微信小程序canvas生成图片并保存本地

  createImage: function(){
    let imageWidth = this.data.imageWidth,
      imageHeight = this.data.imageHeight;
 
    wx.canvasToTempFilePath({     //将canvas生成图片
      canvasId: 'gameCanvas',
      x: 0,
      y: 0,
      width: imageWidth,
      height: imageHeight,
      destWidth: imageWidth,     //截取canvas的宽度
      destHeight: imageHeight,   //截取canvas的高度
      success: function (res) {
        wx.saveImageToPhotosAlbum({  //保存图片到相册
          filePath: res.tempFilePath,
          success: function () {
            wx.showToast({
              title: "生成图片成功！",
              duration: 2000
            })
          }
        })
      }
    })
  }