故事背景：java組的小伙伴需要一個能在ie（還是6。。。）下截圖并返回給網頁的功能，但是ie做起來很麻煩（可能根本做不到），于是找到我寫一個activex控件實現此功能，想著可能還有其他小伙伴需要這個功能，于是就po出來，供需要的人使用，當然也可以作為學習c#編寫activex的一個簡單入門教程（vc++效果更好）。
功能截圖如下：
代碼分為兩個核心部分：1、c#屏幕截圖；2、c#開發activx控件。
1、屏幕截圖，這個在網上找到了一個只需要5行代碼的實現（超級精簡），當然你也可以費點功夫實現自由區域截取圖片，截圖后保存到本地，然后使用二進制讀取jpg文件，并編碼為base64返回給網頁
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public string printscreen() { image baseimage = new bitmap(screen.primaryscreen.bounds.width, screen.primaryscreen.bounds.height); graphics g = graphics.fromimage(baseimage); g.copyfromscreen(new point(0, 0), new point(0, 0), screen.allscreens[0].bounds.size); g.dispose(); baseimage.save("d:\\screen.jpg", imageformat.jpeg); stream file = new filestream("d:\\screen.jpg", filemode.open); binaryreader bw = new binaryreader(file); var buffer = new byte[file.length]; bw.read(buffer, 0, buffer.length); bw.close(); string b64 = convert.tobase64string(buffer); return b64; } |
2、c#開發activex控件，網上示例比較多
先新建一個類庫，并設置項目屬性，com可見
并為com互注冊，這樣編譯完了會自動注冊com控件
完成設置后，編寫代碼，如下：
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using system;using system.collections.generic;using system.text;using system.runtime.interopservices;namespace printscreenlib{ //為了讓activex控件獲得客戶端的信任，控件類需要實現一個名為“iobjectsafety”的接口。先創建該接口（注意，不能修改該接口的guid值） [comimport, guid("cb5bdc81-93c1-11cf-8f20-00805f2cd064")] [interfacetype(cominterfacetype.interfaceisiunknown)] public interface iobjectsafety { [preservesig] int getinterfacesafetyoptions(ref guid riid, [marshalas(unmanagedtype.u4)] ref int pdwsupportedoptions, [marshalas(unmanagedtype.u4)] ref int pdwenabledoptions); [preservesig()] int setinterfacesafetyoptions(ref guid riid, [marshalas(unmanagedtype.u4)] int dwoptionsetmask, [marshalas(unmanagedtype.u4)] int dwenabledoptions); }} |
新建用戶控件，并派生iobjectsafe接口，接口實現是固定內容
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[guid("61d7f413-a1b2-48a9-b851-5bfbcf50280c")] //使用vs工具里的guid生成器生成唯一碼public partial class pslib : usercontrol, iobjectsafety{#region iobjectsafety 成員private const string _iid_idispatch = "{00020400-0000-0000-c000-000000000046}";private const string _iid_idispatchex = "{a6ef9860-c720-11d0-9337-00a0c90dcaa9}";private const string _iid_ipersiststorage = "{0000010a-0000-0000-c000-000000000046}";private const string _iid_ipersiststream = "{00000109-0000-0000-c000-000000000046}";private const string _iid_ipersistpropertybag = "{37d84f60-42cb-11ce-8135-00aa004bb851}";private const int interfacesafe_for_untrusted_caller = 0x00000001;private const int interfacesafe_for_untrusted_data = 0x00000002;private const int s_ok = 0;private const int e_fail = unchecked((int)0x80004005);private const int e_nointerface = unchecked((int)0x80004002);private bool _fsafeforscripting = true;private bool _fsafeforinitializing = true;public int getinterfacesafetyoptions(ref guid riid, ref int pdwsupportedoptions, ref int pdwenabledoptions){ int rslt = e_fail; string strguid = riid.tostring("b"); pdwsupportedoptions = interfacesafe_for_untrusted_caller | interfacesafe_for_untrusted_data; switch (strguid) { case _iid_idispatch: case _iid_idispatchex: rslt = s_ok; pdwenabledoptions = 0; if (_fsafeforscripting == true) pdwenabledoptions = interfacesafe_for_untrusted_caller; break; case _iid_ipersiststorage: case _iid_ipersiststream: case _iid_ipersistpropertybag: rslt = s_ok; pdwenabledoptions = 0; if (_fsafeforinitializing == true) pdwenabledoptions = interfacesafe_for_untrusted_data; break; default: rslt = e_nointerface; break; } return rslt;}public int setinterfacesafetyoptions(ref guid riid, int dwoptionsetmask, int dwenabledoptions){ int rslt = e_fail; string strguid = riid.tostring("b"); switch (strguid) { case _iid_idispatch: case _iid_idispatchex: if (((dwenabledoptions & dwoptionsetmask) == interfacesafe_for_untrusted_caller) && (_fsafeforscripting == true)) rslt = s_ok; break; case _iid_ipersiststorage: case _iid_ipersiststream: case _iid_ipersistpropertybag: if (((dwenabledoptions & dwoptionsetmask) == interfacesafe_for_untrusted_data) && (_fsafeforinitializing == true)) rslt = s_ok; break; default: rslt = e_nointerface; break; } return rslt;}#endregion |
ie調用activex控件：
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<!doctype html><html> <head> <title>測試</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <script> function jt(){ var str=""; try { var obj = document.getelementbyid("myactivex"); str=obj.printscreen(); } catch(e) { alert(e); return; } var img=document.getelementbyid("img"); img.src="data:image/jpeg;base64,"+str;//接受base64編碼后的圖片 } </script> </head> <body> <object id="myactivex" width="120" height=20" classid="clsid:61d7f413-a1b2-48a9-b851-5bfbcf50280c"></object> <input type="button" value="截圖" onclick="jt();"> <image id ="img" /> </body></html> |
一個完整的actviex控件就完成了，這里沒有使用到事件，如果使用事件的話會更加麻煩一點。
下載：屏幕截圖activx控件
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持服務器之家。
