{"id":1748,"date":"2022-11-19T22:02:03","date_gmt":"2022-11-19T14:02:03","guid":{"rendered":"https:\/\/courtship.top\/?p=1748"},"modified":"2024-07-23T04:37:10","modified_gmt":"2024-07-22T20:37:10","slug":"%e8%99%9a%e5%87%bd%e6%95%b0%e7%9a%84vptr%e4%b8%8evtable","status":"publish","type":"post","link":"https:\/\/courtship.top\/index.php\/2022\/11\/19\/%e8%99%9a%e5%87%bd%e6%95%b0%e7%9a%84vptr%e4%b8%8evtable\/","title":{"rendered":"\u865a\u51fd\u6570vptr\uff0cvtable\u4e0e\u8fd0\u884c\u591a\u6001"},"content":{"rendered":"\n

\u624b\u673a\u4e0a\u6574\u7406\u7684\u4e0d\u591f\u8be6\u7ec6...\u5f53\u65f6\u88ab\u62f7\u6253\u7684\u5f88\u96be\u53d7\uff0c\u8fd8\u662f\u8981\u597d\u597d\u5b66\u4e0b\u5b66\u4e0b\u8fd9\u79cd\u57fa\u7840\u7684\u4e1c\u897f<\/p>\n\n\n\n

\u539f\u6587<\/a><\/p>\n\n\n\n

\u57fa\u7840\u7406\u8bba<\/h2>\n\n\n\n

vtable<\/h3>\n\n\n\n

\u4e3a\u4e86\u5b9e\u73b0\u865a\u51fd\u6570\uff0cC ++\u4f7f\u7528\u4e00\u79cd\u79f0\u4e3a\u865a\u62df\u8868<\/strong>\u7684\u7279\u6b8a\u5f62\u5f0f\u7684\u540e\u671f\u7ed1\u5b9a\u3002\u8be5\u865a\u62df\u8868\u662f\u7528\u4e8e\u89e3\u51b3\u5728\u52a8\u6001\/\u540e\u671f\u7ed1\u5b9a\u65b9\u5f0f\u7684\u51fd\u6570\u8c03\u7528\u51fd\u6570\u7684\u67e5\u627e\u8868<\/strong>\u3002<\/p>\n\n\n\n

\u865a\u62df\u8868\u6709\u65f6\u4f1a\u4f7f\u7528\u5176\u4ed6\u540d\u79f0\uff0c\u4f8b\u5982\u201cvtable\u201d\uff0c\u201c\u865a\u51fd\u6570\u8868\u201d\uff0c\u201c\u865a\u65b9\u6cd5\u8868\u201d\u6216\u201c\u8c03\u5ea6\u8868\u201d\u3002<\/p>\n\n\n\n

\u865a\u62df\u8868\u5b9e\u9645\u4e0a\u975e\u5e38\u7b80\u5355\uff0c\u867d\u7136\u7528\u6587\u5b57\u63cf\u8ff0\u6709\u70b9\u590d\u6742\u3002\u9996\u5148\uff0c\u6bcf\u4e2a\u4f7f\u7528\u865a\u51fd\u6570\u7684\u7c7b\uff08\u6216\u8005\u4ece\u4f7f\u7528\u865a\u51fd\u6570\u7684\u7c7b\u6d3e\u751f\uff09\u90fd\u6709\u81ea\u5df1\u7684\u865a\u62df\u8868<\/strong>\u3002\u8be5\u8868\u53ea\u662f\u7f16\u8bd1\u5668\u5728\u7f16\u8bd1\u65f6\u8bbe\u7f6e\u7684\u9759\u6001\u6570\u7ec4<\/strong>\u3002\u865a\u62df\u8868\u5305\u542b\u53ef\u7531\u7c7b\u7684\u5bf9\u8c61\u8c03\u7528\u7684\u6bcf\u4e2a\u865a\u51fd\u6570\u7684\u4e00\u4e2a\u6761\u76ee\u3002\u6b64\u8868\u4e2d\u7684\u6bcf\u4e2a\u6761\u76ee\u53ea\u662f\u4e00\u4e2a\u51fd\u6570\u6307\u9488<\/strong>\uff0c\u6307\u5411\u8be5\u7c7b\u53ef\u8bbf\u95ee\u7684\u6d3e\u751f\u51fd\u6570<\/strong>\u3002<\/p>\n\n\n\n

