C# 使用WinApi操作剪切板Clipboard
阿新 • • 發佈：2018-05-31
HERE 實現 range 圖片 there oid rto fin retrieve 
前言：
最近正好寫一個程序，需要操作剪切板
功能很簡單，只需要從剪切板內讀取字符串，然後清空剪切板，然後再把字符串導入剪切板
我想當然的使用我最拿手的C#來完成這項工作，原因無他，因為.Net框架封裝了能實現這種功能的方法
然後就有了如下代碼
1 string Temp = ""; 2 while (true) 3 { 4 string Tex = Clipboard.GetText().ToString(); 5 if (!string.IsNullOrWhiteSpace(Tex) && Temp != Tex)View Code6 { 7 Clipboard.Clear(); 8 Clipboard.SetDataObject(Tex, false); 9 Temp = Tex; 10 } 11 Thread.Sleep(1); 12 }
這段代碼，也是網頁上廣泛流傳的，使用.Net框架操作系統剪切板的方法，當然這個方法在某些情況下很管用
不過在我這確發生了點問題，主要的問題有兩點
首先，我對剪切板的操作需求有實時性，也就是，操作人員復制的一瞬間就應該截取到剪切板的數據，處理完後再放入剪切板
結果
Clipboard.SetDataObject(Tex, false);
沒想到上面這條設置剪切板的指令竟然會卡焦點窗口的線程，比如說，我在A軟件執行了一次復制操作，如果使用了上述代碼，那麽A軟件強制線程堵塞大概幾百毫秒的樣子，反正很影響體驗，我推測是因為該命令會鎖定內存導致的
那怎麽辦，本著死馬當活馬醫的態度，我專門為該指令啟用了一個線程
Task.Factory.StartNew(()=> { Clipboard.Clear(); Clipboard.SetDataObject(Text,false); });
使用了線程以後，因為操作滯後(線程啟動會延遲一會兒，並不實時)了，所以上述問題似乎解決了，但是沒想到出現了新的問題
string Tex = Clipboard.GetText().ToString();
上述從剪切板獲得字符串的指令，在默寫情況下，會卡滯住，然後程序在一分鐘之後，因為超時而被系統吊銷
emmmmm，在經過幾番努力之後，我終於意識到，雖然.Net封裝了不少操作系統API的方法，使得一些IO操作變簡單不少，但是帶來的問題也是同樣大的，在遇到無法解決的問題的時候，會有點束手無策
於是不得已，我只能放棄使用過C#完成該項功能，想著幸好功能簡單，而且操作WinAPI其實最好的還是使用C++來寫，於是我用C++復現了上述功能
1 #include "stdafx.h" 2 #include <windows.h> 3 #include <iostream> 4 using namespace std; 5 #pragma comment(linker,"/subsystem:windows /entry:mainCRTStartup") 6 7 int main(int argc, _TCHAR* argv[]) 8 { 9 HANDLE THandle = GlobalAlloc(GMEM_FIXED, 1000);//分配內存 10 char* Temp = (char*)THandle;//鎖定內存，返回申請內存的首地址 11 while (true) 12 { 13 HWND hWnd = NULL; 14 OpenClipboard(hWnd);//打開剪切板 15 if (IsClipboardFormatAvailable(CF_TEXT)) 16 { 17 HANDLE h = GetClipboardData(CF_TEXT);//獲取剪切板數據 18 char* p = (char*)GlobalLock(h); 19 GlobalUnlock(h); 20 if (strcmp(Temp, p)) 21 { 22 EmptyClipboard();//清空剪切板 23 HANDLE hHandle = GlobalAlloc(GMEM_FIXED, 1000);//分配內存 24 char* pData = (char*)GlobalLock(hHandle);//鎖定內存，返回申請內存的首地址 25 strcpy(pData, p); 26 strcpy(Temp, p); 27 SetClipboardData(CF_TEXT, hHandle);//設置剪切板數據 28 GlobalUnlock(hHandle);//解除鎖定 29 } 30 } 31 CloseClipboard();//關閉剪切板 32 Sleep(500); 33 } 34 return 0; 35 }View Code
不愧是C++，使用上述代碼後，完美實現我需要的功能，而且不管是主程序，還是我寫的這個程序，都不會出現卡滯或者不工作的情況了，真是可喜可賀。
那麽本教程就到此為止。
以下是正文
想著，既然我能用C++調用WinAPI完美實現我需要的功能，而且C#也能調用非托管的代碼來執行WinAPI，那麽我不是可以把上面C++寫的代碼移植到C#裏面執行？說幹就幹
首先，C#調用WinAPI需要先申明
[DllImport("User32")] internal static extern bool OpenClipboard(IntPtr hWndNewOwner); [DllImport("User32")] internal static extern bool CloseClipboard(); [DllImport("User32")] internal static extern bool EmptyClipboard(); [DllImport("User32")] internal static extern bool IsClipboardFormatAvailable(int format); [DllImport("User32")] internal static extern IntPtr GetClipboardData(int uFormat); [DllImport("User32", CharSet = CharSet.Unicode)] internal static extern IntPtr SetClipboardData(int uFormat, IntPtr hMem);
操作剪切板需要調用的API大致就上面這些
有了API以後，我們還需要自己手動封裝方法
internal static void SetText(string text) { OpenClipboard(IntPtr.Zero); EmptyClipboard(); SetClipboardData(13, Marshal.StringToHGlobalUni(text)); CloseClipboard(); } internal static string GetText(int format) { string value = string.Empty; OpenClipboard(IntPtr.Zero); if (IsClipboardFormatAvailable(format)) { IntPtr ptr = NativeMethods.GetClipboardData(format); if (ptr != IntPtr.Zero) { value = Marshal.PtrToStringUni(ptr); } } CloseClipboard(); return value; }
我們也就用到兩個方法，從剪切板獲得文本和設置文本到剪切板，哦關於SetClipboardData的第一個參數13是怎麽來的問題，其實這個剪切板的格式參數，下面有一張表，就是自從這裏來的
