wx.canvasToTempFilePath是怎么了？

<canvas id=“myCanvas” canvas-id=“myCanvas”/>

<view @tap=“getTempFilePath”>保存图片</view>

getTempFilePath() {

    console.log(

0

)

    wx.canvasToTempFilePath({

        canvasId: ‘myCanvas’,

        success: res => {

        console.log(‘res’, res)

        },

        fail: err => {

        console.log(‘err’, err)

        },

        complete: () => {

        console.log(‘complete’)

        }

    })

}

只能输出0. wx.canvasToTempFilePath这个api根本没有被调用？？？

ps:

    基础库： 1.6.0

    微信开发者工具： 1.01.171019