牛牛截图，web端的一款截图工具，下面是代码及实例。

依赖jquery-1.7.min.js

/*******************************************************************************
牛牛截图的JS部分的核心流程封装在此文件中，绝大部分情况下，您不需要修改此文件中的JS内容，它已经包含了在所有浏览器上应用
牛牛截图所需要的所有代码，您只需要去修改capturewrapper.js，将相应的函数修改成与您的UI匹配的即可
*******************************************************************************//*******************************************************************************/
//设置截图的参数
var emPensize = 1;      //设置画笔大小
var emDrawType = 2;     //设置是腾讯风格还是360风格 0： 腾讯风格   1： 360风格
var emTrackColor = 3;       //自动识别的边框的颜色
var emEditBorderColor = 4;  //文本输入的边框颜色
var emTransparent = 5;      //工具栏的透明度
var emWindowAware = 6;      //设置是否禁用随着DPI放大
var emSetSaveName = 8;      //设置保存时的开始文字     免费版本无效
var emSetMagnifierBkColor = 9; //设置放大镜的背景色，不设置则透明
var emSetMagnifierLogoText = 10; //设置放大镜上的LOGO字符，可提示快捷键，如： 牛牛截图(CTRL + SHIFT + A)     免费版本无效
var emSetWatermarkPictureType = 20;                     //设置水印的类型
var emSetWatermarkPicturePath = 21;                     //设置水印的路径
var emSetWatermarkTextType = 22;                        //设置水印文字的类型
var emSetWatermarkTextValue = 23;                       //设置水印文字的字符串
var emSetMosaicType = 24;               //指定马赛克的类型，1为矩形，2为画线
var emSetTooltipText = 25;               //用于设置工具栏图标的TOOLTIP文字
var emSetMoreInfo = 26;                         //设置额外的信息，用于特殊需求
/*******************************************************************************/var emClosed = 1;
var emConnected = 2;
var emConnecting = 3;var emCaptureSuccess = 0;
var emCaptureFailed = 1;
var emCaptureUnknown = 2;var emCmdReady = -1;
var emCmdCapture = 0;
var emCmdSaveFile = 1;function isMacintosh() {return navigator.platform.indexOf('Mac') > -1;
}function rgb2value(r, g, b)
{return r | g << 8 | b << 16;
}var captureObjSelf = null;
function onpluginLoaded()
{captureObjSelf.pluginLoaded();
}function NiuniuCaptureObject()
{var self = this;captureObjSelf = this;this.PenSize = 2;this.DrawType = 0;this.TrackColor = rgb2value(255, 0, 0);this.EditBorderColor = rgb2value(255, 0, 0);this.Transparent = 240;this.WindowAware = 1;this.MosaicType = 1;this.SaveName = "保存";this.MagnifierLogoText = "截图";this.WatermarkPictureType = "2|100|100|400|400|20";this.WatermarkPicturePath = "";this.WatermarkTextType = "2|100|100|100|40|20|0|150|30|80,55,55,55";this.WatermarkTextValue = "";this.NiuniuAuthKey = "";this.ToolTipText = "";  //tipRectangle|tipCircle|tipArrow|tipBrush|tipGlitter|tipMosaic|tipText|tipUndo|tipSave|tipCancel|tipFinish|txtFinishthis.MoreInfo = "1,100|300|600";this.useCustomizedProtoco = true;   //是否使用浏览器自定义协议加websocket this.IsWaitCustomizedCallBack = false;this.autoConnectAfterPageLoad = true;this.IsFirstConnect = true;this.IsEverConnected = false;this.reconnectTryTime = 0;this.TimeIntervalID = -1;this.ReceivedEchoBack = false;this.Version = "1.0.0.0";this.hostPort = "30101,30102";this.hostPortIndex = 0;this.CaptureName = "NiuniuCapture";  this.NiuniuSocket = null;this.connectState = emClosed;this.SocketTimeStamp = new Date().getTime();this.TimeOutID = -1;this.FinishedCallback = null;this.PluginLoadedCallback = null;this.VersionCallback = null;this.OnConnectFailed = function(isReconnect){self.WriteLog(isReconnect ? "reconnect failed, the capture control process is