vptr<\/h3>\n\n\n\n

\u5176\u6b21\uff0c\u7f16\u8bd1\u5668\u8fd8\u4f1a\u6dfb\u52a0\u4e00\u4e2a\u9690\u85cf\u6307\u5411\u57fa\u7c7b\u7684\u6307\u9488<\/strong>\uff0c\u6211\u4eec\u79f0\u4e4b\u4e3avptr\u3002vptr\u4f1a\u5728\u521b\u5efa\u7c7b\u5b9e\u4f8b\u65f6\u81ea\u52a8\u8bbe\u7f6e\uff0c\u4ee5\u4fbf\u6307\u5411\u8be5\u7c7b\u7684\u865a\u62df\u8868\u3002\u4e0ethis\u6307\u9488\u4e0d\u540c\uff0cthis\u6307\u9488\u5b9e\u9645\u4e0a\u662f\u7f16\u8bd1\u5668\u7528\u6765\u89e3\u6790\u81ea\u5f15\u7528\u7684\u51fd\u6570\u53c2\u6570\uff0cvptr\u662f\u4e00\u4e2a\u771f\u6b63\u7684\u6307\u9488\u3002<\/p>\n\n\n\n

\u56e0\u6b64\uff0c\u5b83\u4f7f\u6bcf\u4e2a\u7c7b\u5bf9\u8c61\u7684\u5206\u914d\u4e00\u4e2a\u6307\u9488\u7684\u5927\u5c0f\u3002\u8fd9\u4e5f\u610f\u5473\u7740vptr\u7531\u6d3e\u751f\u7c7b\u7ee7\u627f<\/strong>\uff0c\u8fd9\u5f88\u91cd\u8981\u3002<\/p>\n\n\n\n

\u5b9e\u73b0\u4e0e\u5185\u90e8\u7ed3\u6784<\/h2>\n\n\n\n

C++\u7684\u52a8\u6001\u591a\u6001\u6027\u662f\u901a\u8fc7\u865a\u51fd\u6570\u6765\u5b9e\u73b0\u7684,\u901a\u8fc7virtual\u51fd\u6570\uff0c\u6307\u5411\u5b50\u7c7b\u7684\u57fa\u7c7b\u6307\u9488\u53ef\u4ee5\u8c03\u7528\u5b50\u7c7b\u7684\u51fd\u6570\u3002<\/strong><\/p>\n\n\n\n

\u5177\u4f53\u5b9e\u73b0\u770b\u539f\u6587<\/p>\n\n\n\n

\u5176\u8fc7\u7a0b\u4e3a\uff1a<\/p>\n\n\n\n

    \n
  • \u9996\u5148\u7a0b\u5e8f\u8bc6\u522b\u51fafun1()\u662f\u4e2a\u865a\u51fd\u6570<\/li>\n\n\n\n
  • \u5176\u6b21\u7a0b\u5e8f\u4f7f\u7528pt->vptr\u6765\u83b7\u53d6Derived\u7684\u865a\u62df\u8868<\/li>\n\n\n\n
  • \u7b2c\u4e09\uff0c\u5b83\u67e5\u627eDerived\u865a\u62df\u8868\u4e2d\u8c03\u7528\u54ea\u4e2a\u7248\u672c\u7684fun1()\u3002\u8fd9\u91cc\u5c31\u53ef\u4ee5\u53d1\u73b0\u8c03\u7528\u7684\u662fDerived::fun1()\u3002\u56e0\u6b64pt->fun1()\u88ab\u89e3\u6790\u4e3aDerived::fun1()!<\/li>\n<\/ul>\n\n\n\n

    \u8fd0\u884c\u591a\u6001<\/h2>\n\n\n\n

    \u865a\u51fd\u6570\u7684\u8c03\u7528\u53d6\u51b3\u4e8e\u6307\u5411\u6216\u8005\u5f15\u7528\u7684\u5bf9\u8c61\u7684\u7c7b\u578b\uff0c\u800c\u4e0d\u662f\u6307\u9488\u6216\u8005\u5f15\u7528\u81ea\u8eab\u7684\u7c7b\u578b\u3002<\/strong><\/p>\n\n\n\n

