Component中canvas的draw回调函数无法进入

• 当前 Bug 的表现（可附上截图）

    Component中canvas的draw回调函数无法进入， 只打印了1

• 预期表现

    回调函数会进入,并打印1 和 2

• 复现路径

见Demo

• 提供一个最简复现 Demo

    const context = wx.createCanvasContext(‘xx_canvas’);

    context.setFillStyle(‘red’)

    context.fillRect(10, 10, 150, 100)

    console.log(“1”);

    context.draw(false, function(e) {

        console.log(“2”);

        // do something…

        wx.canvasToTempFilePath({

            x: 0,

            y: 0,

            width: 650,

            height: 960,

            canvasId: ‘xx_canvas’,

            fileType: ‘png’,

            success: function (res) {

                let pic = res.tempFilePath;

                console.log(pic);

                wx.previewImage({

                    urls: [res.tempFilePath],

                })

            }

        });

    })

只打印了“1”，未打印2.