exit." : "connect failed at the first time.");}this.LoadPlugin = function(){var obj = $('#capturecontainer');if(obj.length < 1){$("body").append('<div id="capturecontainer" style="height:0px;width:0px;"></div>');obj = $('#capturecontainer');}        obj.html('');obj.html('<object id="niuniuCapture" type="application/x-niuniuwebcapture" width="0" height="0"><param name="onload" value="onpluginLoaded" /></object>');var iframeObj = $('startCaptureFrame');if(iframeObj.length < 1){$("body").append('<iframe id="startCaptureFrame" style="display:none;"></iframe>');         }}this.niuniuCapture = function (){return document.getElementById('niuniuCapture');}this.addEvent = function(obj, name, func){if (obj.attachEvent) {obj.attachEvent("on"+name, func);} else {obj.addEventListener(name, func, false); }}this.pluginValid = function(){try{if(self.niuniuCapture().valid){return true;}}catch(e){}return false;        }this.OnCaptureFinished = function(x, y, width, height, content,localpath) {self.OnCaptureFinishedEx(1, x, y, width, height, "", content,localpath);      }this.OnCaptureFinishedEx = function(type, x, y, width, height, info, content,localpath) {//交给上层去处理截图完成后的事项 if(self.FinishedCallback != null){self.FinishedCallback(type, x, y, width, height, info, content,localpath);}else{alert("截图完成的事件未绑定，将不能对图片进行处理，请指定FinishedCallback回调函数");}}this.pluginLoaded = function(){self.GetVersion();if(!self.pluginValid()){if(self.PluginLoadedCallback != null){self.PluginLoadedCallback(false);}return false;}   //此函数必需调用，传递正确的参数，且必需先于其他函数调用  self.niuniuCapture().InitCapture(self.NiuniuAuthKey); self.niuniuCapture().InitParam(emPensize, self.PenSize);self.niuniuCapture().InitParam(emDrawType, self.DrawType);self.niuniuCapture().InitParam(emTrackColor, self.TrackColor);self.niuniuCapture().InitParam(emEditBorderColor, self.EditBorderColor);self.niuniuCapture().InitParam(emTransparent, self.Transparent);self.niuniuCapture().InitParam(emSetSaveName, self.SaveName);            self.niuniuCapture().InitParam(emSetMagnifierLogoText, self.MagnifierLogoText);self.niuniuCapture().InitParam(emSetMosaicType, self.MosaicType);//设置工具栏上的按钮TOOLTIP  self.niuniuCapture().InitParam(emSetTooltipText, self.ToolTipText);self.niuniuCapture().InitParam(emSetMoreInfo, self.MoreInfo);//niuniuCapture().InitParam(23, "测试文字.");//此BASE64字符串表示牛牛默认的水印图片，可以替换// niuniuCapture().InitParam(21, "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");//注：以上设置LOGO及保存名的接口，免费版本无效//添加控件的事件监听 self.addEvent(self.niuniuCapture(), 'CaptureFinishedEx', self.OnCaptureFinishedEx);//以下这个事件主要是用于兼容旧的浏览器控件的事件通知self.addEvent(self.niuniuCapture(), 'CaptureFinished', self.OnCaptureFinished);if(self.PluginLoadedCallback != null){self.PluginLoadedCallback(true);}}this.SetWatermarkPicture = function(watermarPicData){self.WatermarkPicturePath = watermarPicData;//设置测试的水印图片的Base64字符串，此操作应该是在页面加载中处理比较合适 if(!self.pluginValid())return;self.niuniuCapture().InitParam(emSetWatermarkPicturePath, self.WatermarkPicturePath);        self.niuniuCapture().InitParam(emSetWatermarkPictureType, self.WatermarkPictureType);}this.SetWatermarkText = function(watermarkText){self.WatermarkTextValue = watermarkText;//设置测试的水印文字，此操作应该是在页面加载中处理比较合适 