安装c/c++插件后，按ctrl+shift+p，

点击打开了c_cpp_properties.json文件，对其中的IncludePath进行编辑，示例如下：

"includePath": [
                "${workspaceFolder}/**",
                "${workspaceFolder}/include/**",
                "${workspaceFolder}/src/calc/include/dbus/**",
                "${workspaceFolder}/src/calc/include/util/**",
                "${workspaceFolder}/src/calc/include/main/**",
                "C:/mingw32/i686-w64-mingw32/include/c++",
                "C:/mingw32/i686-w64-mingw32/include/c++/i686-w64-mingw32",
                "C:/mingw32/i686-w64-mingw32/include/c++/backward",
                "C:/mingw32/i686-w64-mingw32/include",
                "C:/mingw32/include",
                "C:/mingw32/lib/gcc/i686-w64-mingw32/5.4.0/include",
                "C:/mingw32/lib/gcc/i686-w64-mingw32/5.4.0/include-fixed"
            ],

注意，如果a.h中还include了b.h，即使a.h在包含范围内，但b.h没在包含范围内的话，a.h上也仍然会显示波浪线。