放大Cordova / Ionic中的特定div

Question

我添加了视口，其属性允许缩放/缩放。 我将这些添加到本机代码中：

WebSettings settings = super.appView.getSettings();
settings.setBuiltInZoomControls(true);
settings.setDisplayZoomControls(true);
settings.setSupportZoom(true);

我能够缩放，但随着我的观点， ion-header-bar和ion-nav-bar变焦。 我尝试给标头css，以保持固定：

position: fixed;
top: 0px;
left: 0px;

但它仍然会变焦。

我的index.html有一个ion-header-bar ，它包含一个图像。 模板进入

<ion-nav-view class="has-header"></ion-nav-view>

我需要放大特定div的模板有一个'离子视图'，它看起来像：

<ion-view>
    <ion-nav-bar class="bar-stable">
        <ion-nav-buttons side="right">
            icon1
        </ion-nav-buttons>
        <ion-nav-buttons side="left">
            icon2
        </ion-nav-buttons>
    </ion-nav-bar>
    <div>
        Multiple divs in here, which are containers for html and css data we receive via AJAX requests. And this is here I need zooming in.
    </div>
</ion-view>

PS：如果我在ion-view添加完整的HTML代码（带有meta视口，没有标题，但是正文和div），这是否重要？

Answer 1

我想获得类似的功能，并能够使用离子滚动使其工作。

<ion-scroll zooming="true" direction="xy" style="width: 100%; ">
  <div></div>
</ion-scroll>

Answer 2

另一个解决方案可能是使用hammerjs进行多点触控手势，并使用css来缩小和缩小内容以缩放内容。

像这样的东西：

var hammerTime = new Hammer.Manager($('div.youWantToScale')[0], {touchAction: "pan-x pan-y"});
var pinch = new Hammer.Pinch();
var lastZoom;
hammerTime.add(pinch);
hammerTime.on("pinchout pinchin", function(e) {
   var currentZoom = Number($('div.youWantToScale').css("zoom"));
   if (lastZoom) {
      var newZoom = currentZoom + (e.scale - lastZoom);

      //bounds checking for your zoom, min=1 and max=3 here
      newZoom = newZoom < 1 ? 1 : (newZoom > 3 ? 3 : newZoom); 
      $('div.youWantToScale').css("zoom", newZoom);
   } 
   lastZoom = e.scale;
});

hammerTime.on("pinchstart", function (e) {
   //Seems clunky, but reset the lastZoom on a new pinch   
   lastZoom = undefined;
});

Answer 3

感谢上面的@laughinpine，我在Ionic 4中提出了这个解决方案：

<ion-content scrollX scrollY>
  <div #map style="background-image: url('/assets/images/map.png');">
  </div>
</ion-content>


import * as Hammer from 'hammerjs';

@Component({
  ...
})
export class MapPage
  @ViewChild('map') public map: ElementRef;

  private readonly minZoom: number = 0.3;
  private readonly maxZoom: number = 2.0;
  private readonly zoomVelocity: number = 0.005;

  public constructor(private renderer: Renderer2) {}

  private addPinchToMap(): void {
    const hammerTime = new Hammer.Manager(this.map.nativeElement, { touchAction: 'pan-x pan-y' });
    const pinch = new Hammer.Pinch();
    let lastZoom: number = 1; // Default original zoom

    hammerTime.add(pinch);

    hammerTime.on('pinchin', (event: MSGestureEvent) => {
      let newZoom = lastZoom - this.zoomVelocity;
      newZoom = newZoom < this.minZoom ? this.minZoom : newZoom;
      this.renderer.setStyle(this.map.nativeElement, 'zoom', newZoom);
      lastZoom = newZoom;
    });

    hammerTime.on('pinchout', (event: MSGestureEvent) => {
      let newZoom = lastZoom + this.zoomVelocity;
      newZoom = newZoom > this.maxZoom ? this.maxZoom : newZoom;
      this.renderer.setStyle(this.map.nativeElement, 'zoom', newZoom);
      lastZoom = newZoom;
    });
  }
}