public static class ClipboardFormat { /// <summary> /// Text format. Each line ends with a carriage return/linefeed (CR-LF) combination. A null character signals /// the end of the data. Use this format for ANSI text. /// </summary> public const int CF_TEXT = 1; /// <summary> /// A handle to a bitmap (<c>HBITMAP</c>). /// </summary> public const int CF_BITMAP = 2; /// <summary> /// Handle to a metafile picture format as defined by the <c>METAFILEPICT</c> structure. When passing a /// <c>CF_METAFILEPICT</c> handle by means of DDE, the application responsible for deleting <c>hMem</c> should /// also free the metafile referred to by the <c>CF_METAFILEPICT</c> handle. /// </summary> public const int CF_METAFILEPICT = 3; /// <summary> /// Microsoft Symbolic Link (SYLK) format. /// </summary> public const int CF_SYLK = 4; /// <summary> /// Software Arts‘ Data Interchange Format. /// </summary> public const int CF_DIF = 5; /// <summary> /// Tagged-image file format. /// </summary> public const int CF_TIFF = 6; /// <summary> /// Text format containing characters in the OEM character set. Each line ends with a carriage return/linefeed /// (CR-LF) combination. A null character signals the end of the data. /// </summary> public const int CF_OEMTEXT = 7; /// <summary> /// A memory object containing a <c>BITMAPINFO</c> structure followed by the bitmap bits. /// </summary> public const int CF_DIB = 8; /// <summary> /// Handle to a color palette. Whenever an application places data in the clipboard that depends on or assumes /// a color palette, it should place the palette on the clipboard as well. If the clipboard contains data in /// the <see cref="CF_PALETTE"/> (logical color palette) format, the application should use the /// <c>SelectPalette</c> and <c>RealizePalette</c> functions to realize (compare) any other data in the /// clipboard against that logical palette. When displaying clipboard data, the clipboard always uses as its /// current palette any object on the clipboard that is in the <c>CF_PALETTE</c> format. /// </summary> public const int CF_PALETTE = 9; /// <summary> /// Data for the pen extensions to the Microsoft Windows for Pen Computing. /// </summary> public const int CF_PENDATA = 10; /// <summary> /// Represents audio data more complex than can be represented in a CF_WAVE standard wave format. /// </summary> public const int CF_RIFF = 11; /// <summary> /// Represents audio data in one of the standard wave formats, such as 11 kHz or 22 kHz PCM. /// </summary> public const int CF_WAVE = 12; /// <summary> /// Unicode text format. Each line ends with a carriage return/linefeed (CR-LF) combination. A null character /// signals the end of the data. /// </summary> public const int CF_UNICODETEXT = 13; /// <summary> /// A handle to an enhanced metafile (<c>HENHMETAFILE</c>). /// </summary> public const int CF_ENHMETAFILE = 14; /// <summary> /// A handle to type <c>HDROP</c> that identifies a list of files. An application can retrieve information /// about the files by passing the handle to the <c>DragQueryFile</c> function. /// </summary> public const int CF_HDROP = 15; /// <summary> /// The data is a handle to the locale identifier associated with text in the clipboard. When you close the /// clipboard, if it contains <c>CF_TEXT</c> data but no <c>CF_LOCALE</c> data, the system automatically sets /// the <c>CF_LOCALE</c> format to the current input language. You can use the <c>CF_LOCALE</c> format to /// associate a different locale with the clipboard text. /// An application that pastes text from the clipboard can retrieve this format to determine which character /// set was used to generate the text. /// Note that the clipboard does not support plain text in multiple character sets. To achieve this, use a /// formatted text data type such as RTF instead. /// The system uses the code page associated with <c>CF_LOCALE</c> to implicitly convert from /// <see cref="CF_TEXT"/> to <see cref="CF_UNICODETEXT"/>. Therefore, the correct code page table is