如何在React Native中切换抽屉式导航器？

Question

我正在使用抽屉式导航。 当我单击汉堡菜单图标时，抽屉导航的抽屉不起作用，我无法切换抽屉。 代码1无效，但是代码2有效，有人可以帮助我找出原因吗？

码：

    Burger menu icon code 1:

    // Inside Header
    navigationOptions: ({ navigation }) => ({
                // headerTitle: 'Rchampz',
                headerLeft:
                <TouchableOpacity  onPress={() => {navigation.dispatch(DrawerActions.toggleDrawer())} }>
                    <MenuImage navigation={navigation}/>
                </TouchableOpacity>,

//Created component and added inside navigationOptions

    const MenuImage = ({navigation}) => {
        if(!navigation.state.isDrawerOpen){
            return <TouchableOpacity><Image source={require('../assets/images/menu.png')} style={{width: 24, height: 24, resizeMode: 'contain' ,marginLeft: 15}}/></TouchableOpacity>
        }else{
            return <MenuIcon style={{paddingLeft: 10, paddingRight: 10}} name="md-arrow-back" size={30} color="black"/>
        }
    }

    Burger menu icon code 2:

    //Inside header

    navigationOptions: ({ navigation }) => ({
                // headerTitle: 'Rchampz',
                headerLeft:
                <TouchableOpacity  onPress={() => {navigation.dispatch(DrawerActions.toggleDrawer())} }>
                    <MenuImage navigation={navigation}/>
                </TouchableOpacity>,


//Created component and added inside navigationOptions

    const MenuImage = ({navigation}) => {
        if(!navigation.state.isDrawerOpen){
            return <MenuIcon style={{paddingLeft: 10, paddingRight: 10}} name="md-menu" size={30} color="black"/>
        }else{
            return <MenuIcon style={{paddingLeft: 10, paddingRight: 10}} name="md-arrow-back" size={30} color="black"/>
        }
    }

Answer 1

由于您在第一个菜单中设置菜单图像的方式。 您将Image包装在另一个TouchableOpacity ，这意味着内部的TouchableOpacity正在拾取用户触摸事件。 因为你要的这实际上不是你想要的行为TouchableOpacity上headerLeft是输入的接收器。 因此，只需删除“额外的” TouchableOpacity 。

// Inside Header
navigationOptions: ({ navigation }) => ({
    headerLeft:
    <TouchableOpacity onPress={() => {navigation.dispatch(DrawerActions.toggleDrawer())} }>
        <MenuImage navigation={navigation}/>
    </TouchableOpacity>,

//Created component and added inside navigationOptions
const MenuImage = ({navigation}) => {
    if(!navigation.state.isDrawerOpen){
        // No need of Touchable here. Since you want the above Touchable to pick up the onPress event.
        return <Image source={require('../assets/images/menu.png')} style={{width: 24, height: 24, resizeMode: 'contain' ,marginLeft: 15}}/>. 
    }else{
        return <MenuIcon style={{paddingLeft: 10, paddingRight: 10}} name="md-arrow-back" size={30} color="black"/>
    }
}

第二个示例起作用的原因很简单，没有额外的Touchable处理onPress事件。