if(!self.pluginValid())return;//nShowType|nMinWidth|nMinHeight|nVerticalInterval|nOffset|nFontSize|nIsBold|nTextWidth|nTextHeight|colorTextself.niuniuCapture().InitParam(emSetWatermarkTextValue, self.WatermarkTextValue);self.niuniuCapture().InitParam(emSetWatermarkTextType, self.WatermarkTextType);}this.SavePicture = function(savename){if(self.pluginValid()){self.niuniuCapture().SavePicture(savename);}}this.GetCursorPosition = function(){if(self.pluginValid()){var val = self.niuniuCapture().GetCursorPosition();return val;}return "";}this.NewCaptureParamObject = function(defaultpath, hideCurrWindow, autoCaptureFlag, x, y, width, height){  var obj = new Object(); obj.CmdType = 1;obj.IsGBK = 0;               //是否是GBK编码，这样会涉及到编码转换  obj.AuthKey = self.NiuniuAuthKey;  //                     obj.Pensize = self.PenSize;     //设置画笔大小obj.DrawType = self.DrawType;           //设置是腾讯风格还是360风格obj.TrackColor= self.TrackColor;        //自动识别的边框的颜色obj.EditBorderColor= self.EditBorderColor;  //文本输入的边框颜色obj.Transparent = self.Transparent;      //工具栏的透明度obj.SetSaveName = self.SaveName;                                   //设置保存时的开始文字obj.SetMagnifierLogoText = self.MagnifierLogoText;                      //设置放大镜上的LOGO字符   obj.SetWatermarkPictureTypeEx = self.WatermarkPictureType;                        //设置水印的类型 obj.SetWatermarkPicturePath = self.WatermarkPicturePath;                      //设置水印的路径 obj.SetWatermarkTextTypeEx=self.WatermarkTextType;                            //设置水印文字的类型 obj.SetWatermarkTextValue= self.WatermarkTextValue;                     //设置水印文字obj.MosaicType = self.MosaicType;          //设置马赛克的类型 obj.SetToolbarText = self.ToolTipText;obj.MoreInfo = this.MoreInfo;//以下是截图时传递的参数 obj.DefaultPath = defaultpath;obj.HideCurrentWindow = hideCurrWindow;obj.AutoCaptureFlag = autoCaptureFlag;obj.x = x;obj.y = y;obj.Width = width;obj.Height = height;return obj; } this.DoCapture = function(name, hide, AutoCapture, x, y, width, height){        if(self.IsNeedCustomizedProtocol()){return self.DoCaptureForCustomize(name, hide, AutoCapture, parseInt(x), parseInt(y), parseInt(width), parseInt(height));}if(!self.pluginValid()){return emCaptureFailed;}self.niuniuCapture().Capture(name, hide, AutoCapture, x, y, width, height);return emCaptureSuccess;            }this.InitNiuniuCapture = function(){self.LoadPlugin();setTimeout("captureObjSelf.InitWebSocketAndBindCallback();", 200);}this.InitWebSocketAndBindCallback = function(){if(!self.autoConnectAfterPageLoad || !self.IsNeedCustomizedProtocol()){return;}self.connectHost();}this.getNextPort = function(){//init port params flag//进行拆分处理 self.hostPort;var portArray = self.hostPort.split(",");if(portArray.length < 1){alert("服务端口为空");return 30101;}if(self.hostPortIndex < 0){self.hostPortIndex = 0;              }if(self.hostPortIndex > portArray.length - 1){self.hostPortIndex = portArray.length - 1;                }var nPort = parseInt(portArray[self.hostPortIndex]);self.hostPortIndex++;if(self.hostPortIndex > portArray.length - 1){self.hostPortIndex = 0;              }   return nPort;}this.connectHost = function(){if(self.NiuniuSocket != null){self.WriteLog("connectHost NiuniuSocket is not null, return.");return;}clearTimeout(self.TimeOutID);self.connectState = emConnecting;try{var