used for /// the conversion. /// </summary> public const int CF_LOCALE = 16; /// <summary> /// A memory object containing a <c>BITMAPV5HEADER</c> structure followed by the bitmap color space /// information and the bitmap bits. /// </summary> public const int CF_DIBV5 = 17; /// <summary> /// Owner-display format. The clipboard owner must display and update the clipboard viewer window, and receive /// the <see cref="ClipboardMessages.WM_ASKCBFORMATNAME"/>, <see cref="ClipboardMessages.WM_HSCROLLCLIPBOARD"/>, /// <see cref="ClipboardMessages.WM_PAINTCLIPBOARD"/>, <see cref="ClipboardMessages.WM_SIZECLIPBOARD"/>, and /// <see cref="ClipboardMessages.WM_VSCROLLCLIPBOARD"/> messages. The <c>hMem</c> parameter must be <c>null</c>. /// </summary> public const int CF_OWNERDISPLAY = 0x0080; /// <summary> /// Text display format associated with a private format. The <c>hMem</c> parameter must be a handle to data /// that can be displayed in text format in lieu of the privately formatted data. /// </summary> public const int CF_DSPTEXT = 0x0081; /// <summary> /// Bitmap display format associated with a private format. The <c>hMem</c> parameter must be a handle to /// data that can be displayed in bitmap format in lieu of the privately formatted data. /// </summary> public const int CF_DSPBITMAP = 0x0082; /// <summary> /// Metafile-picture display format associated with a private format. The <c>hMem</c> parameter must be a /// handle to data that can be displayed in metafile-picture format in lieu of the privately formatted data. /// </summary> public const int CF_DSPMETAFILEPICT = 0x0083; /// <summary> /// Enhanced metafile display format associated with a private format. The <c>hMem</c> parameter must be a /// handle to data that can be displayed in enhanced metafile format in lieu of the privately formatted data. /// </summary> public const int CF_DSPENHMETAFILE = 0x008E; /// <summary> /// Start of a range of integer values for application-defined GDI object clipboard formats. The end of the /// range is <see cref="CF_GDIOBJLAST"/>. Handles associated with clipboard formats in this range are not /// automatically deleted using the <c>GlobalFree</c> function when the clipboard is emptied. Also, when using /// values in this range, the <c>hMem</c> parameter is not a handle to a GDI object, but is a handle allocated /// by the <c>GlobalAlloc</c> function with the <c>GMEM_MOVEABLE</c> flag. /// </summary> public const int CF_GDIOBJFIRST = 0x0300; /// <summary> /// See <see cref="CF_GDIOBJFIRST"/>. /// </summary> public const int CF_GDIOBJLAST = 0x03FF; /// <summary> /// Start of a range of integer values for private clipboard formats. The range ends with /// <see cref="CF_PRIVATELAST"/>. Handles associated with private clipboard formats are not freed /// automatically; the clipboard owner must free such handles, typically in response to the /// <see cref="ClipboardMessages.WM_DESTROYCLIPBOARD"/> message. /// </summary> public const int CF_PRIVATEFIRST = 0x0200; /// <summary> /// See <see cref="CF_PRIVATEFIRST"/>. /// </summary> public const int CF_PRIVATELAST = 0x02FF; }View Code
在C++裏面是不用指定數字的，只需要用CF_UNICODETEXT就行，不過.Net裏面應該沒有對應的索引表，所以只能手動輸入(我這裏是為了說明用才專門用數字，自己代碼那是索引的枚舉類)
上面兩個工作做完以後，就能實現功能了，功能代碼如下
var LastS = string.Empty; while (!CancelInfoClipboard.IsCancellationRequested) { var Temp = ClipboardControl.GetText(ClipboardFormat.CF_UNICODETEXT); if (!string.IsNullOrEmpty(Temp) && Temp != LastS) { ClipboardControl.SetText(Temp); LastS = Temp; } Thread.Sleep(50); }
是不是和最開始展示的調用.Net框架的方法一模一樣(笑)，不過使用底層API實現的功能，就沒有那麽多亂七八糟的Bug了，自己也很清楚到底實現了啥功能，同時也收獲了不少新知識(主要是非托管代碼調用的時候的註意事項什麽的，還有，向非托管代碼傳遞數據的時候，最好多用Marshal類裏面的方法，不然可能會出錯，畢竟這個類就是專門為非托管代碼而設立的)
以上
C# 使用WinApi操作剪切板Clipboard