【发布时间】：2016-11-21 09:04:32
【问题描述】：
我正在涉足 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设备宽度的不同媒体查询。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在不同维度调整大小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以响应设备。它使我能够为设备自定义组件（内容、样式、功能等），从而实现最佳用户体验。这也让我能够针对移动设备、平板电脑和桌面设备定位不同的组件（尽管在示例中我只关注移动设备和桌面设备）。
有没有更好的方法来做到这一点？缺点是我强制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。这是否可以扩展以在完整的生产级应用程序中工作？我对您对更好方法的反馈非常感兴趣，或者这种方法对于完整的生产应用程序是否可以接受和可扩展。感谢您的反馈。
【问题讨论】：
标签： angular responsive-design angular2-routing angular2-directives