void SwizzInstanceMethod(Class origClass, Class replaceClass, SEL origSel, SEL replaceSel)
{
Method origMethod = class_getInstanceMethod(origClass, origSel);
Method newMethod = class_getInstanceMethod(replaceClass, replaceSel);
if(class_addMethod(origClass, origSel, method_getImplementation(newMethod), method_getTypeEncoding(newMethod)))
class_replaceMethod(origClass, replaceSel, method_getImplementation(origMethod), method_getTypeEncoding(origMethod));
else
method_exchangeImplementations(origMethod, newMethod);
}
// -----------------------------------------------------------------------------
// Method Swizzling
void makeSelectorChain(Class cls, SEL headSelector, SEL addOnSelector){
Method aspectMethod = class_getInstanceMethod(cls, addOnSelector);
XAAssert(method_getImplementation(aspectMethod), "The aspect implementation should exist.");
Method originalMethod = class_getInstanceMethod(cls, headSelector);
XAAssert(method_getImplementation(originalMethod), "The original implementation should exist.");
// Exchange implementations
method_exchangeImplementations(originalMethod, aspectMethod);
return;
}
bool OBJC_EXCHANGE_NEWCLASS_METHOD_TEMPLATE(const char* orgClassStr,const char* orgSelector,
const char* newClassStr,const char* newSelector)
{
Class orgClass = objc_getClass(orgClassStr);
Class newClass = objc_getClass(newClassStr);
if(!orgClass || !newClass)
{
return false;
}
SEL orgMethod = sel_registerName(orgSelector);
SEL newMethod = sel_registerName(newSelector);
Method newMethodIns = class_getInstanceMethod(newClass, newMethod);
/*在旧的类添加类新方法后,那么只需要交换原有的方法即可*/
Method orgMethodIns = class_getInstanceMethod(orgClass, orgMethod);
/*防止方法不存在*/
if(!orgMethodIns || !newMethodIns)
{
return false;
}
IMP newMethodIMP = method_getImplementation(newMethodIns);
const char *newMethodStr = method_getTypeEncoding(newMethodIns);
class_addMethod(orgClass, newMethod, newMethodIMP, newMethodStr);
newMethodIns = class_getInstanceMethod(orgClass, newMethod);
method_exchangeImplementations(orgMethodIns, newMethodIns);
return true;
}
