c# - 如何更改 win32 窗口上的文本？

Question

寻找从 C# 更改 win32 窗口上的文本的提示、技巧和搜索词。

更具体地说，我正在尝试将打印对话框上的文本从“打印”更改为“确定”，因为我正在使用该对话框来创建打印票而不进行任何打印。

如何找到对话框的窗口句柄？一旦我得到它，我将如何在表单的子窗口中找到按钮？一旦我发现，我将如何更改按钮上的文本？在显示对话框之前我怎么能做到这一切？

这里有一个类似的问题，但它指向了一篇 CodeProject 文章，它比需要的复杂得多，而且我解析的时间比我想花的时间要长一些。TIA。

Answer 1

You should use Spy++ to take a look at the dialog. The class name is important and the control ID of the button. If it is a native Windows dialog then the class name should be "#32770". In which case you'll have a lot of use for my post in this thread. Here is another in C#. You change the button text by P/Invoking SetWindowText() on the button handle.

---

using System;
using System.Text;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;

class SetDialogButton : IDisposable {
    private Timer mTimer = new Timer();
    private int mCtlId;
    private string mText;

    public SetDialogButton(int ctlId, string txt) {
        mCtlId = ctlId;
        mText = txt;
        mTimer.Interval = 50;
        mTimer.Enabled = true;
        mTimer.Tick += (o, e) => findDialog();
    }

    private void findDialog() {
        // Enumerate windows to find the message box
        EnumThreadWndProc callback = new EnumThreadWndProc(checkWindow);
        if (!EnumThreadWindows(GetCurrentThreadId(), callback, IntPtr.Zero)) mTimer.Enabled = false;
    }
    private bool checkWindow(IntPtr hWnd, IntPtr lp) {
        // Checks if <hWnd> is a dialog
        StringBuilder sb = new StringBuilder(260);
        GetClassName(hWnd, sb, sb.Capacity);
        if (sb.ToString() != "#32770") return true;
        // Got it, get the STATIC control that displays the text
        IntPtr hCtl = GetDlgItem(hWnd, mCtlId);
        SetWindowText(hCtl, mText);
        // Done
        return true;
    }
    public void Dispose() {
        mTimer.Enabled = false;
    }

    // P/Invoke declarations
    private const int WM_SETFONT = 0x30;
    private const int WM_GETFONT = 0x31;
    private delegate bool EnumThreadWndProc(IntPtr hWnd, IntPtr lp);
    [DllImport("user32.dll")]
    private static extern bool EnumThreadWindows(int tid, EnumThreadWndProc callback, IntPtr lp);
    [DllImport("kernel32.dll")]
    private static extern int GetCurrentThreadId();
    [DllImport("user32.dll")]
    private static extern int GetClassName(IntPtr hWnd, StringBuilder buffer, int buflen);
    [DllImport("user32.dll")]
    private static extern IntPtr GetDlgItem(IntPtr hWnd, int item);
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    private static extern bool SetWindowText(IntPtr hWnd, string txt);
}

Usage:

        using (new SetDialogButton(1, "Okay")) {
            printDialog1.ShowDialog();
        }