建议的解决方案如前所述：
另存为文件对话框（在此示例中使用）与一个名为 CustomSaveFileDialog 的用户控件相关联。它的优点是它存在于工具箱中，并且它自动实现了 IDisposable 接口。但是，它也可以是一个简单的 C# 类。
这个控件有一个构造函数，它接受一个任意应用程序特定的用户控件，它承载了所有要显示在文件对话框中的元素。当我答对问题时，这就是必需的。
CustomSaveFileDialog 具有以下属性：
- 接受停靠在文件底部的任意用户控件
对话框，即它们遵循文件对话框的大小调整
- 其他元素（按钮、图像、
复选框等）是必要的。他们的行为很正常，就像在其他
窗户。
这是所描述类的代码：
using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Diagnostics;
namespace customSaveFileDialog
{
public partial class CustomSaveFileDialog : UserControl
{
//https://stackoverflow.com/questions/9665579/setting-up-hook-on-windows-messages
delegate void WinEventDelegate(IntPtr hWinEventHook, uint eventType,
IntPtr hwnd, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime);
const uint WINEVENT_OUTOFCONTEXT = 0;
[DllImport("user32.dll")]
private static extern IntPtr SetWinEventHook(uint eventMin, uint eventMax, IntPtr
hmodWinEventProc, WinEventDelegate lpfnWinEventProc, uint idProcess,
uint idThread, uint dwFlags);
[DllImport("user32.dll")]
private static extern bool UnhookWinEvent(IntPtr hWinEventHook);
[DllImport("user32.dll")]
private static extern bool MoveWindow(IntPtr hWnd, int x, int y, int w, int h, bool repaint);
private struct RECT { public int Left; public int Top; public int Right; public int Bottom; }
[DllImport("user32.dll")]
private static extern bool GetClientRect(IntPtr hWnd, out RECT rc);
[DllImport("kernel32.dll")]
private static extern uint GetLastError();
[DllImport("user32.dll", SetLastError = true)]
private static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
[DllImport("user32.dll", SetLastError = true)]
private static extern IntPtr SetParent(IntPtr hwndChild, IntPtr hwndNewParent);
[DllImport("user32.dll", SetLastError = true)]
private static extern IntPtr GetParent(IntPtr hWnd);
private IntPtr hDlg; // Save As dialog handle
private IntPtr hHook; // Event hook
private IntPtr hCtrl; // App. specific user control handle
UserControl ctrl; // App. specific user control
//Static variable containing the instance object
private static CustomSaveFileDialog customSaveFileDialog;
//public property for the user
//theSaveFileDialog has been added to the control in the designer from the Toolbox
public SaveFileDialog Dlg { get { return theSaveFileDialog; } }
//Event hook delegate
private static WinEventDelegate procDelegate = new WinEventDelegate(WinEventProc);
/// <summary>
/// Constructor
/// </summary>
/// <param name="ctrl">The User Control to be displayed in the file dialog</param>
public CustomSaveFileDialog(UserControl ctrl)
{
InitializeComponent();
customSaveFileDialog = this;
this.ctrl = ctrl;
hCtrl = ctrl.Handle;
//Setup Hook; for simplicity, hook all possible events from the current process
hHook = SetWinEventHook(1, 0x7fffffff, IntPtr.Zero,
procDelegate, (uint)Process.GetCurrentProcess().Id, 0, WINEVENT_OUTOFCONTEXT);
}
// Hook function
static void WinEventProc(IntPtr hWinEventHook, uint eventType,
IntPtr hwnd, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime)
{
CustomSaveFileDialog csfdg = customSaveFileDialog;
if (csfdg.hDlg == IntPtr.Zero)
csfdg.hDlg = FindWindowEx(IntPtr.Zero, IntPtr.Zero, "#32770", "Save As");
if (hwnd == csfdg.hDlg)
{
IntPtr hParent = GetParent(csfdg.hCtrl);
//this is done only once
if (!(hParent == csfdg.hDlg))
SetParent(csfdg.hCtrl, csfdg.hDlg); //Bind the user control to the Common Dialog
RECT cliRect;
GetClientRect(csfdg.hDlg, out cliRect);
//Position the button in the file dialog
MoveWindow(csfdg.hCtrl, cliRect.Left + 130, cliRect.Bottom - 55, 500, 60, true);
}
}
}
}
最重要的部分是windows事件的挂钩。这取自that post。
可能需要注意的是，“FindWindowEx”函数（在 WinEventProc 中）会查找所有标题为“另存为”的通用对话框（可能还有更多）。如果这应该是一个问题，则需要进行更多过滤，例如仅在当前线程中搜索。可以在here找到这样的搜索功能。
此外（上述代码中未显示）CustormSaveFileDialog.desinger.cs 中的“Dispose”方法包含以 hHook 句柄为参数的 Unhook 函数。
该软件已在 Windows7 的调试模式下进行了测试。作为测试，实现了一个带有按钮的简单表单窗口：
//Test for the customized "Save As" dialog
private void button1_Click(object sender, EventArgs e)
{
//Arbitrary User Control
myUserControl ctrl = new myUserControl();
using (CustomSaveFileDialog csfdg = new CustomSaveFileDialog(ctrl))
{
csfdg.Dlg.FileName = "test";
//Show the Save As dialog associated to the CustomFileDialog control
DialogResult res = csfdg.Dlg.ShowDialog();
if (res == System.Windows.Forms.DialogResult.OK)
MessageBox.Show("Save Dialog Finished");
}
}
并且 - 以及测试 - 特定于应用程序的用户控件处理以下事件：
using System;
using System.Windows.Forms;
namespace CustomFile
{
public partial class myUserControl : UserControl
{
public myUserControl()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
MessageBox.Show("Button Clicked");
}
private void pictureBox1_Click(object sender, EventArgs e)
{
MessageBox.Show("Image Clicked");
}
private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
if (!checkBox1.Checked)
pictureBox1.Visible = false;
else
pictureBox1.Visible = true;
}
}
}
产生以下输出：
下一张图是另一个截图，文件对话框调整了大小，显示图片的复选框没有选中。