在使用getDataURL()的时候总是报错

TypeError: this.getRenderedCanvas(...).toDataURL is not a function

    at kd.Pd.getDataURL

    at Function.<anonymous> (index.js? [sm]:1754)

    at :48286/appservice/<setTimeout callback function>

    at VM902 WAService.js:2

    at VM902 WAService.js:2