added bg

src/adapter/adapter.js

 utils.extend( KityMinder, function () {
     var _kityminderUI = {},
-        _kityminderToolbarUI ={},
+        _kityminderToolbarUI = {},
         _activeWidget = null,
         _widgetData = {},
         _widgetCallBack = {};
@@ -15,9 +15,9 @@ utils.extend( KityMinder, function () {
                 _kityminderToolbarUI[ name ] = fn;
             } )
         },
-        loadUI:function(km){
+        loadUI: function ( km ) {
             utils.each( _kityminderUI, function ( i, fn ) {
-                fn.call(km)
+                fn.call( km )
             } )
         },
         _createUI: function ( id ) {
@@ -68,7 +68,7 @@ utils.extend( KityMinder, function () {
             this._createStatusbar( containers.$statusbar, km );
             km.$container = containers.$container;
 
-            this.loadUI(km);
+            this.loadUI( km );
             return km.fire( 'interactchange' );
         },
         registerWidget: function ( name, pro, cb ) {

src/adapter/saveto.js

@@ -32,15 +32,16 @@ KM.registerToolbarUI( 'saveto', function ( name ) {
     comboboxWidget.on( 'comboboxselect', function ( evt, res ) {
         if ( res.value === "png" ) {
             var svghtml = $( "#kityminder .kmui-editor-body" ).html();
-            var rootBox = me.getRoot().getRenderContainer().getRenderBox();
+            var bgImg = $( "#kityminder .kmui-editor-body" ).css( "backgroundImage" ).replace( /"/g, "" ).replace( /url\(|\)$/ig, "" );
+            var renderBox = me.getRenderContainer().getRenderBox();
             var svg = $( svghtml ).attr( {
-                width: rootBox.x + me.getRenderContainer().getWidth() + 20,
-                height: rootBox.y + me.getRenderContainer().getHeight() + 20,
+                width: renderBox.x + me.getRenderContainer().getWidth(),
+                height: renderBox.y + me.getRenderContainer().getHeight(),
                 viewBox: null
             } );
             var div = $( "<div></div>" ).append( svg );
             svghtml = div.html();
-            var canvas = $( '<canvas style="border:2px solid black;" width="' + svg.attr( "width" ) + '" height="' + svg.attr( "height" ) + '"></canvas>' );
+            var canvas = $( '<canvas width="' + renderBox.width + '" height="' + renderBox.height + '"></canvas>' );
             var ctx = canvas[ 0 ].getContext( "2d" );
             var DOMURL = self.URL || self.webkitURL || self;
             var img = new Image();
@@ -49,30 +50,37 @@ KM.registerToolbarUI( 'saveto', function ( name ) {
             } );
             var url = DOMURL.createObjectURL( svg );
             img.onload = function () {
-                ctx.drawImage( img, 0, 0 );
-                DOMURL.revokeObjectURL( url );
-                var type = 'png';
-                var imgData = canvas[ 0 ].toDataURL( type );
-                var _fixType = function ( type ) {
-                    type = type.toLowerCase().replace( /jpg/i, 'jpeg' );
-                    var r = type.match( /png|jpeg|bmp|gif/ )[ 0 ];
-                    return 'image/' + r;
-                };
-                imgData = imgData.replace( _fixType( type ), 'image/octet-stream' );
-                var saveFile = function ( data, filename ) {
-                    var save_link = document.createElementNS( 'http://www.w3.org/1999/xhtml', 'a' );
-                    save_link.href = data;
-                    save_link.download = filename;
+                var bgTexture = document.createElement( 'img' );
+                bgTexture.src = bgImg;
+                bgTexture.onload = function () {
+                    var bgfill = ctx.createPattern( bgTexture, "repeat" );
+                    ctx.fillStyle = bgfill;
+                    ctx.fillRect( 0, 0, renderBox.width, renderBox.height );
+                    ctx.drawImage( img, -renderBox.x, -renderBox.y );
+                    DOMURL.revokeObjectURL( url );
+                    var type = 'png';
+                    var imgData = canvas[ 0 ].toDataURL( type );
+                    var _fixType = function ( type ) {
+                        type = type.toLowerCase().replace( /jpg/i, 'jpeg' );
+                        var r = type.match( /png|jpeg|bmp|gif/ )[ 0 ];
+                        return 'image/' + r;
+                    };
+                    imgData = imgData.replace( _fixType( type ), 'image/octet-stream' );
+                    var saveFile = function ( data, filename ) {
+                        var save_link = document.createElementNS( 'http://www.w3.org/1999/xhtml', 'a' );
+                        save_link.href = data;
+                        save_link.download = filename;
 
-                    var event = document.createEvent( 'MouseEvents' );
-                    event.initMouseEvent( 'click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null );
-                    save_link.dispatchEvent( event );
-                };
+                        var event = document.createEvent( 'MouseEvents' );
+                        event.initMouseEvent( 'click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null );
+                        save_link.dispatchEvent( event );
+                    };
 
-                // 下载后的问题名
-                var filename = 'kityminder_' + ( new Date() ).getTime() + '.' + type;
-                // download
-                saveFile( imgData, filename );
+                    // 下载后的文件名
+                    var filename = 'kityminder_' + ( new Date() ).getTime() + '.' + type;
+                    // download
+                    saveFile( imgData, filename );
+                };
             };
             img.src = url;
             return "png";