需要使用 C# 刷新 chrome 浏览器

Question

在单击按钮时的 Windows 应用程序中，我需要刷新所有打开的 Chrome 浏览器实例，或者至少刷新我机器上的“活动”选项卡。

我的代码如下：

 [DllImport("user32.dll")]
 static extern bool PostMessage(IntPtr hWnd, UInt32 Msg, int wParam, int lParam);
 private void btnGetBrowserProcess_Click(object sender, EventArgs e)
    {
       const UInt32 WM_KEYDOWN = 0x0100;
       const int VK_F5 = 0x74;

        Process[] procsChrome = Process.GetProcessesByName("chrome");
        foreach (Process chrome in procsChrome)
        {
            if (chrome.MainWindowHandle != IntPtr.Zero)
            {
               PostMessage(chrome.MainWindowHandle, WM_KEYDOWN, VK_F5, 0);
            }
        }
}

这适用于 IE 和 Mozilla，但不适用于 Chrome

Answer 1

尝试改用SendInput 命令。不幸的是，这意味着您需要添加更多代码来进行设置，并且您还需要在发送按键之前将焦点设置在 chrome 窗口上。

两个必需的外部函数是：

    [DllImport("user32.dll")]
    static extern bool SetForegroundWindow(IntPtr hWnd);

    [DllImport("user32.dll", SetLastError = true)]
    private static extern uint SendInput(uint numberOfInputs, INPUT[] inputs, int sizeOfInputStructure);

那么需要的structs是：

    /// <summary>
    /// http://msdn.microsoft.com/en-us/library/windows/desktop/ms646270(v=vs.85).aspx
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    internal struct INPUT
    {
        public uint Type;
        public MOUSEKEYBDHARDWAREINPUT Data;
    }

    /// <summary>
    /// http://social.msdn.microsoft.com/Forums/en/csharplanguage/thread/f0e82d6e-4999-4d22-b3d3-32b25f61fb2a
    /// </summary>
    [StructLayout(LayoutKind.Explicit)]
    internal struct MOUSEKEYBDHARDWAREINPUT
    {
        [FieldOffset(0)]
        public HARDWAREINPUT Hardware;
        [FieldOffset(0)]
        public KEYBDINPUT Keyboard;
        [FieldOffset(0)]
        public MOUSEINPUT Mouse;
    }

    /// <summary>
    /// http://msdn.microsoft.com/en-us/library/windows/desktop/ms646310(v=vs.85).aspx
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    internal struct HARDWAREINPUT
    {
        public uint Msg;
        public ushort ParamL;
        public ushort ParamH;
    }

    /// <summary>
    /// http://msdn.microsoft.com/en-us/library/windows/desktop/ms646310(v=vs.85).aspx
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    internal struct KEYBDINPUT
    {
        public ushort Vk;
        public ushort Scan;
        public uint Flags;
        public uint Time;
        public IntPtr ExtraInfo;
    }

    /// <summary>
    /// http://social.msdn.microsoft.com/forums/en-US/netfxbcl/thread/2abc6be8-c593-4686-93d2-89785232dacd
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    internal struct MOUSEINPUT
    {
        public int X;
        public int Y;
        public uint MouseData;
        public uint Flags;
        public uint Time;
        public IntPtr ExtraInfo;
    }

然后最后改变你的点击事件：

private void btnGetBrowserProcess_Click(object sender, EventArgs e)
{
        Process[] procsChrome = Process.GetProcessesByName("chrome");
        foreach (Process chrome in procsChrome)
        {
            if (chrome.MainWindowHandle != IntPtr.Zero)
            {
                // Set focus on the window so that the key input can be received.
                SetForegroundWindow(chrome.MainWindowHandle);

                // Create a F5 key press
                INPUT ip = new INPUT { Type  =1};
                ip.Data.Keyboard = new KEYBDINPUT();
                ip.Data.Keyboard.Vk = (ushort)0x74;  // F5 Key
                ip.Data.Keyboard.Scan = 0;
                ip.Data.Keyboard.Flags = 0;
                ip.Data.Keyboard.Time = 0;
                ip.Data.Keyboard.ExtraInfo = IntPtr.Zero;

                var inputs = new INPUT[] { ip };

                // Send the keypress to the window
                SendInput(1, inputs, Marshal.SizeOf(typeof(INPUT)));

                // probably need to set focus back to your application here.
            }
        }
}

我自己试过了，我打开的当前 Chrome 标签页已成功刷新。我使用以下内容作为参考构建了这个示例：

• http://batchloaf.wordpress.com/2012/04/17/simulating-a-keystroke-in-win32-c-or-c-using-sendinput/
• Send keys through SendInput in user32.dll

很遗憾，我没有解释为什么 PostMessage 不适用于 Chrome，但我怀疑这与它的构建方式有关。