文本框不可点击但可编辑

问题描述

我有一个带有 10 个文本框的小表单，我将它们设置在正确的 Tab Order 中，目前我希望它们按 Tab To 的方式设置.我想知道是否有一种方法可以设置文本框，以便除非它们被标签进入，否则它们不能被选中进行编辑.即...我不希望最终用户能够单击文本框来编辑它们，我只希望它们可以通过 Tabbing 编辑.

I have a small form with 10 textboxes, I have them set in the right Tab Order currently the way I want them to Tab To. I was wondering if there is a way to set the textboxes up so they cannot be selected for editing unless they are Tabbed into. ie... I don't want the end user to be able to click on the textbox to edit them, I only want them editable through Tabbing.

推荐答案

这应该可以解决问题

public partial class PoorTextBox : TextBox
{
    protected override void WndProc(ref Message m)
    {
        if (m.Msg == (int) WM.LBUTTONDOWN)
        {
            return;//Eat mouse down events 
        }
        base.WndProc(ref m);
    }
}

可以在这里找到窗口消息枚举.<小时>如何在不继承 TextBox 的情况下做到这一点:

Window messages enum can be found here.

class EatMouseDown : NativeWindow
{
    protected override void WndProc(ref Message m)
    {
        if (m.Msg == (int)WM.LBUTTONDOWN)
        {
            return;
        }
        base.WndProc(ref m);
    }
}

protected override void OnLoad(EventArgs e)
{
    base.OnLoad(e);

    new EatMouseDown().AssignHandle(textBox1.Handle);//Subclass a Handle
}

<小时>如何在没有任何继承的情况下做到这一点:

省略了清理部分，这也很重要.这可能是错误的，但有效.推荐的方式是使用继承.从 .net fw src 中提取的所需方法.

Clean up part omitted, which is also important. This may be buggy but that works. Recommended way is to use inheritance. Required methods pulled from .net fw src.

class EatMouseDown
{
    public delegate IntPtr WndProc(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);

    #region External methods...

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern IntPtr SetWindowLong(HandleRef hWnd, int nIndex, WndProc wndproc);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern IntPtr SetWindowLongPtr(HandleRef hWnd, int nIndex, WndProc wndproc);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern IntPtr GetWindowLong(HandleRef hWnd, int nIndex);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern IntPtr GetWindowLongPtr(HandleRef hWnd, int nIndex);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern IntPtr DefWindowProc(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern IntPtr CallWindowProc(IntPtr wndProc, IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);

    #endregion

    private const int GWLP_WNDPROC = -4;
    private IntPtr handle;
    private IntPtr originalWndProc;
    private IntPtr currentWndProc;

    public static IntPtr SetWindowLongHelper(HandleRef hWnd, int nIndex, WndProc wndProc)
    {
        return IntPtr.Size == 4
            ? SetWindowLong(hWnd, nIndex, wndProc)
            : SetWindowLongPtr(hWnd, nIndex, wndProc);
    }

    public static IntPtr GetWindowLongHelper(HandleRef hWnd, int nIndex)
    {
        return IntPtr.Size == 4
            ? GetWindowLong(hWnd, nIndex)
            : GetWindowLongPtr(hWnd, nIndex);
    }

    internal void SubclassHandle(IntPtr handle)
    {
        this.handle = handle;
        this.originalWndProc = GetWindowLongHelper(new HandleRef(this, handle), GWLP_WNDPROC);
        SetWindowLongHelper(new HandleRef(this, handle), GWLP_WNDPROC, new WndProc(this.Callback));
        this.currentWndProc = GetWindowLongHelper(new HandleRef(this, handle), GWLP_WNDPROC);
    }

    private IntPtr Callback(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam)
    {
        var m = Message.Create(hwnd, msg, wparam, lparam);
        if (m.Msg == (int)WM.LBUTTONDOWN)
        {
            return IntPtr.Zero;
        }
        return CallWindowProc(originalWndProc, hwnd, msg, wparam, lparam);
    }
}

protected override void OnLoad(EventArgs e)
{
    base.OnLoad(e);

    new EatMouseDown().SubclassHandle(textBox1.Handle);//Subclass a Handle
}

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