Const and readonly in. net

I am working overtime on Saturday. I can go later. When I get up in the morning, I suddenly think of the similarities and differences between const and readonly in. net. I once asked a candidate for an interview at the company when I was recruiting, but he gave me an explanation of the chinese meanings of the two words. Now there are some developers who have asked him to do the project, but there may be a lack of things.
Let me talk about the knowledge points here. Experience :
A knowledge point is used to get a piece of water at a time and practice it. Never forget.
Next, let's talk about the differences that I understand.
1. the const field can only be in Statement .
The readonly field can be found in Declaration or constructor . Therefore, the readonly field may have different values based on the constructors used.
2. the const field is Compile time Constant, while the readonly field can be used Runtime Constant.
3. Const Constant of the reference type. The possible values can only be string and null. .
Readonly can be Any Type
Note: : When modifying the reference type of readonly, it should be understood that the reference address cannot be modified, and the internal field of the referenced object can be changed. I often use readonly in projects to implement "Single-value mode ". For example, the "memory table" in the system"