    \u9ed8\u8ba4\u53c2\u6570<\/h2>\n\n\n\n

    \u9ed8\u8ba4\u53c2\u6570\u662f\u9759\u6001\u7ed1\u5b9a\u7684\uff0c\u865a\u51fd\u6570\u662f\u52a8\u6001\u7ed1\u5b9a\u7684\u3002 \u9ed8\u8ba4\u53c2\u6570\u7684\u4f7f\u7528\u9700\u8981\u770b\u6307\u9488\u6216\u8005\u5f15\u7528\u672c\u8eab\u7684\u7c7b\u578b\uff08\u53cd\u8fc7\u6765\u4e86\uff09\uff0c\u800c\u4e0d\u662f\u5bf9\u8c61\u7684\u7c7b\u578b<\/strong>\u3002<\/p>\n\n\n\n

    (\u91cd\u8981)\u53ef\u4ee5\u4e0d\u53ef\u4ee5<\/h2>\n\n\n\n

    \u9759\u6001\u51fd\u6570\u53ef\u4ee5\u58f0\u660e\u4e3a\u865a\u51fd\u6570\u5417\uff1f<\/strong><\/h3>\n\n\n\n

    \u539f\u56e0\u4e3b\u8981\u6709\u4e24\u65b9\u9762\uff1a<\/p>\n\n\n\n

    \u9759\u6001\u51fd\u6570\u4e0d\u53ef\u4ee5\u58f0\u660e\u4e3a\u865a\u51fd\u6570\uff0c\u540c\u65f6\u4e5f\u4e0d\u80fd\u88abconst \u548c volatile\u5173\u952e\u5b57\u4fee\u9970<\/strong><\/p>\n\n\n\n

    static\u6210\u5458\u51fd\u6570\u4e0d\u5c5e\u4e8e\u4efb\u4f55\u7c7b\u5bf9\u8c61\u6216\u7c7b\u5b9e\u4f8b\uff0c\u6240\u4ee5\u5373\u4f7f\u7ed9\u6b64\u51fd\u6570\u52a0\u4e0avirutal\u4e5f\u662f\u6ca1\u6709\u4efb\u4f55\u610f\u4e49<\/p>\n\n\n\n

    \u865a\u51fd\u6570\u4f9d\u9760vptr\u548cvtable\u6765\u5904\u7406\u3002vptr\u662f\u4e00\u4e2a\u6307\u9488\uff0c\u5728\u7c7b\u7684\u6784\u9020\u51fd\u6570\u4e2d\u521b\u5efa\u751f\u6210\uff0c\u5e76\u4e14\u53ea\u80fd\u7528this\u6307\u9488\u6765\u8bbf\u95ee\u5b83\uff0c\u9759\u6001\u6210\u5458\u51fd\u6570\u6ca1\u6709this\u6307\u9488\uff0c\u6240\u4ee5\u65e0\u6cd5\u8bbf\u95eevptr\u3002<\/p>\n\n\n\n

    \u6784\u9020\u51fd\u6570\u53ef\u4ee5\u4e3a\u865a\u51fd\u6570\u5417\uff1f<\/strong><\/h3>\n\n\n\n

    \u6784\u9020\u51fd\u6570\u4e0d\u53ef\u4ee5\u58f0\u660e\u4e3a\u865a\u51fd\u6570\u3002\u540c\u65f6\u9664\u4e86inline|explicit\u4e4b\u5916\uff0c\u6784\u9020\u51fd\u6570\u4e0d\u5141\u8bb8\u4f7f\u7528\u5176\u5b83\u4efb\u4f55\u5173\u952e\u5b57\u3002<\/p>\n\n\n\n

    \u4e3a\u4ec0\u4e48\u6784\u9020\u51fd\u6570\u4e0d\u53ef\u4ee5\u4e3a\u865a\u51fd\u6570\uff1f<\/p>\n\n\n\n

