wx.canvasToTempFilePath真机不执行是什么原因?

context.draw(）第一个参数为true的时候，回调里面 wx.canvasToTempFilePath真机不执行;但是在模拟器中一切正常。并且配置了服务器域名

context.draw(true, () =>         setTimeout(() =>           wx.canvasToTempFilePath({             canvasId: 'canvas',             x: 0,             y: 0,             width: canvasw,             height: canvash,             fileType: 'png',             success: function (res) {                            var tempFilePath = res.tempFilePath;               _this.setData({                 src: tempFilePath,                 modalVisible: false               })               wx.hideToast()               _this.triggerEvent('callBackUrl', { code: 'success', url: tempFilePath})             },           }, _this)         , 100)       )