On the first loop iteration, there is no backing store for tasks, so
It’s also possible to abandon the threshold matrix altogether and instead calculate a value for every pixel coordinate at runtime. If the function is simple enough this can be a good and efficient way to break up patterns and create interesting textures.
，更多细节参见WPS下载最新地址
CREATE TABLE IF NOT EXISTS items (，推荐阅读搜狗输入法下载获取更多信息
Maciej Piętowski