    \u5c3d\u7ba1\u865a\u51fd\u6570\u8868vtable\u662f\u5728\u7f16\u8bd1\u9636\u6bb5\u5c31\u5df2\u7ecf\u5efa\u7acb\u7684\uff0c\u4f46\u6307\u5411\u865a\u51fd\u6570\u8868\u7684\u6307\u9488vptr\u662f\u5728\u8fd0\u884c\u9636\u6bb5\u5b9e\u4f8b\u5316\u5bf9\u8c61\u65f6\u624d\u4ea7\u751f\u7684\u3002 \u5982\u679c\u7c7b\u542b\u6709\u865a\u51fd\u6570\uff0c\u7f16\u8bd1\u5668\u4f1a\u5728\u6784\u9020\u51fd\u6570\u4e2d\u6dfb\u52a0\u4ee3\u7801\u6765\u521b\u5efavptr\u3002 \u95ee\u9898\u6765\u4e86\uff0c\u5982\u679c\u6784\u9020\u51fd\u6570\u662f\u865a\u7684\uff0c\u90a3\u4e48\u5b83\u9700\u8981vptr\u6765\u8bbf\u95eevtable\uff0c\u53ef\u8fd9\u4e2a\u65f6\u5019vptr\u8fd8\u6ca1\u4ea7\u751f\u3002 \u56e0\u6b64\uff0c\u6784\u9020\u51fd\u6570\u4e0d\u53ef\u4ee5\u4e3a\u865a\u51fd\u6570\u3002<\/p>\n\n\n\n

    \u6211\u4eec\u4e4b\u6240\u4ee5\u4f7f\u7528\u865a\u51fd\u6570\uff0c\u662f\u56e0\u4e3a\u9700\u8981\u5728\u4fe1\u606f\u4e0d\u5168\u7684\u60c5\u51b5\u4e0b\u8fdb\u884c\u591a\u6001\u8fd0\u884c\u3002\u800c\u6784\u9020\u51fd\u6570\u662f\u7528\u6765\u521d\u59cb\u5316\u5b9e\u4f8b\u7684\uff0c\u5b9e\u4f8b\u7684\u7c7b\u578b\u5fc5\u987b\u662f\u660e\u786e\u7684\u3002 \u56e0\u6b64\uff0c\u6784\u9020\u51fd\u6570\u6ca1\u6709\u5fc5\u8981\u88ab\u58f0\u660e\u4e3a\u865a\u51fd\u6570\u3002<\/p>\n\n\n\n

    \u6790\u6784\u51fd\u6570\u53ef\u4ee5\u4e3a\u865a\u51fd\u6570\u5417\uff1f<\/strong><\/h3>\n\n\n\n

    \u6790\u6784\u51fd\u6570\u53ef\u4ee5\u58f0\u660e\u4e3a\u865a\u51fd\u6570\u3002<\/p>\n\n\n\n

    \u5982\u679c\u6211\u4eec\u9700\u8981\u5220\u9664\u4e00\u4e2a\u6307\u5411\u6d3e\u751f\u7c7b\u7684\u57fa\u7c7b\u6307\u9488\u65f6\uff0c\u5e94\u8be5\u628a\u6790\u6784\u51fd\u6570\u58f0\u660e\u4e3a\u865a\u51fd\u6570\u3002 \u4e8b\u5b9e\u4e0a\uff0c\u53ea\u8981\u4e00\u4e2a\u7c7b\u6709\u53ef\u80fd\u4f1a\u88ab\u5176\u5b83\u7c7b\u6240\u7ee7\u627f\uff0c \u5c31\u5e94\u8be5\u58f0\u660e\u865a\u6790\u6784\u51fd\u6570(\u54ea\u6015\u8be5\u6790\u6784\u51fd\u6570\u4e0d\u6267\u884c\u4efb\u4f55\u64cd\u4f5c)\u3002<\/p>\n\n\n\n

    \u865a\u51fd\u6570\u53ef\u4ee5\u4e3a\u79c1\u6709\u51fd\u6570\u5417\uff1f<\/h3>\n\n\n\n