wshosts = ['127.0.0.1', 'localhost'];for (var i in wshosts) {try{var host = "ws://127.0.0.1:" + self.getNextPort() + "/" + self.CaptureName;self.NiuniuSocket = new WebSocket(host);break;}catch(ee){var ggg= 0;}}//OutputLog('Socket Status: '+socket.readyState);self.NiuniuSocket.onopen = function(evt){                 self.NiuniuSocket.send('0' + self.SocketTimeStamp);self.WriteLog("NiuniuSocket.onopen.");clearTimeout(self.TimeOutID);}self.NiuniuSocket.onmessage = function(msg){var str = "";str = msg.data;var id  = str.substr(0, 1);var arg1 = str.substr(1);clearTimeout(self.TimeOutID);if(id == "0"){self.hostPortIndex--;//表示连接成功，此时应该提示可以截图了 self.connectState = emConnected;self.pluginLoaded();self.IsEverConnected = true;self.IsFirstConnect = false;if(self.IsWaitCustomizedCallBack){setTimeout("captureObjSelf.SendReadyRecvData();", 3);}self.WriteLog("connect sucess.");self.ReceivedEchoBack = true;clearInterval(self.TimeIntervalID);self.TimeIntervalID = setInterval("captureObjSelf.LoopEchoMessage()", 3000);}if(id == "1"){//解析消息 var _aoResult = eval("(" + arg1 + ")");self.ReceivedEchoBack = true;if(_aoResult.command == "echo"){                  self.WriteLog("received echo");return;}self.WriteLog("received capturedata.");if(_aoResult.command == "version"){self.WriteLog(_aoResult.Ver);self.VersionCallback(_aoResult.Ver);}else{self.OnCaptureFinishedEx(_aoResult.Type, _aoResult.x, _aoResult.y, _aoResult.Width, _aoResult.Height, _aoResult.Info, _aoResult.Content, _aoResult.LocalPath);                      }}                                                      }self.NiuniuSocket.onclose = function(evt){self.OnWebSocketError("self.NiuniuSocket.onclose." + evt.data);} self.NiuniuSocket.onerror = function (evt) {                    //self.OnWebSocketError("self.NiuniuSocket.onerror." + evt.data);};} catch(e){self.OnWebSocketError("connect exception." + e.message);}}this.WriteLog = function(txt){//写日志 try{console.log(txt);}catch(e){}}this.OnWebSocketError = function(type){        //如果不处于连接成功状态，说明不是断开连接，而是连接失败 var isConnectedFailed = false;if(self.connectState != emConnected){isConnectedFailed = true;}self.WriteLog(type);self.ReceivedEchoBack = false;self.connectState = emClosed;        if(self.NiuniuSocket != null){self.NiuniuSocket.close();}self.NiuniuSocket = null;clearTimeout(self.TimeOutID);clearInterval(self.TimeIntervalID);if(isConnectedFailed){if(self.IsFirstConnect){self.IsFirstConnect = false;if(self.OnConnectFailed != null){self.OnConnectFailed(false);   }return;}if(self.IsEverConnected){self.reconnectTryTime++;//通知连接连接断开if(self.reconnectTryTime > 3){self.IsEverConnected = false;self.reconnectTryTime = 0;if(self.OnConnectFailed != null){self.OnConnectFailed(true);    }           return;}}}self.TimeOutID = setTimeout("captureObjSelf.connectHost();", 800);}this.LoopEchoMessage = function(){if(!self.ReceivedEchoBack){self.OnWebSocketError("this.LoopEchoMessage, !self.ReceivedEchoBack");self.ReceivedEchoBack = false;clearInterval(self.TimeIntervalID);self.TimeIntervalID = setInterval("captureObjSelf.LoopEchoMessage()", 3000);return;}self.ReceivedEchoBack = false;clearTimeout(self.TimeOutID);if(self.connectState != emConnected){clearInterval(self.TimeIntervalID);return;}        var