窃取键盘输入preventing对焦，能够控制 [英] Preventing Focus-able Controls from stealing Keyboard Input

问题描述

我目前工作的一个简单的游戏，是通过覆盖的OnPaint 方法绘制的表格上。游戏需要键盘输入和进行工作完美，直到我决定以增强图形用户界面，并添加几个按钮的形式。

I'm currently working on a simple game that is drawn on a form by overriding the OnPaint method. The game requires Keyboard input and was working perfectly until I decided to enhance the GUI and add a few Buttons to the form.

我添加了这些按钮的那一刻，形式停止接受任何键盘输入，无论我如何努力的重点是始终上的按钮。这种行为可以通过放置在窗体上的任何关注，能够控制被复制。 （即文本框）

The moment I added these Buttons, the form stopped receiving any Keyboard input, no matter how hard I tried the focus was always on the buttons. This behavior can be replicated by placing any Focus-able Control on the form. (ie. TextBox)

我不需要使用这些按钮任何Kayboard互动，我希望用户与他们进行互动，只有鼠标。

我尝试以下方法来尝试解决这个问题 - 所有这些工作：

I've tried the following techniques to try and get around this problem - none of these worked:

• 1）正常的KeyDown 的形式和的KeyUp 事件。 （这是这样 我把按钮之前捕获键盘输入。）
• 2）覆盖窗体的的onkeydown 和的onkeyup 事件。
• 3）重写 ProcessCmdKey - 作品，但不能区分 的KeyUp和的KeyDown事件之间，所以它是不够的我。

• 1) Normal KeyDown and KeyUp events of the form. (This is the way I was capturing Keyboard input before placing the buttons.)
• 2) Overriding the Form's OnKeyDown and OnKeyUp events.
• 3) Overriding ProcessCmdKey - Works, but cannot differentiate between KeyUp and KeyDown events, so it is inadequate for me.

我也尝试创建一个MessageFilter的应用程序，但我不能强迫它仅捕获，我需要的键盘按键。

I also tried create a MessageFilter for the application, but I couldn't force it to capture only the Keyboard keys that I needed.

我一直在寻找到这几个小时已经并不能找到一个合适的解决方案。 帮助将不胜AP preciated。

I've been looking into this for many hours already and can't find a suitable solution. Help would be greatly appreciated.

推荐答案

下面是一个示例形式的 IMessageFilter 的向上和向下箭头键，希望这有助于：

Here is a sample form with a IMessageFilter for the up and down arrow keys, hope this helps:

public partial class MainForm : Form
{
    private class MessageFilter : IMessageFilter
    {
        public MainForm Main { get; set; }
        public bool PreFilterMessage(ref Message msg)
        {
            const int WM_KEYDOWN = 0x100;
            const int WM_KEYUP = 0x101;
            if (msg.Msg == WM_KEYDOWN)
            {
                var keyData = (Keys)msg.WParam;
                if (keyData == Keys.Down || keyData == Keys.Up)
                {
                    return true; // Process keys before return
                }
            }
            else if (msg.Msg == WM_KEYUP)
            {
                var keyData = (Keys)msg.WParam;
                if (keyData == Keys.Down || keyData == Keys.Up)
                {
                    return true; // Process keys before return
                }
            }
            return false;
        }
    }
    public MainForm()
    {
        this.InitializeComponent();
        Application.AddMessageFilter(new MessageFilter { Main = this });
    }
}

有关可能的Windows消息的列表查询：

For a list of possible Windows messages check:

列表Windows消息

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