c#中使用不安全代码(使用指针的代码)(国外英语资料)

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1、C#中使用不安全代码(使用指针的代码)Howtouseunsafecodeinc#(usingpointercode)ThereislittleneedtousePointersinc#,buttherearestillsomesituationsthatneedtobeused.Forexample,theuseofanunsafecontextthatallowsPointerstobeusedinthefollowingcasesiscorrect:ProcessingexistingstructuresondiskAhi

2、gh-levelCOMorplatforminvocationschemeinvolvingthestructureoftheinternalcontainingPointersPerformancekeycodeItisnotencouragedtouseanunsafecontextinothercases.Specifically,youshouldnotattempttowriteCcodeinC#usinganunsafecontext.Warningthatcodewritteninaninsecurecontext

3、cannotbevalidatedassecure,soitonlyexecuteswhenthecodeisfullytrusted.Inotherwords,youcan'texecuteunsecuredcodeinanuntrustedenvironment.Forexample,youcan'trununsecuredcodedirectlyfromtheInternet.Thistutorialincludesthefollowingexamples:Example1USESPointerstocopyabytear

4、ray.Example2showshowtoinvoketheWindowsReadFilefunction.Example3showshowtoprinttheWin32versionoftheexecutable.Example1ThefollowingexampleUSESapointertocopyabytearrayfromSRCtoDST.Compilethisexamplewiththe/unsafeoption.//fastcopy.Cs//it'sveryhardUsingSystem;TheclassTest

5、{//TheunsafekeywordallowstobeusedwithinThe//followingmethod:StaticunsafevoidCopy(byte[]SRC,intsrcIndex,Byte[]DST,intdstIndex,intcount{If(SRC==null

6、srcIndex<0

7、

8、DST==null

9、

10、dstIndex<0

11、

12、count<0{.ThrownewArgumentException();}IntsrcLen=SRC.length;IntdstLen=DST.If(srclen-sr

13、cindex

14、

15、dstLen-dstindex

16、ytes//integer(4bytes)atatime:For(intn=0;n

17、r(intI=0;I<100++I)A[I]=(byte)I;Copy(a,0,b,0,100);WriteLine("Thefirst10elementsare:")For(intI=0;I<10;++I)(b[I]+")WriteLine("");}}s