obj = new Object(); obj.command = "echo";self.NiuniuSocket.send("1" + encodeURIComponent( $.toJSON(obj)) );     }this.SendReadyRecvData = function(){self.WriteLog("SendReadyRecvData.");var obj = self.NewCaptureParamObject("", 0, 0, 0, 0, 0, 0);obj.CmdType = -1;self.NiuniuSocket.send("1" + encodeURIComponent( $.toJSON(obj)) );}this.DoCaptureForCustomize = function(name, hide, AutoCapture, x, y, width, height){var obj = self.NewCaptureParamObject(name, hide, AutoCapture, x, y, width, height);try{//启动客户端，或者通过websocket去发送数据   if(self.connectState == emConnected){var json = $.toJSON(obj);self.NiuniuSocket.send('1' + encodeURIComponent(json) );}else{//首次启动时，不支持水印，否则会过长 obj.SetWatermarkPicturePath = "";//obj.SetWatermarkTextValue = ""; var json = $.toJSON(obj);self.WriteLog(json.length);var newUrl = self.CaptureName + "://" + encodeURIComponent(json);self.WriteLog(newUrl.length);//启动客户端  $('#startCaptureFrame').attr('src', newUrl);self.IsWaitCustomizedCallBack = true;self.connectHost();return emCaptureUnknown;}return emCaptureSuccess;}catch(e){alert(e.message);}  return emCaptureUnknown;       }this.IsNeedCustomizedProtocol = function(){if(isMacintosh()){return true;}if(!self.useCustomizedProtoco){return false;}if(self.pluginValid()){return false;}try{var agent = window.navigator.userAgent.toLowerCase();            var isQQBrowser = agent.indexOf("qqbrowser") != -1;//if(isQQBrowser)//{//    return false;//}var isUBrowser = agent.indexOf("ubrowser") != -1;if(isUBrowser){return false;}var isChrome = agent.indexOf("chrome") != -1;if(isChrome){if(chrome&&chrome.runtime){return true;}}//如果是firefox 且在50版本以上，则需要  var brow=$.browser;if(brow.mozilla){return true;}var isEdge = agent.indexOf("edge") != -1;if(isEdge){return true;}return false;}catch(e){}return false;    }this.GetVersion = function(){if(self.IsNeedCustomizedProtocol()){if(self.connectState != emConnected){return;}       var obj = new Object(); obj.command = "version";self.NiuniuSocket.send("1" + encodeURIComponent( $.toJSON(obj)) );return;}if(!self.pluginValid()){return;}var verSion = self.niuniuCapture().GetVersion();self.VersionCallback(verSion);self.WriteLog(verSion);}
}

　　capturewrapper.js

var savedPictureContent = '';
var extendName = '';
var captureObj = null;
var downloadUrl = 'http://www.ggniu.cn/download/CaptureInstall.exe';/*
用于初始化牛牛截图控件，此函数需要在页面加载完成后立即调用
在此函数中，您可以设置相关的截图的UI控制，如，画笔大小、边框颜色等等 【这部分信息在niuniucapture.js中也有默认值，直接修改默认值也可 】
*/
function Init()
{if(isMacintosh()){downloadUrl = 'http://www.ggniu.cn/download/CaptureInstall.dmg';}captureObj = new NiuniuCaptureObject();captureObj.NiuniuAuthKey = "niuniu";//此处可以设置相关参数captureObj.TrackColor = rgb2value(255, 0, 0);captureObj.EditBorderColor = rgb2value(0, 0, 255);//设置工具栏的TOOLTIP//captureObj.ToolTipText = "tipRectangle|tipCircle|tipArrow|tipBrush|tipGlitter|tipMosaic|tipText|tipUndo|tipSave|tipCancel|tipFinish|Finish";//设置控件加载完成以及截图完成的回调函数captureObj.FinishedCallback = OnCaptureFinishedCallback;captureObj.PluginLoadedCallback = PluginLoadedCallback;captureObj.VersionCallback = VersionCallback;//初始化控件captureObj.InitNiuniuCapture();
}//用于返回控件的版本号
function VersionCallback(ver)
{//captureObj.Version;//可以在此根据最新的版本号与控件返回的版本号对比，决定是否要提示升级  //alert(ver);
}
/*
当控件成功加载后回调的的函数，您可以在此控制相应的UI显示