    \u57fa\u7c7b\u6307\u9488\u6307\u5411\u7ee7\u627f\u7c7b\u5bf9\u8c61\uff0c\u5219\u8c03\u7528\u7ee7\u627f\u7c7b\u5bf9\u8c61\u7684\u51fd\u6570\uff1b<\/p>\n\n\n\n

    int main()\u5fc5\u987b\u58f0\u660e\u4e3aBase\u7c7b\u7684\u53cb\u5143\uff0c\u5426\u5219\u7f16\u8bd1\u5931\u8d25\u3002 \u7f16\u8bd1\u5668\u62a5\u9519\uff1a ptr\u65e0\u6cd5\u8bbf\u95ee\u79c1\u6709\u51fd\u6570\u3002 \u5f53\u7136\uff0c\u628a\u57fa\u7c7b\u58f0\u660e\u4e3apublic\uff0c \u7ee7\u627f\u7c7b\u4e3aprivate\uff0c\u8be5\u95ee\u9898\u5c31\u4e0d\u5b58\u5728\u4e86\u3002<\/p>\n\n\n\n

    \u865a\u51fd\u6570\u53ef\u4ee5\u88ab\u5185\u8054\u5417\uff1f<\/strong><\/h3>\n\n\n\n

    \u901a\u5e38\u7c7b\u6210\u5458\u51fd\u6570\u90fd\u4f1a\u88ab\u7f16\u8bd1\u5668\u8003\u8651\u662f\u5426\u8fdb\u884c\u5185\u8054\u3002 \u4f46\u901a\u8fc7\u57fa\u7c7b\u6307\u9488\u6216\u8005\u5f15\u7528\u8c03\u7528\u7684\u865a\u51fd\u6570\u5fc5\u5b9a\u4e0d\u80fd\u88ab\u5185\u8054<\/strong>\u3002 \u5f53\u7136\uff0c\u5b9e\u4f53\u5bf9\u8c61\u8c03\u7528\u865a\u51fd\u6570\u6216\u8005\u9759\u6001\u8c03\u7528\u65f6\u53ef\u4ee5\u88ab\u5185\u8054\uff0c\u865a\u6790\u6784\u51fd\u6570\u7684\u9759\u6001\u8c03\u7528\u4e5f\u4e00\u5b9a\u4f1a\u88ab\u5185\u8054\u5c55\u5f00\u3002<\/p>\n\n\n\n

      \n
    • \u865a\u51fd\u6570\u53ef\u4ee5\u662f\u5185\u8054\u51fd\u6570\uff0c\u5185\u8054\u662f\u53ef\u4ee5\u4fee\u9970\u865a\u51fd\u6570\u7684\uff0c\u4f46\u662f\u5f53\u865a\u51fd\u6570\u8868\u73b0\u591a\u6001\u6027\u7684\u65f6\u5019\u4e0d\u80fd\u5185\u8054\u3002<\/strong><\/li>\n\n\n\n
    • \u5185\u8054\u662f\u5728\u7f16\u8bd1\u5668\u5efa\u8bae\u7f16\u8bd1\u5668\u5185\u8054\uff0c\u800c\u865a\u51fd\u6570\u7684\u591a\u6001\u6027\u5728\u8fd0\u884c\u671f\uff0c\u7f16\u8bd1\u5668\u65e0\u6cd5\u77e5\u9053\u8fd0\u884c\u671f\u8c03\u7528\u54ea\u4e2a\u4ee3\u7801\uff0c\u56e0\u6b64\u865a\u51fd\u6570\u8868\u73b0\u4e3a\u591a\u6001\u6027\u65f6\uff08\u8fd0\u884c\u671f\uff09\u4e0d\u53ef\u4ee5\u5185\u8054\u3002<\/li>\n\n\n\n
    • inlline virtual\u552f\u4e00\u53ef\u4ee5\u5185\u8054\u7684\u65f6\u5019\u662f\uff1a\u7f16\u8bd1\u5668\u77e5\u9053\u6240\u8c03\u7528\u7684\u5bf9\u8c61\u662f\u54ea\u4e2a\u7c7b\uff0c\u8fd9\u53ea\u6709\u5728\u7f16\u8bd1\u5668\u5177\u6709\u5b9e\u9645\u5bf9\u8c61\u800c\u4e0d\u662f\u5bf9\u8c61\u7684\u6307\u9488\u6216\u5f15\u7528\u65f6\u624d\u4f1a\u53d1\u751f\u3002<\/li>\n<\/ul>\n\n\n\n

