titleNView 自定义按钮上显示不出字体图标，一直显示X

var webview = plus.webview.create('index.html', 'index.html_id',   
                    {  
                        scrollIndicator:'none',   
                        titleNView:   
                        {  

                            backgroundColor: 'rgb(247,247,247)',  
                            titleText: '平台',  
                            titleColor: '#285ab4',  
                            splitLine:{color:'rgba(210,210,210,0.5)'},  
                            autoBackButton: false,  
                            buttons:  
                            [  
                                {  
                                    text: '\ue601',//跳转过去一直显示X，显示不出图标  
                                    color:"black",  
                                    float: 'right',  
                                    fontSrc:"fonts/iconfont.ttf",  
                                    onclick: function()  
                                    {  

                                    }  
                                }  
                            ]  
                        }  
                    });  

                    webview.show("pop-in");