https://leafcxy.github.io/tags/bug/Recent content in Bug on LeafCxy's BlogHugozh-cnSat, 19 Jul 2025 02:46:20 +0000https://leafcxy.github.io/posts/2025-07-19-1/Sat, 19 Jul 2025 02:46:20 +0000https://leafcxy.github.io/posts/2025-07-19-1/<p>用 ILSPY 或者 .NET Reflector 、dnspy 等反编译出来之后 <PrivateImplementationDetails> 文件由于语法不符合已经被丢弃了，</p> <p>所以在反编译工具里面找到这个类，手动复制出来，新建一个类，把尖括号等去掉，方法就只保留 ComputeStringHash 方法就行了。</p> <p>再在报错的地方也把尖括号去掉。</p> <p>这个方法原本是一个string类型的switch，switch本身就要计算hash来判断，但是反编译工具对这个的解析出了问题，</p> <!-- more --> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-csharp" data-lang="csharp"><span style="display:flex;"><span><span style="color:#a6e22e">[CompilerGenerated]</span> </span></span><span style="display:flex;"><span><span style="color:#66d9ef">internal</span> <span style="color:#66d9ef">sealed</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">PrivateImplementationDetails</span> </span></span><span style="display:flex;"><span>{ </span></span><span style="display:flex;"><span> <span style="color:#66d9ef">internal</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">uint</span> ComputeStringHash(<span style="color:#66d9ef">string</span> s) </span></span><span style="display:flex;"><span> { </span></span><span style="display:flex;"><span> <span style="color:#66d9ef">uint</span> num = <span style="color:#ae81ff">0</span>; </span></span><span style="display:flex;"><span> <span style="color:#66d9ef">if</span>(s != <span style="color:#66d9ef">null</span>) </span></span><span style="display:flex;"><span> { </span></span><span style="display:flex;"><span> num = <span style="color:#ae81ff">2166136261</span>U; </span></span><span style="display:flex;"><span> <span style="color:#66d9ef">for</span>(<span style="color:#66d9ef">int</span> i=<span style="color:#ae81ff">0</span>;i&lt;s.Length;i++) </span></span><span style="display:flex;"><span> { </span></span><span style="display:flex;"><span> num = ((<span style="color:#66d9ef">uint</span>)s[i] ^ num)*<span style="color:#ae81ff">16777619</span>U; </span></span><span style="display:flex;"><span> } </span></span><span style="display:flex;"><span> } </span></span><span style="display:flex;"><span> <span style="color:#66d9ef">return</span> num; </span></span><span style="display:flex;"><span> } </span></span><span style="display:flex;"><span>} </span></span></code></pre></div><p>重建类后测试 ComputeStringHash(&ldquo;link&rdquo;)最后的结果就是 232457833 ，</p> <p>如果判断条件不多的话其实可以直接把这个数字判断全部删掉，重写switch或者if都可以。如果判断条件很多懒得弄就自建PrivateImplementationDetails是最简单的</p>