如何在Angular2中做响应组件

Question

我正在进入Angular2.我的目标是创建一个响应式应用程序,加载不同的组件以响应不同的媒体查询设备宽度.我的工作示例有一个MatchMediaService:

import { Injectable } from '@angular/core';

@Injectable()
export class MatchMediaService 
{
    constructor()
    {

    }

    rules =
    {
        print: "print",
        screen: "screen",
        phone: '(max-width: 767px)',
        tablet: '(min-width: 768px) and (max-width: 1024px)',
        desktop: '(min-width: 1025px)',
        portrait: '(orientation: portrait)',
        landscape: '(orientation: landscape)',
        retina: '(-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi)'
    };

    Check = function (mq)
    {
        if (!mq)
        {
            return;
        }

        return window.matchMedia(mq).matches;
    };

/**********************************************
    METHODS FOR CHECKING TYPE   
 **********************************************/
    IsPhone()
    {
        return window.matchMedia(this.rules.phone).matches;
    };

    IsTablet = function ()
    {
        return window.matchMedia(this.rules.tablet).matches;
    };

    IsDesktop = function ()
    {
        return window.matchMedia(this.rules.desktop).matches;
    };

    IsPortrait = function ()
    {
        return window.matchMedia(this.rules.portrait).matches;
    };

    IsLandscape = function ()
    {
        return window.matchMedia(this.rules.landscape).matches;
    };

    IsRetina = function ()
    {
        return window.matchMedia(this.rules.retina).matches;
    };


/**********************************************
    EVENT LISTENERS BY TYPE
 **********************************************/    
    OnPhone(callBack)
    {
        if (typeof callBack === 'function')
        {
            var mql: MediaQueryList = window.matchMedia(this.rules.phone);

            mql.addListener((mql: MediaQueryList) =>
            {
                if (mql.matches)
                {
                    callBack(mql);
                }
            });
        }
    };

    OnTablet(callBack)
    {
        if (typeof callBack === 'function')
        {
            var mql: MediaQueryList = window.matchMedia(this.rules.tablet);

            mql.addListener((mql: MediaQueryList) =>
            {
                if (mql.matches)
                {
                    callBack(mql);
                }
            });
        }
    };

    OnDesktop(callBack)
    {
        if (typeof callBack === 'function')
        {
            var mql: MediaQueryList = window.matchMedia(this.rules.desktop);

            mql.addListener((mql: MediaQueryList) =>
            {
                if (mql.matches)
                {
                    callBack(mql);
                }
            });
        }
    };  

    OnPortrait(callBack)
    {
        if (typeof callBack === 'function')
        {
            var mql: MediaQueryList = window.matchMedia(this.rules.portrait);

            mql.addListener((mql: MediaQueryList) =>
            {
                if (mql.matches)
                {
                    callBack(mql);
                }
            });
        }
    };  

    OnLandscape(callBack)
    {
        if (typeof callBack === 'function')
        {
            var mql: MediaQueryList = window.matchMedia(this.rules.landscape);

            mql.addListener((mql: MediaQueryList) =>
            {
                if (mql.matches)
                {
                    callBack(mql);
                }
            });
        }
    };
}

然后在'父'组件(HomeComponent)中,我使用MatchMediaService来确定要加载哪个子组件(HomeMobileComponent或HomeDesktopComponent),具体取决于MatchMediaService返回的内容以及浏览器通过不同维度调整时触发的侦听器事件:

import { Component, OnInit, NgZone } from '@angular/core';
import { MatchMediaService } from '../shared/services/match-media.service';
import { HomeMobileComponent } from './home-mobile.component';
import { HomeDesktopComponent } from './home-desktop.component';

@Component({
    moduleId: module.id,
    selector: 'home.component',
    templateUrl: 'home.component.html',
    providers: [ MatchMediaService ],
    directives: [ HomeMobileComponent, HomeDesktopComponent ]
})
export class HomeComponent implements OnInit 
{
    IsMobile: Boolean = false;
    IsDesktop: Boolean = false;

    constructor(
        private matchMediaService: MatchMediaService,
        private zone: NgZone        
    )
    {
        //GET INITIAL VALUE BASED ON DEVICE WIDTHS AT TIME THE APP RENDERS
        this.IsMobile = (this.matchMediaService.IsPhone() || this.matchMediaService.IsTablet());
        this.IsDesktop = (this.matchMediaService.IsDesktop());

        var that = this;


        /*---------------------------------------------------
        TAP INTO LISTENERS FOR WHEN DEVICE WIDTH CHANGES
        ---------------------------------------------------*/

        this.matchMediaService.OnPhone(
            function (mediaQueryList: MediaQueryList)
            {
                that.ShowMobile();
            }
        );

        this.matchMediaService.OnTablet(
            function (mediaQueryList: MediaQueryList)
            {
                that.ShowMobile();
            }
        );

        this.matchMediaService.OnDesktop(
            function (mediaQueryList: MediaQueryList)
            {
                that.ShowDesktop();
            }
        );
    }

    ngOnInit()
    {

    }

    ShowMobile()
    {
        this.zone.run(() =>
        { // Change the property within the zone, CD will run after
            this.IsMobile = true;
            this.IsDesktop = false;
        });
    }

    ShowDesktop()
    {
        this.zone.run(() =>
        { // Change the property within the zone, CD will run after
            this.IsMobile = false;
            this.IsDesktop = true;
        });
    }   
}

<home-mobile *ngIf="(IsMobile)"></home-mobile>
<home-desktop *ngIf="(IsDesktop)"></home-desktop>

这种方法有效.我可以加载适当的组件来响应设备.它使我能够为设备定制组件(内容,样式,功能等),从而实现最佳用户体验.这也使我能够针对移动设备,平板电脑和桌面定位不同的组件(尽管我只关注移动设备和桌面设备).

有一个更好的方法吗？缺点是我强迫每个组件都由父组件组成,以通过MatchMediaService确定要加载哪个子组件.这可以扩展到在完整的生产级应用程序中工作吗？我对您对更好的方法的反馈非常感兴趣,或者如果这种方法对于完整的生产应用程序是可接受的和可扩展的.谢谢你的反馈.

Answer 1

您可以创建自定义媒体感知*ngIf或*ngSwitch结构指令以减少重复。

https://angular.io/docs/ts/latest/guide/structural-directives.html