I set physics body to drawNode when touch ended but it does not fall down and it does not collide with the edge.

It’s my code:

#include “MainScene.h”
#include “SimpleAudioEngine.h”

USING_NS_CC;

Scene* MainScene::createScene()
{
    auto scene = Scene::createWithPhysics();
    scene->getPhysicsWorld()->setDebugDrawMask(PhysicsWorld::DEBUGDRAW_ALL);
    
    auto layer = MainScene::create();
    layer->setPhysicsWorld(scene->getPhysicsWorld());
    
    scene->addChild(layer);
    
    return scene;
}

bool MainScene::init()
{
    if ( !Layer::init() )
    {
        return false;
    }

    auto visibleSize = Director::getInstance()->getVisibleSize();
    Vec2 origin = Director::getInstance()->getVisibleOrigin();

    auto touchListener = EventListenerTouchOneByOne::create();
    touchListener->onTouchBegan = CC_CALLBACK_2(MainScene::myTouchBegan, this);
    touchListener->onTouchMoved = CC_CALLBACK_2(MainScene::myTouchMoved, this);
    
    this->_eventDispatcher->addEventListenerWithSceneGraphPriority(touchListener, this);
    
    drawNode = DrawNode::create();
    this->addChild(drawNode);
    
    auto edge = Node::create();
    edge->setPosition(Vec2(origin.x + visibleSize.width / 2, origin.y + visibleSize.height / 2));
    
    auto edgeBody = PhysicsBody::createEdgeBox(visibleSize, PHYSICSBODY_MATERIAL_DEFAULT, 3);
    edge->setPhysicsBody(edgeBody);
    
    this->addChild(edge);
    
    return true;
}

bool MainScene::myTouchBegan(cocos2d::Touch *touch, cocos2d::Event *event) {
    MainScene::lastTouchPos = drawNode->convertTouchToNodeSpace(touch);
    return true;
}

void MainScene::myTouchMoved(cocos2d::Touch *touch, cocos2d::Event *event) {
    Vec2 touchPos = drawNode->convertTouchToNodeSpace(touch);
    drawNode->drawSegment(lastTouchPos, touchPos, 4, Color4F::WHITE);
    lastTouchPos = touchPos;
}

void MainScene::myTouchEnded(cocos2d::Touch *touch, cocos2d::Event *event) {
    body = PhysicsBody::createBox(drawNode->getContentSize(), PhysicsMaterial(0, 0, 1));
    drawNode->setPhysicsBody(body);
}