在C＃中从计算机内存中删除字符串

Question

I have to work with string because it has all the functions I have like check any letters of it, substring and so on. After used string I need to delete it from computer memory. I have already read about SecureString but I can not work with it because it has not a lot of functions.

Can anyone help me how to delete string from memory? How can I solve it?

Answer 1

Both answers should have provided the correct answer for most cases, but in case your string value is considerably critical that you must remove it from the memory after using it, your best bet would be to use SecureString .

You have already stated that SecureString does not provide the methods you specifically need; in that case, you need to do some on your own. Luckily, .NET is open source and you can easily Copy-Paste the implementations you need from here . Make them as extensions of SecureString to use them.

Answer 2

As long as those a dynamic strings, not compiled literals - you don't need to worry about "deleting" them, Garbage Collector will do it for you. Strings are same as any other .net classes, so you don't need to manage memory they are allocating.

If you are worry about size of the memory your application takes at some periods of time - you can kindly force GC to collect all resources, that are not needed any more by calling System.GC.Collect() . But usually this is not needed.

Also be aware, that calling System.GC.Collect() doesn't mean garbage collection will start right away - it means that GC will schedule collection some time soon.

Answer 3

If you remove all references to the string, you can call System.GC.Collect() to force the Garbage Collector to run, although even then it's not guaranteed to run immediately, more like "Hey, GC, run as soon as you get the chance." And it's really not recommended at all. It can cause serious performance issues if you do it often.

If your string is really so critical that you don't even want it floating around in memory, SecureString really is your best bet. You'll just have to re-implement functions you need (like .SubString()) for it.