      RTTI\u4e0edynamic_cast<\/h2>\n\n\n\n

      RTTI\uff08Run-Time Type Identification)\uff0c\u901a\u8fc7\u8fd0\u884c\u65f6\u7c7b\u578b\u4fe1\u606f\u7a0b\u5e8f\u80fd\u591f\u4f7f\u7528\u57fa\u7c7b\u7684\u6307\u9488\u6216\u5f15\u7528\u6765\u68c0\u67e5\u8fd9\u4e9b\u6307\u9488\u6216\u5f15\u7528\u6240\u6307\u7684\u5bf9\u8c61\u7684\u5b9e\u9645\u6d3e\u751f\u7c7b\u578b\u3002<\/p>\n\n\n\n

      \u5728\u9762\u5411\u5bf9\u8c61\u7a0b\u5e8f\u8bbe\u8ba1\u4e2d\uff0c\u6709\u65f6\u6211\u4eec\u9700\u8981\u5728\u8fd0\u884c\u65f6\u67e5\u8be2\u4e00\u4e2a\u5bf9\u8c61\u662f\u5426\u80fd\u4f5c\u4e3a\u67d0\u79cd\u591a\u6001\u7c7b\u578b\u4f7f\u7528\u3002\u4e0eJava\u7684instanceof\uff0c\u4ee5\u53caC#\u7684as\u3001is\u8fd0\u7b97\u7b26\u7c7b\u4f3c\uff0cC++\u63d0\u4f9b\u4e86dynamic_cast\u51fd\u6570\u7528\u4e8e\u52a8\u6001\u8f6c\u578b\u3002\u76f8\u6bd4C\u98ce\u683c\u7684\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362\u548cC++ reinterpret_cast\uff0cdynamic_cast\u63d0\u4f9b\u4e86\u7c7b\u578b\u5b89\u5168\u68c0\u67e5\uff0c\u662f\u4e00\u79cd\u57fa\u4e8e\u80fd\u529b\u67e5\u8be2(Capability Query)\u7684\u8f6c\u6362\uff0c\u6240\u4ee5\u5728\u591a\u6001\u7c7b\u578b\u95f4\u8fdb\u884c\u8f6c\u6362\u66f4\u63d0\u5021\u91c7\u7528dynamic_cast\u3002<\/p>\n\n\n\n

      \u7eaf\u865a\u51fd\u6570\u548c\u62bd\u8c61\u7c7b<\/h2>\n\n\n\n

      C++\u4e2d\u7684\u7eaf\u865a\u51fd\u6570(\u6216\u62bd\u8c61\u51fd\u6570)\u662f\u6211\u4eec\u6ca1\u6709\u5b9e\u73b0\u7684\u865a\u51fd\u6570\uff01\u6211\u4eec\u53ea\u9700\u58f0\u660e\u5b83! \u901a\u8fc7\u58f0\u660e\u4e2d\u8d4b\u503c0\u6765\u58f0\u660e\u7eaf\u865a\u51fd\u6570<\/p>\n\n\n\n

        \n
      • \u7eaf\u865a\u51fd\u6570\uff1a\u6ca1\u6709\u51fd\u6570\u4f53\u7684\u865a\u51fd\u6570<\/li>\n\n\n\n
      • \u62bd\u8c61\u7c7b\uff1a\u5305\u542b\u7eaf\u865a\u51fd\u6570\u7684\u7c7b<\/li>\n<\/ul>\n\n\n\n

        \u62bd\u8c61\u7c7b\u53ea\u80fd\u4f5c\u4e3a\u57fa\u7c7b\u6765\u6d3e\u751f\u65b0\u7c7b\u4f7f\u7528\uff0c\u4e0d\u80fd\u521b\u5efa\u62bd\u8c61\u7c7b\u7684\u5bf9\u8c61,\u62bd\u8c61\u7c7b\u7684\u6307\u9488\u548c\u5f15\u7528->\u7531\u62bd\u8c61\u7c7b\u6d3e\u751f\u51fa\u6765\u7684\u7c7b\u7684\u5bf9\u8c61<\/p>\n\n\n\n

