How can i delete resources which i create form editor code?

i use WWW load a texture form my streamingAssets path,and i create a sprite in editor code ,then i give this texture to senses object of sprite render, i think it will destroy when i close the scenes,but it is not.So,i 'try to set sprite of spriterender object value is null ,but the sprite resources i created before still save in .unity file,i don’t know how to delete this resource, can any one help me?

You have to Destroy() the texture when you don’t need it anymore. If you want to destroy the texture from editor code you have to use DestroyImmediate.

Have a look at the Class Hierarchy. Everything that is derived from UnityEngine.Object can be destroyed with Destroy / DestroyImmediate. Note that you should be careful what you destroy during edit time. Those actions are permanent and may not be reversable.