图片base64
var base64data = await that.imgToBase64(key)
listdata.fileBase64 = base64data.replace(/^data:image\/\w+;base64,/, "")
eventFiles.push(listdata)
音频base64
that.audio.replace(/^data:audio\/\w+;base64,/, "")
视频base64
base64data.replace(/^data:video\/\w+;base64,/, "")