Adobe AxAcroPDF控件无法返回当前页码。我只是在制作一个个人实用工具,所以我很幸运地采用了一种我认为可以分享的黑客方法......它与网上的点点滴滴一起打补丁。它使用User32.dll中的Windows本机函数枚举控件的子项,并在工具栏中找到与页码对应的文本框。然后使用SendMessage调用读取该文本。
答案 0 :(得分:1)
此方法枚举adobe pdf查看器的子组件,并在工具栏中查找文本框。其中一个文本框是页码,一个是当前缩放值。没有'%'的文本框在其内容中被视为页码文本框。使用SendMessage函数检索文本框的内容。
您可能需要先在查看器组件上调用SetToolbarVisible(true),以确保工具栏(以及文本框)可见。
这是一个糟糕的hacky解决方案,随着Adobe更新观众,可能很容易破解。如果Adobe会添加一个" getCurrentPage"那就太好了。所以这一切都可以避免。
//you can get the handle parameter for this method as: yourPDFControl.Handle
public static string GetPageNumber(IntPtr adobeViewerHandle)
{
//get a list of all windows held by parent
List<IntPtr> childrenWindows = new List<IntPtr>();
GCHandle listHandle = GCHandle.Alloc(childrenWindows);
try
{
EnumWindowProc childProc = new EnumWindowProc(EnumWindow);
EnumChildWindows(adobeViewerHandle, childProc, GCHandle.ToIntPtr(listHandle));
}
finally
{
if (listHandle.IsAllocated)
listHandle.Free();
}
//now have a list of the children, look for text boxes with class name "Edit"
for (int i = 0; i < childrenWindows.Count; i++)
{
int nRet;
// Pre-allocate 256 characters, the maximum class name length.
StringBuilder ClassName = new StringBuilder(256);
//Get the window class name
nRet = GetClassName(childrenWindows.ElementAt(i), ClassName, ClassName.Capacity);
if (ClassName.ToString().CompareTo("Edit") == 0)
{
IntPtr resultPointer = Marshal.AllocHGlobal(200);
StringBuilder text = new StringBuilder(20);
NativeMethods.SendMessage(childrenWindows.ElementAt(i), 0x000D, text.Capacity, text); //0x000D is WM_GETTEXT message
if (text.ToString().Contains("%")) //we don't want the text box for the PDF scale (e.g. 66.7% zoomed etc.)
{
continue;
} else
{
return text.ToString(); // the only other text box is the page number box
}
}
}
//Note I return as a string because PDF supports page labels, "I", "ii", "iv" etc. or even section labels "A", "B". So you're not guaranteed a numerical page number.
return "0";
}
private static bool EnumWindow(IntPtr handle, IntPtr pointer)
{
GCHandle gch = GCHandle.FromIntPtr(pointer);
List<IntPtr> list = gch.Target as List<IntPtr>;
if (list == null)
throw new InvalidCastException("GCHandle Target could not be cast as List<IntPtr>");
list.Add(handle);
return true;
}
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool EnumChildWindows(IntPtr window,
EnumWindowProc callback,
IntPtr i);
internal delegate bool EnumWindowProc(IntPtr hWnd, IntPtr parameter);
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
internal static extern int GetWindowTextLength(IntPtr hWnd);
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
internal static extern int GetWindowText(IntPtr hWnd,
StringBuilder lpString,
int nMaxCount);
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
internal static extern int GetClassName(IntPtr hWnd, StringBuilder lpClassName, int nMaxCount);
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
internal static extern bool SendMessage(IntPtr hWnd, uint Msg, int wParam, StringBuilder lParam);