信號槽是對象和對象之間的通信機(jī)制，類似于觀察者模式。

object.h

#ifndef DB_OBJECT #define DB_OBJECT #include <map># define db_slots # define db_signals protected # define db_emitclass Object; struct MetaObject{const char * sig_names;const char * slts_names;static void active(Object * sender, int idx); };struct Connection{Object * receiver;int method; };typedef std::multimap<int, Connection> ConnectionMap; typedef std::multimap<int, Connection>::iterator ConnectionMapIt;class Object{static MetaObject meta;void metacall(int idx); public:Object();virtual ~Object();static void db_connect(Object*, const char*, Object*, const char*);void testSignal(); db_signals:void sig1(); public db_slots:void slot1();friend class MetaObject; private:ConnectionMap connections; }; #endif #pragma once

object.cpp

#include <stdio.h> #include <string.h> #include "object.h"void MetaObject::active(Object* sender, int idx) {ConnectionMapIt it;std::pair<ConnectionMapIt, ConnectionMapIt> ret;ret = sender->connections.equal_range(idx);for (it = ret.first; it != ret.second; ++it) {Connection c = (*it).second;c.receiver->metacall(c.method);} }static const char sig_names[] = "sig1"; static const char slts_names[] = "slot1"; MetaObject Object::meta = { sig_names, slts_names };Object::Object() { }Object::~Object() { }static int find_string(const char * str, const char * substr) {if (strlen(str) < strlen(substr))return -1;int idx = 0;int len = strlen(substr);bool start = true;const char * pos = str;while (*pos) {if (start && !strncmp(pos, substr, len))// && pos[len] == '/n')return idx;start = false;if (*pos == '/n') {idx++;start = true;}pos++;}return -1; }void Object::db_connect(Object* sender, const char* sig, Object* receiver, const char* slt) {int sig_idx = find_string(sender->meta.sig_names, sig);int slt_idx = find_string(receiver->meta.slts_names, slt);if (sig_idx == -1 || slt_idx == -1) {perror("signal or slot not found!");}else {Connection c = { receiver, slt_idx };sender->connections.insert(std::pair<int, Connection>(sig_idx, c));} }void Object::sig1() {MetaObject::active(this, 0); }void Object::metacall(int idx) {switch (idx) {case 0:slot1();break;default:break;}; }void Object::slot1() {printf("hello dbzhang800!"); }void Object::testSignal() {db_emit sig1(); }

main.cpp

int main(){Object obj1, obj2;Object::db_connect(&obj1, "sig1", &obj2, "slot1");obj1.testSignal();... }

輸出結(jié)果為：“hello dbzhang800!”

總結(jié)

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