        \u5b9e\u73b0\u62bd\u8c61\u7c7b<\/h3>\n\n\n\n

        \u62bd\u8c61\u7c7b\u4e2d\uff1a\u5728\u6210\u5458\u51fd\u6570\u5185\u53ef\u4ee5\u8c03\u7528\u7eaf\u865a\u51fd\u6570\uff0c\u5728\u6784\u9020\u51fd\u6570\/\u6790\u6784\u51fd\u6570\u5185\u90e8\u4e0d\u80fd\u4f7f\u7528\u7eaf\u865a\u51fd\u6570\u3002<\/p>\n\n\n\n

        \u5982\u679c\u4e00\u4e2a\u7c7b\u4ece\u62bd\u8c61\u7c7b\u6d3e\u751f\u800c\u6765\uff0c\u5b83\u5fc5\u987b\u5b9e\u73b0\u4e86\u57fa\u7c7b\u4e2d\u7684\u6240\u6709\u7eaf\u865a\u51fd\u6570\uff0c\u624d\u80fd\u6210\u4e3a\u975e\u62bd\u8c61\u7c7b\u3002<\/p>\n\n\n\n

        \u91cd\u8981\u70b9<\/h3>\n\n\n\n
          \n
        • \u7eaf\u865a\u51fd\u6570\u4f7f\u4e00\u4e2a\u7c7b\u53d8\u6210\u62bd\u8c61\u7c7b<\/li>\n<\/ul>\n\n\n\n
          \/\/ \u62bd\u8c61\u7c7b\u81f3\u5c11\u5305\u542b\u4e00\u4e2a\u7eaf\u865a\u51fd\u6570\nclass Base{\npublic:\n    virtual void show() = 0; \/\/ \u7eaf\u865a\u51fd\u6570\n    int getX() { return x; } \/\/ \u666e\u901a\u6210\u5458\u51fd\u6570\n\nprivate:\n     int x;\n}; <\/code><\/pre>\n\n\n\n
            \n
          • \u62bd\u8c61\u7c7b\u7c7b\u578b\u7684\u6307\u9488\u548c\u5f15\u7528<\/li>\n<\/ul>\n\n\n\n
            class Derived : public Base {\npublic:\n    void show() { cout << \"In Derived \\n\"; } \/\/ \u5b9e\u73b0\u62bd\u8c61\u7c7b\u7684\u7eaf\u865a\u51fd\u6570\n    Derived(){} \/\/ \u6784\u9020\u51fd\u6570\n};\n\nint main(void)\n{\n    \/\/Base b;  \/\/ error! \u4e0d\u80fd\u521b\u5efa\u62bd\u8c61\u7c7b\u7684\u5bf9\u8c61\n    \/\/Base *b = new Base(); error!\n\n    Base *bp = new Derived(); \/\/ \u62bd\u8c61\u7c7b\u7684\u6307\u9488\u548c\u5f15\u7528 -> \u7531\u62bd\u8c61\u7c7b\u6d3e\u751f\u51fa\u6765\u7684\u7c7b\u7684\u5bf9\u8c61\n    bp->show();\n    return 0;\n}<\/code><\/pre>\n\n\n\n
              \n
            • \u5982\u679c\u6211\u4eec\u4e0d\u5728\u6d3e\u751f\u7c7b\u4e2d\u8986\u76d6\u7eaf\u865a\u51fd\u6570\uff0c\u90a3\u4e48\u6d3e\u751f\u7c7b\u4e5f\u4f1a\u53d8\u6210\u62bd\u8c61\u7c7b<\/li>\n<\/ul>\n\n\n\n
              \/\/ Derived\u4e3a\u62bd\u8c61\u7c7b\nclass Derived: public Base\n{\npublic:\n\/\/    void show() {}\n}; <\/code><\/pre>\n\n\n\n
                \n
              • \u62bd\u8c61\u7c7b\u53ef\u4ee5\u6709\u6784\u9020\u51fd\u6570<\/li>\n<\/ul>\n\n\n\n
                \/\/ \u62bd\u8c61\u7c7b\nclass Base {\n    protected:\n        int x;\n    public:\n        virtual void fun() = 0;\n        Base(int i) { x = i; }  \/\/ \u6784\u9020\u51fd\u6570\n};\n\/\/ \u6d3e\u751f\u7c7b\nclass Derived: public Base\n{\n    int y;\npublic:\n    Derived(int i, int j) : Base(i) { y = j; } \/\/ \u6784\u9020\u51fd\u6570\n    void fun() { cout << \"x = \" << x << \", y = \" << y; }\n}; <\/code><\/pre>\n\n\n\n
                  \n