*/
function PluginLoadedCallback(success)
{if(success){$('#info').html('');$('#imgshow').hide();$('#imgshow').attr('src', "./image/loading.gif?v=1");$('#btnReload').hide();$('#btnCapture').show();}
}//根据是否是Chrome新版本来控制下载不同的控件安装包
function ShowDownLoad()
{$('#info').html('如果超过5秒无响应，请点此<a target="_blank" href="' + downloadUrl + '" + date.getMinutes() + date.getSeconds()">安装</a>');
}/*
当提示安装控件后，需要重新加载控件来使用截图；
也有部分是需要刷新浏览器的
*/
function ReloadPlugin()
{captureObj.LoadPlugin();$('#btnReload').hide();$('#btnCapture').show();if(captureObj.pluginValid()){$('#downloadNotice').hide();$('#info').html("截图控件已经安装完毕，您可以进行截图了。");}else{var browserInfo = "查看控件是否被浏览器阻止，或通过浏览器设置中的加载项查看NiuniuCapture是否加载并正常运行";$('#info').html('截图控件未能识别到，请按如下步骤检查:<br/>1. 确定您已经下载控件安装包并正常安装 <br/>2. ' + browserInfo+ '<br/>3. 刷新页面或重新启动浏览器试下<br/>4. 如果仍旧不能截图，出大招吧：'+ '<a target="_blank" style="color:#ff0000;" class="btn" href="http://shang.qq.com/wpa/qunwpa?idkey=a9dab7a14df03d19a2833e6b5f17a33639027d06213cf61bdb7554b04492b6e5">一键加群求助</a>');}
}/*
截图入口函数，用于控制UI标签的显示
*/
function StartCapture()
{$('#imgshow').hide();$('#imgshow').attr('src', "./image/loading.gif?v=1");var captureRet = Capture();//从返回值来解析显示if(captureRet == emCaptureFailed){ShowDownLoad();}else if(captureRet == emCaptureUnknown){$('#info').html('正在截图中, 如果超过5秒无响应，请点此<a target="_blank" href="' + downloadUrl + '" + date.getMinutes() + date.getSeconds()">安装</a>');}
}/*
此函数是根据在测试页面上的不同选项来进行截图，在实际应用中，您只需要根据您实际需要的截图模式，传入相应的参数即可
*/
function Capture()
{var defaultName = "1.jpg"; //此处为了防止上传的数据过大，建议使用JPG格式var hideFlag = $("#hideCurrent").attr("checked")=="checked" ? 1 : 0;var autoFlag = $("#captureselectSize").attr("checked")=="checked" ? 1 : 0;var captureRet = true;if(autoFlag == 0){return captureObj.DoCapture("1.jpg", hideFlag, 0, 0, 0, 0, 0);}else{autoFlag = $('#getimagefromclipboard').is(':checked') ? 4 : 1;if(autoFlag == 4){return captureObj.DoCapture("", 0, 4, 0, 0, 0, 0);}autoFlag = $('#showprewindow').is(':checked') ? 3 : 1;if(autoFlag == 3){//此时如果x, y, width, height全为0，则表示预截图窗口点击“开始截图”时，手工先把区域//x, y, width, height全为1，则表示预截图窗口点击“开始截图”时，自动截取整个桌面//其他情况，则自动截取 x, y, width, height 指定的区域return captureObj.DoCapture("1.jpg", hideFlag, 3, 0, 0, 0, 0);}autoFlag = $('#fullscreen').is(':checked') ? 2 : 1;if(autoFlag == 2){return captureObj.DoCapture("1.jpg", hideFlag, 2, 0, 0, 0, 0);}else{return captureObj.DoCapture("1.jpg", hideFlag, 1, $('#xpos').val(), $('#ypos').val(), $('#width').val(), $('#height').val());}}
}/*
此处是截图后的回调函数，用于将截图的详细信息反馈回来，你需要调整此函数，完成图像数据的传输与显示
*/
function OnCaptureFinishedCallback(type, x, y, width, height, info, content,localpath)
{if(type < 0){//需要重新安装控件ShowDownLoad();return;}$('#show').hide();switch(type){case 1:{$('#info').html('截图完成： x:' + x + ',y:' + y + ',widht:' + width + ',height:' + height);UploadCaptureData(content, localpath);break;}case 2:{$('#info').html('您取消了截图');break;}case 3:{$('#info').html('您保存了截图到本地： x:' + x + ',y:' + y + ',widht:' + width + ',height:' + height);UploadCaptureData(content, localpath);break;}case 4:{if(info =='0'){$('#info').html('从剪贴板获取到了截图： ' + localpath);UploadCaptureData(content, localpath);}else{$('#info').html('从剪贴板获取图片失败。');}break;}}
}//控制上传
function UploadCaptureData(content, localpath)
