angglar 4のダイナミックスタイルのbackground-mage

anguralr 4のbackground-mageの問題を参照してください.
Steyle binding
You can set inline style with a style binding.
Style binding syntax reembles propertybinding.Instead of an element property between braackets,start with the prefix  style、フォローアップby a dot(.)and the name of a CSS style property:  [style.style-property].src/ap/ap.com onent.

content_copy [style.color]="isSpecial ? 'red': 'green'">Red
 [style.background-color]="canSave ? 'cyan': 'grey'" >Save

Some style binding styles have a unit extension. The following example conditionally sets the font size in “em” and “%” units .

src/app/app.component.html

content_copy [style.font-size.em]="isSpecial ? 3 : 1" >Big
 [style.font-size.%]="!isSpecial ? 150 : 50" >Small

While this is a fine way to set a single style, the NgStyle directive is generally preferred when setting several inline styles at the same time.

， [style.styleAtribute] = "styleAtributeVar"

， background-image， image url base64 ， ？

， ts

this.bgpictrue= `url(data:image/jpeg;base64,${event.message.picture})`

”  sanitizing unsafe style value SafeValue must use [property]=binding: ， Ionic2 TypeScript url ， ： 
http://http://g.co/ng/security#xss

import { DomSanitizer } from '@angular/platform-browser';

this.bgpictrue = this.sanitizer.bypassSecurityTrustStyle(`url(data:image/jpeg;base64,${ event.message.picture})`);;

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