                • \u6784\u9020\u51fd\u6570\u4e0d\u80fd\u662f\u865a\u51fd\u6570\uff0c\u800c\u6790\u6784\u51fd\u6570\u53ef\u4ee5\u662f\u865a\u6790\u6784\u51fd\u6570<\/li>\n<\/ul>\n\n\n\n
                  \/\/ \u62bd\u8c61\u7c7b\nclass Base  {\npublic:\n    Base(){ cout << \"Constructor: Base\" << endl; }\n    virtual ~Base(){ cout << \"Destructor : Base\" << endl; }\n\n    virtual void func() = 0;\n};\n\nclass Derived: public Base {\npublic:\n    Derived(){ cout << \"Constructor: Derived\" << endl; }\n    ~Derived(){ cout << \"Destructor : Derived\" << endl;}\n\n    void func(){cout << \"In Derived.func().\" << endl;}\n};<\/code><\/pre>\n\n\n\n
                  \u5f53\u57fa\u7c7b\u6307\u9488\u6307\u5411\u6d3e\u751f\u7c7b\u5bf9\u8c61\u5e76\u5220\u9664\u5bf9\u8c61\u65f6\uff0c\u6211\u4eec\u53ef\u80fd\u5e0c\u671b\u8c03\u7528\u9002\u5f53\u7684\u6790\u6784\u51fd\u6570\u3002 \u5982\u679c\u6790\u6784\u51fd\u6570\u4e0d\u662f\u865a\u62df\u7684\uff0c\u5219\u53ea\u80fd\u8c03\u7528\u57fa\u7c7b\u6790\u6784\u51fd\u6570\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
                  \u624b\u673a\u4e0a\u6574\u7406\u7684\u4e0d\u591f\u8be6\u7ec6…\u5f53\u65f6\u88ab\u62f7\u6253\u7684\u5f88\u96be\u53d7\uff0c\u8fd8\u662f\u8981\u597d\u597d\u5b66\u4e0b\u5b66\u4e0b\u8fd9\u79cd\u57fa\u7840\u7684\u4e1c\u897f \u539f\u6587 \u57fa\u7840\u7406\u8bba vtable \u4e3a\u4e86\u5b9e\u73b0\u865a\u51fd\u6570\uff0cC  …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"emotion":"","emotion_color":"","title_style":"","license":"","footnotes":""},"categories":[22],"tags":[],"class_list":["post-1748","post","type-post","status-publish","format-standard","hentry","category-c"],"_links":{"self":[{"href":"https:\/\/courtship.top\/index.php\/wp-json\/wp\/v2\/posts\/1748","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courtship.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/courtship.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/courtship.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/courtship.top\/index.php\/wp-json\/wp\/v2\/comments?post=1748"}],"version-history":[{"count":3,"href":"https:\/\/courtship.top\/index.php\/wp-json\/wp\/v2\/posts\/1748\/revisions"}],"predecessor-version":[{"id":2440,"href":"https:\/\/courtship.top\/index.php\/wp-json\/wp\/v2\/posts\/1748\/revisions\/2440"}],"wp:attachment":[{"href":"https:\/\/courtship.top\/index.php\/wp-json\/wp\/v2\/media?parent=1748"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/courtship.top\/index.php\/wp-json\/wp\/v2\/categories?post=1748"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/courtship.top\/index.php\/wp-json\/wp\/v2\/tags?post=1748"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}