用简单的方法来访问GObject对象的私有属性

这里只用到了最简单的方法，给我的感觉就是使用g_object_get/set函数来完成对已经安装的属性的存取工作。

目前我们还没有涉及到‘信号’这个NB的东西，连interface'接口'是什么，我也还没看到。

不过目前这点可怜的知识，能够对看懂gdk的源码产生一定的帮助了。

至少那些.h中的茫茫多的枚举和结构体的存在理由已经被我们找到了。

#include<glib-object.h>#define SOME_OBJECT_TYPE(some_object_get_type())#define SOME_OBJECT(obj)(G_TYPE_CHECK_INSTANCE_CAST((obj), SOME_OBJECT_TYPE, SomeObject))#define SOME_IS_OBJECT(obj)(GTYPE_CHECK_TYPE((obj), SOME_OBJECT_TYPE))#define SOME_OBJECT_CLASS(c)(G_TYPE_CHECK_CLASS_CAST((c), SOME_OBJECT_TYPE,SomeObjectClass))#define SOME_IS_OBJECT_CLASS(c)(G_TYPE_CHECK_CLASS_TYPE((c), SOME_OBJECT_TYPE))#define SOME_OBJECT_GET_CLASS(obj)(G_TYPE_INSTANCE_GET_CLASS((obj), SOME_OBJECT_TYPE, SomeObjectClass))#define SOME_OBJECT_GET_PRIVATE(obj)(G_TYPE_INSTANCE_GET_PRIVATE((obj), SOME_OBJECT_TYPE, SomeObjectPrivate))typedef struct _SomeObjectSomeObject;typedef struct _SomeObjectClassSomeObjectClass;typedef struct _SomeObjectPrivateSomeObjectPrivate;struct _SomeObject {GObject parent_obj;SomeObjectPrivate *priv;};struct _SomeObjectClass {GObjectClass parent_class;void (*born)(void);// 出生void (*grow)(SomeObject *self);// 成长};struct _SomeObjectPrivate {guint age;gchar *name;};enum {OBJECT_PROPERTY_0,OBJECT_PROPERTY_AGE,OBJECT_PROPERTY_NAME,OBJECT_PROPERTY_BORN,OBJECT_PROPERTY_GROW};void some_object_grow(SomeObject *self);void some_object_give_name(SomeObject *self, gchar *name);G_DEFINE_TYPE (SomeObject, some_object, G_TYPE_OBJECT)void some_object_set_property(GObject *object, guint property_id, const GValue *value, GParamSpec *pspec){SomeObject *self = SOME_OBJECT(object);switch(property_id) {case OBJECT_PROPERTY_AGE:self->priv->age = g_value_get_uint(value);g_print("%s age: %d.\n",__func__, self->priv->age);break;case OBJECT_PROPERTY_NAME:g_free(self->priv->name);self->priv->name = g_value_dup_string(value);g_print("%s name: %s.\n", __func__, self->priv->name);break;default:G_OBJECT_WARN_INVALID_PROPERTY_ID(object, property_id, pspec);break;}}void some_object_get_property(GObject *object, guint property_id, GValue *value, GParamSpec *pspec){SomeObject *self = SOME_OBJECT(object);switch (property_id) {case OBJECT_PROPERTY_AGE:g_value_set_uint(value, self->priv->age);break;case OBJECT_PROPERTY_NAME:g_value_set_string(value, self->priv->name);break;default:G_OBJECT_WARN_INVALID_PROPERTY_ID(object, property_id, pspec);break;}}static void born(void){g_print("a object was born.\n");}static void grow(SomeObject *self){guint age =0;g_object_get(G_OBJECT(self), "property-age", &age, NULL);age += 1;g_object_set(G_OBJECT(self), "property-age", age, NULL);}void some_object_dispose(GObject *gobject){SomeObject *slef = SOME_OBJECT(gobject);g_print("-- %s # %i\n",__func__, __LINE__);G_OBJECT_CLASS(some_object_parent_class)->dispose(gobject);}void some_object_finalize(GObject *gobject){SomeObject *self = SOME_OBJECT(gobject);g_free(self->priv->name);g_print("-- %s # %i\n",__func__, __LINE__);G_OBJECT_CLASS(some_object_parent_class)->finalize(gobject);}static void some_object_class_init(SomeObjectClass* g_class){g_type_class_add_private(g_class, sizeof(SomeObjectPrivate));GObjectClass *this_class = G_OBJECT_CLASS(g_class);GParamSpec *spec;g_print("-- %s # %i\n",__func__, __LINE__);this_class->dispose = &some_object_dispose;this_class->finalize = &some_object_finalize;this_class->set_property = &some_object_set_property;this_class->get_property = &some_object_get_property;spec = g_param_spec_uint("property-age",                "the age","Set/Get age",0,150,0,G_PARAM_READWRITE);g_object_class_install_property(this_class, OBJECT_PROPERTY_AGE, spec);spec = g_param_spec_string("property-name",                "the name","Set/Get name","no-name-set",G_PARAM_READWRITE);g_object_class_install_property(this_class, OBJECT_PROPERTY_NAME, spec);}void some_object_init(SomeObject *self){SomeObjectPrivate *priv;born();self->priv = priv = SOME_OBJECT_GET_PRIVATE(self);priv->age = 0;priv->name = g_strdup("no-name");g_print("-- %s # %i\n",__func__, __LINE__);g_object_set(G_OBJECT(self),"property-age",0,"property-name","no-name",NULL);}void some_object_grow(SomeObject *self){grow(self);guint age = 0;g_object_get(G_OBJECT(self),"property-age", &age, NULL);g_print("%s I'm %d years old.\n",__func__, age);}void some_object_give_name(SomeObject *self, gchar *name){g_object_set(G_OBJECT(self), "property-name", name, NULL);g_print("%s hi, my name is %s.\n",__func__, name);}int main(){g_print("****init the type system****\n");g_type_init();g_print("****init type system OK ****\n");SomeObject *testobj = g_object_new(SOME_OBJECT_TYPE, NULL);;some_object_give_name(testobj, "Tom");some_object_grow(testobj);some_object_grow(testobj);some_object_grow(testobj);g_object_unref(testobj);g_print("****finish GObject Demo ****\n");return 0;}

Makefile:

all:gcc `pkg-config --cflags --libs gobject-2.0` someobject.c -o test

输出结果：

****init the type system********init type system OK ****-- some_object_class_init # 117a object was born.-- some_object_init # 146some_object_set_property age: 0.some_object_set_property name: no-name.some_object_set_property name: Tom.some_object_give_name hi, my name is Tom.some_object_set_property age: 1.some_object_grow I'm 1 years old.some_object_set_property age: 2.some_object_grow I'm 2 years old.some_object_set_property age: 3.some_object_grow I'm 3 years old.-- some_object_dispose # 98-- some_object_finalize # 106****finish GObject Demo ****

虽然我们的技巧还很烂，不过能够交互了不是么，O(∩_∩)O哈哈哈~