wpsjs 添加表格水印

et表格和wps文档都可以使用，解决et表格api 无法设定水印的问题

var WatermarkInfo = {"visibleStatus":1,"watermarkText":"水印测试","opacity":0.5,"font_size":30}

wps.Application.GetApplicationEx().SetWatermarkInfo(JSON.stringify(WatermarkInfo));