blocks|key|1553290|text|来自此文档页|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1553291|AnsiString结构包含一个32位长度指示器、一个32位参考计数、一个16位数据长度，指示每个字符的字节数，以及一个16位代码页。|blockquote|1553292|因此，AnsiString不仅仅是一个指向一个字符数组的指针--它是一个指向一种特殊结构的指针，它编码了一组信息。|style|CODE|1553293|但是，.NET的P/Invoke机器将传递一个指向字符数组的指针。德尔福将尝试将其解释为指向其特殊AnsiString结构的指针，而事情不会顺利进行。|1553294|我认为您将很难在互操作中使用AnsiString。最好选择一个.NET和Delphi都知道的字符串类型。如果您需要将其转换为AnsiString，请在德尔菲中这样做。|1553295|entityMap|0|LINK|mutability|MUTABLE|url|https://docwiki.embarcadero.com/RADStudio/Sydney/en/String_Types_(Delphi))^0|2|4|0|0|0|3|A|0|0|E|A|1Q|A|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|C|$]]|$1|G|3|H|5|6|7|11|8|@$A|12|B|13|I|J]]|9|@]|C|$]]|$1|K|3|L|5|6|7|14|8|@]|9|@]|C|$]]|$1|M|3|N|5|6|7|15|8|@$A|16|B|17|I|J]|$A|18|B|19|I|J]]|9|@]|C|$]]|$1|O|3|-4|5|6|7|1A|8|@]|9|@]|C|$]]]|P|$Q|$5|R|S|T|C|$U|V]]]]

From <a href="https://docwiki.embarcadero.com/RADStudio/Sydney/en/String_Types_(Delphi)" rel="nofollow noreferrer">this docs page</a>:
<blockquote>
The AnsiString structure contains a 32-bit length indicator, a 32-bit reference count, a 16-bit data length indicating the number of bytes per character, and a 16-bit code page.
</blockquote>
So an <code>AnsiString</code> isn't simply a pointer to an array of characters -- it's a pointer to a special structure which encodes a bunch of information.
However, .NET's P/Invoke machinery is going to pass a pointer to an array of characters. Delphi is going to try and interpret that as a pointer to its special AnsiString structure, and things aren't going to go well.
I think you're going to have a hard time using <code>AnsiString</code> in interop. You're better off choosing a string type which both .NET and Delphi know about. If you then need to convert that to <code>AnsiString</code>, do that in Delphi.

blocks|key|556911|text|将Delphi函数更改为|type|unstyled|depth|inlineStyleRanges|entityRanges|data|556912|procedure+Encrypt(Source,+Key,+OutPut:+PAnsiChar;+OutputLength:+Integer);+stdcall;|code-block|syntax|javascript|556913|才能让这个代码正常工作。|556914|您可能还应该设置长度参数IN/OUT，以便调用方能够在调用返回时调整字符串生成器对象的大小。这也将允许被调用方向调用方发出任何错误信号，这是当前设计中的另一个缺陷。|556915|我还必须说，使用AnsiString作为字节数组会导致失败。该是你开始加密的时候了。如果您有文本，然后将其编码为具有特定编码的字节数组，通常这意味着UTF-8。然后将该字节数组加密为另一个字节数组。|offset|length|style|CODE|556916|entityMap^0|0|0|0|0|8|A|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|V|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|W|8|@$M|X|N|Y|O|P]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

Change the Delphi function to
<pre><code>procedure Encrypt(Source, Key, OutPut: PAnsiChar; OutputLength: Integer); stdcall;
</code></pre>
in order to make this code work.
You should probably also make the length argument IN/OUT so that the caller can resize the string builder object once the call returns. That would also allow the callee to signal any errors to the caller, another flaw in your current design.
I must also say that using <code>AnsiString</code> as a byte array is a recipe for failure. It's high time you started doing encryption right. If you have text, then encode it as a byte array with a specific encoding, usually this means UTF-8. Then encrypt that byte array to another byte array.

I am trying to separate an encryption function from our legacy code to a dll which I can call from C#, but I am having issues getting it to work and I keep getting access violations when calling the dll.
I am not sure where the AV happens because delphi has a hard time hitting my breakpoints when the dll is attached to another process.
I got it to work yesterday using David Heffernan's answer here: <a href="https://stackoverflow.com/questions/16170360/returning-a-string-from-delphi-dll-to-c-sharp-caller-in-64-bit">Returning a string from delphi dll to C# caller in 64 bit</a>
But my success was short-lived as I changed the string parameters to regular <code>string</code>'s (delphi) saw it didn't work and changed them back to to <code>AnsiString</code> (our encryption routine expects Ansi). Since I changed these param types. I have not been able to get it to work again.
Here is my Delphi Code:
<pre class="lang-pascal prettyprint-override"><code>procedure Encrypt(const Source: AnsiString; const Key: AnsiString; var OutPut:PAnsiChar; const OutputLength: Integer);
var
 EncryptedString, EncodedString: AnsiString;
begin
 EncryptedString := Crypt(Source, Key);
 EncodedString := Encode(EncryptedString);
 if Length(EncodedString) &lt;= OutputLength then
 System.AnsiStrings.StrPCopy(Output, EncodedString);
end;

exports
 Encrypt;
</code></pre>
My C# caller:
<pre class="lang-cs prettyprint-override"><code>[DllImport(&quot;AsmEncrypt.dll&quot;, CharSet = CharSet.Ansi)]
public static extern void Encrypt(string password, string key, StringBuilder output, int outputlength);
// using like this:
Encrypt(credentials.Password, myKey, str, str.Capacity);

</code></pre>
My best bet right now is that I've goofed some of the arguments to the dll since it seems to crash before it reaches an <code>OutputDebugStr()</code> I had put on first line of <code>Encrypt()</code>
All help will be greatly appreciated

Returning string from delphi dll to c#

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我正在尝试将一个加密函数从我们的遗留代码中分离到一个dll中，我可以从C#中调用这个dll，但是我在使它正常工作时遇到了问题，并且在调用dll时一直存在访问冲突。我不知道AV在哪里发生，因为delphi在dll附加到另一个进程时很难击中我的断点。我昨天用大卫·赫弗南( David )的答案--  --让它工作了，但我的...

问从delphi返回字符串到c#
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