NSInvocation 回调使用

声明

NSInvocation* m_touchDown;

赋值

-(void) setTouchMoveCallback:(id) target sel:(SEL) sel {
    if (m_touchMove) {
        [m_touchMove release];
        m_touchMove = nil;
    }
    NSMethodSignature *sig= [target methodSignatureForSelector:sel];
    NSAssert(sig, @"");
    m_touchMove = [NSInvocation invocationWithMethodSignature:sig];
    [m_touchMove setTarget:target];
    [m_touchMove setSelector:sel];
    [m_touchMove setArgument:&self atIndex:2];
    [m_touchMove retain];
}

开始回调

- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
    if (m_touchDown) {
        [m_touchDown setArgument:&touch atIndex:3];
        [m_touchDown setArgument:&event atIndex:4];
        [m_touchDown invoke];
    }
    return YES;
}

使用

[btn setTouchDownCallback:self sel:@selector(eventTouchBegin:touch:event:)];

回调函数

-(void) eventTouchBegin:(myButton*) sender touch:(UITouch*) touch event:(UIEvent*) event {
   // TODO
}