> node .\EnumDisplayMonitors.js
rect1 { x: 0, y: 0, width: 2048, height: 1152 }
Monitor handle: 131073
Monitor lprcMonitor: [External: 229b726ffb8]
rect1 { x: 2560, y: 0, width: 1920, height: 1080 }
Monitor handle: 65592
Monitor lprcMonitor: [External: 229b726ffb8]
EnumDisplayMonitors: 2.917ms
PS C:\Users\Administrator\Desktop\koffi-example>

通过 user32 GetMonitorInfoW 根据句柄 id 获取屏幕信息 ​

js
// EnumDisplayMonitors 官方文档：https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-enumdisplaymonitors
// GetMonitorInfoW 官方文档：https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getmonitorinfow
const koffi = require("koffi");

// 加载 user32.dll
const user32 = koffi.load("user32.dll");

// 定义数据类型
const HANDLE = koffi.pointer("HANDLE", koffi.opaque());

const HDC = koffi.pointer("HDC", koffi.opaque());
const RECT = koffi.struct("RECT", {
  left: "long",
  top: "long",
  right: "long",
  bottom: "long",
});
const LPARAM = koffi.alias("LPARAM", "long");

// 定义 MONITORENUMPROC 回调函数的签名
const MonitorEnumProc = koffi.proto(
  //   "bool __stdcall MonitorEnumProc(HANDLE HMONITOR, HDC hdcMonitor, RECT* lprcMonitor, LPARAM dwData)"
  "bool __stdcall MonitorEnumProc(int32, HDC hdcMonitor, RECT* lprcMonitor, LPARAM dwData)"
);

// 声明 EnumWindows 函数，这是 user32.dll 中的一个函数，用于枚举所有顶层窗口
const EnumDisplayMonitors = user32.func(
  "__stdcall",
  "EnumDisplayMonitors",
  "bool",
  [
    HANDLE,
    HANDLE,
    koffi.pointer(MonitorEnumProc), // 回调函数的指针
    LPARAM, // 附加参数，传递给回调函数
  ]
);

const GetMonitorInfoW = user32.func( 
  "bool __stdcall GetMonitorInfoW(int32, HANDLE lpmi)"
); 
// 定义 MONITORINFO 结构
const MONITORINFO = Buffer.alloc(40); 
MONITORINFO.writeInt32LE(40, 0); // cbSize
// 枚举窗口的回调函数
const cb1 = koffi.register((hMonitor, hdcMonitor, lprcMonitor, dwData) => {
  // const rect = koffi.decode(lprcMonitor, RECT);

  // console.log("rect1", convertToXYWH({ rect: rect }));

  if (GetMonitorInfoW(hMonitor, MONITORINFO)) { 
    const left = MONITORINFO.readInt32LE(4); 
    const top = MONITORINFO.readInt32LE(8); 
    const right = MONITORINFO.readInt32LE(12); 
    const bottom = MONITORINFO.readInt32LE(16); 
    const rect = convertToXYWH({ rect: { left, top, right, bottom } }); 
    console.log("rect2", rect); 
  } 

  console.log("Monitor handle:", hMonitor);
  console.log("Monitor lprcMonitor:", lprcMonitor);
  return true; // 返回 true 继续枚举，返回 false 停止枚举
}, koffi.pointer(MonitorEnumProc)); // 传递回调签名

console.time("EnumDisplayMonitors");
EnumDisplayMonitors(0, 0, cb1, 0);
koffi.unregister(cb1);
console.timeEnd("EnumDisplayMonitors");

function convertToXYWH({ rect, className }) {
  const newItem = {
    x: rect.left,
    y: rect.top,
    width: rect.right - rect.left,
    height: rect.bottom - rect.top,
    className,
  };
  if (!className) {
    delete newItem.className;
  }
  return newItem;
}

输出结果

powershell
PS C:\Users\Administrator\Desktop\koffi-example> node EnumDisplayMonitors.js
rect2 { x: 0, y: 0, width: 2048, height: 1152 }
Monitor handle: 131073
Monitor lprcMonitor: [External: 1bda348ffb8]
rect2 { x: 2560, y: 0, width: 1920, height: 1080 }
Monitor handle: 65592
Monitor lprcMonitor: [External: 1bda348ffb8]
EnumDisplayMonitors: 3.291ms
PS C:\Users\Administrator\Desktop\koffi-example>

综合例子 ​

增加判断是否为主显示器、获取工作区

js
// EnumDisplayMonitors
// 官方文档：https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-enumdisplaymonitors
const koffi = require("koffi");

// 加载 user32.dll
const user32 = koffi.load("user32.dll");

// 定义数据类型
const HANDLE = koffi.pointer("HANDLE", koffi.opaque());

const HDC = koffi.pointer("HDC", koffi.opaque());
const RECT = koffi.struct("RECT", {
  left: "long",
  top: "long",
  right: "long",
  bottom: "long",
});
const LPARAM = koffi.alias("LPARAM", "long");