{savedPictureContent = content;//获取图片的扩展名var pos = localpath.lastIndexOf('.');extendName = localpath.substr(pos + 1);$('#show').html('截图已经完成，请点击');$('#show').show();var autoUpload = $("#autoupload").attr("checked")=="checked" ? 1 : 0;if(autoUpload){UploadData();}else{$('#btnUpload').show();}
}/*
实际上传图像数据的函数，此处主要是将BASE64的图像数据，通过AJAX的方式POST到服务器保存成文件，并且显示在页面上
*/
function UploadData()
{$('#show').html('截图完成，正在上传，请稍后...');$('#btnUpload').hide();//上传的数据除了图片外，还可以包含自己需要传递的参数var data = "userid=test111&extendname=" + extendName + "&picdata=" + encodeURIComponent(savedPictureContent);$.ajax({type: "POST",url: "./upload.ashx",dataType: "json",data: data,success: function (obj) {if(obj.code==0){$('#show').html('上传成功，图片地址：' + obj.info);$('#imgshow').show();$('#imgshow').attr('src', obj.info);}else{$('#show').html('上传失败 :' + obj.info);}},error : function(){$('#show').html('由于网络原因，上传失败。'); }});
}function TestSetWatermarkPicture()
{captureObj.SetWatermarkPicture("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");
}

　　jquery.josn.js

(function($){var escapeable=/["\\\x00-\x1f\x7f-\x9f]/g,meta={'\b':'\\b','\t':'\\t','\n':'\\n','\f':'\\f','\r':'\\r','"':'\\"','\\':'\\\\'};$.toJSON=typeof JSON==='object'&&JSON.stringify?JSON.stringify:function(o){if(o===null){return'null';}
var type=typeof o;if(type==='undefined'){return undefined;}
if(type==='number'||type==='boolean'){return''+o;}
if(type==='string'){return $.quoteString(o);}
if(type==='object'){if(typeof o.toJSON==='function'){return $.toJSON(o.toJSON());}
if(o.constructor===Date){var month=o.getUTCMonth()+1,day=o.getUTCDate(),year=o.getUTCFullYear(),hours=o.getUTCHours(),minutes=o.getUTCMinutes(),seconds=o.getUTCSeconds(),milli=o.getUTCMilliseconds();if(month<10){month='0'+month;}
if(day<10){day='0'+day;}
if(hours<10){hours='0'+hours;}
if(minutes<10){minutes='0'+minutes;}
if(seconds<10){seconds='0'+seconds;}
if(milli<100){milli='0'+milli;}
if(milli<10){milli='0'+milli;}
return'"'+year+'-'+month+'-'+day+'T'+
hours+':'+minutes+':'+seconds+'.'+milli+'Z"';}
if(o.constructor===Array){var ret=[];for(var i=0;i<o.length;i++){ret.push($.toJSON(o[i])||'null');}
return'['+ret.join(',')+']';}
var name,val,pairs=[];for(var k in o){type=typeof k;if(type==='number'){name='"'+k+'"';}else if(type==='string'){name=$.quoteString(k);}else{continue;}
type=typeof o[k];if(type==='function'||type==='undefined'){continue;}
val=$.toJSON(o[k]);pairs.push(name+':'+val);}
return'{'+pairs.join(',')+'}';}};$.evalJSON=typeof JSON==='object'&&JSON.parse?JSON.parse:function(src){return eval('('+src+')');};$.secureEvalJSON=typeof JSON==='object'&&JSON.parse?JSON.parse:function(src){var filtered=src.replace(/\\["\\\/bfnrtu]/g,'@').replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g,']').replace(/(?:^|:|,)(?:\s*\[)+/g,'');if(/^[\],:{}\s]*$/.test(filtered)){return eval('('+src+')');}else{throw new SyntaxError('Error parsing JSON, source is not valid.');}};$.quoteString=function(string){if(string.match(escapeable)){return'"'+string.replace(escapeable,function(a){var c=meta[a];if(typeof c==='string'){return c;}
c=a.charCodeAt();return'\\u00'+Math.floor(c/16).toString(16)+(c%16).toString(16);})+'"';}
return'"'+string+'"';};})(jQuery);

在页面执行下就ok了，

<script>Init()</script>