canvasToTempFilePath

saveImageToPhotosAlbum

drawImage(src) {
            let byclear = this.data.byclear;
            let ctx = wx.createCanvasContext('canvasPoster', this)
            ctx.drawImage(this.data.src, 0, 0, 601 * byclear, 809 * byclear)
            wx.getImageInfo({
                src: src,
                success(res) {
                    console.log(res);
                    ctx.drawImage(res.path, 40 * byclear, 849 * byclear, 120 * byclear, 120 * byclear)
                }
            })
            
            ctx.setFontSize(14)
            ctx.fillText('xxxx', 240 * byclear, 869 * byclear)
            ctx.setFontSize(12)
            ctx.setFillStyle('#ffdc06')
            ctx.setTextBaseline('bottom')
            ctx.fillText('长按保存图片分享', 240 * byclear, 949 * byclear)
            ctx.draw()
            
        },

        createQRCode() {
            Api.UserApi.createQRCode({
                page: 'pages/index/index',
                scene: '123'
            }).then(res => {
                const fsm = wx.getFileSystemManager();
                const buffer = wx.base64ToArrayBuffer(res);
                const fileName = wx.env.USER_DATA_PATH + '/share_img.jpg'
                fsm.writeFileSync(fileName, buffer, 'binary')
                this.drawImage(fileName)
            })
        },

        saveImg() {
            wx.canvasToTempFilePath({
                canvasId: 'canvasPoster',
                success: (res) => {
                    wx.saveImageToPhotosAlbum({
                        filePath: res.tempFilePath,
                        success: (result) => {
                            wx.showToast({
                                title: '海报已保存，快去分享给好友吧。',
                                icon: 'none'
                            })
                        }
                    })
                },
                fail(err) {
                    console.log(err)
                }
            }, this)

        },

远程图片canvas无法渲染

保存到相册下半部分黑色