// 定义 MONITORINFO 结构
const MONITORINFO = Buffer.alloc(40); 
MONITORINFO.writeInt32LE(40, 0); // cbSize
const MONITORINFOF_PRIMARY = 0x00000001; 

// 定义 MONITORENUMPROC 回调函数的签名
const MonitorEnumProc = koffi.proto(
  //   "bool __stdcall MonitorEnumProc(HANDLE HMONITOR, HDC hdcMonitor, RECT* lprcMonitor, LPARAM dwData)"
  "bool __stdcall MonitorEnumProc(int32, HDC hdcMonitor, RECT* lprcMonitor, LPARAM dwData)"
);

// 声明 EnumWindows 函数，这是 user32.dll 中的一个函数，用于枚举所有顶层窗口
const EnumDisplayMonitors = user32.func(
  "__stdcall",
  "EnumDisplayMonitors",
  "bool",
  [
    HANDLE,
    HANDLE,
    koffi.pointer(MonitorEnumProc), // 回调函数的指针
    LPARAM, // 附加参数，传递给回调函数
  ]
);

const GetMonitorInfoW = user32.func(
  "bool __stdcall GetMonitorInfoW(int32, HANDLE lpmi)"
);

const monitors = []; 
// 枚举窗口的回调函数
const cb1 = koffi.register((hMonitor, hdcMonitor, lprcMonitor, dwData) => {
  // const rect = koffi.decode(lprcMonitor, RECT);
  // console.log("rect1", convertToXYWH({ rect: rect }));
  if (GetMonitorInfoW(hMonitor, MONITORINFO)) {
    const left = MONITORINFO.readInt32LE(4);
    const top = MONITORINFO.readInt32LE(8);
    const right = MONITORINFO.readInt32LE(12);
    const bottom = MONITORINFO.readInt32LE(16);
    const rect = convertToXYWH({ rect: { left, top, right, bottom } });
    console.log("rect2", rect);

    // 判断是否为主显示器
    // #region isPrimaryMonitor
    const dwFlags = MONITORINFO.readInt32LE(36);  
    const isPrimaryMonitor = (dwFlags & MONITORINFOF_PRIMARY) !== 0;  
    console.log("isPrimaryMonitor", isPrimaryMonitor);  
    // #endregion isPrimaryMonitor
    // 获取工作区
    // #region workArea
    const workArea = {};  
    workArea.left = MONITORINFO.readInt32LE(20);  
    workArea.top = MONITORINFO.readInt32LE(24);  
    workArea.right = MONITORINFO.readInt32LE(28);  
    workArea.bottom = MONITORINFO.readInt32LE(32);  
    console.log("workArea", convertToXYWH({ rect: workArea }));  
    // #endregion workArea
    monitors.push({  
      ...rect,  
      isPrimaryMonitor,  
      workArea,  
    });  
  }

  console.log("Monitor handle:", hMonitor);
  console.log("Monitor lprcMonitor:", lprcMonitor);
  return true; // 返回 true 继续枚举，返回 false 停止枚举
}, koffi.pointer(MonitorEnumProc)); // 传递回调签名

function convertToXYWH({ rect, className }) {
  const newItem = {
    x: rect.left,
    y: rect.top,
    width: rect.right - rect.left,
    height: rect.bottom - rect.top,
    className,
  };
  if (!className) {
    delete newItem.className;
  }
  return newItem;
}

console.time("EnumDisplayMonitors");
EnumDisplayMonitors(0, 0, cb1, 0);
koffi.unregister(cb1);
console.timeEnd("EnumDisplayMonitors");

console.log("monitors", monitors);

运行结果

powershell
PS C:\Users\Administrator\Desktop\koffi-example> node EnumDisplayMonitors.js
rect2 { x: 0, y: 0, width: 2048, height: 1152 }
isPrimaryMonitor true
workArea { x: 0, y: 0, width: 2048, height: 1104 }
Monitor handle: 131073
Monitor lprcMonitor: [External: 2b6cfa9ffb8]
rect2 { x: 2560, y: 0, width: 1920, height: 1080 }
isPrimaryMonitor false
workArea { x: 2560, y: 0, width: 1920, height: 1032 }
Monitor handle: 65592
Monitor lprcMonitor: [External: 2b6cfa9ffb8]
EnumDisplayMonitors: 3.43ms
monitors [
  {
    x: 0,
    y: 0,
    width: 2048,
    height: 1152,
    isPrimaryMonitor: true,
    workArea: { left: 0, top: 0, right: 2048, bottom: 1104 }
  },
  {
    x: 2560,
    y: 0,
    width: 1920,
    height: 1080,
    isPrimaryMonitor: false,
    workArea: { left: 2560, top: 0, right: 4480, bottom: 1032 }
  }
]
PS C:\Users\Administrator\Desktop\koffi-example>