WXTrackGame/miniprogram/pages/saomiao2/index.wxml

<xr-demo-viewer>
  <xr-ar-2dmarker
    disable-scroll
    id="main-frame"
    width="{{renderWidth}}"
    height="{{renderHeight}}"
    style="width:{{width}}px;height:{{height}}px;top:{{top}}px;left:{{left}}px;display:block;"
    markerImg=""
    bind:assetsstr="handlestr"
    bind:arTrackerState="handleARTrackerState"
    recordState="{{recordState}}"
    captureState="{{captureState}}"
  /> 
 <view wx:if="{{!loadedSaoMiao}}"  class="test" style="width: {{renderWidth}};height: {{renderHeight}}">
      <!-- 拍照按钮 -->
     <button  class="no-press-effect" style="width: 100%; height: 100%" >
        <image style="width: 120px; height: 80px;" src="{{ar_2image}}">
        </image>
          <view class="intro-title" ><text>请将摄像头对准五仙雕像左侧木桌上的祥云图案</text> 
          </view>
    </button>

  </view>

  <view wx:if="{{loadedSaoMiao}}" class="test" style=" width: {{renderWidth}};height: {{renderHeight}}">
    <button  class="no-press-effect" style="left: -30%;"bindtap="onClickBack"  >    
      <image style="width: 100px; height: 30px;" src="{{fanhui}}">
      </image>
    </button>
      <!-- 拍照按钮 -->
      <button  class="no-press-effect"  style="display:flex;" id='btn-photo-video' bindtouchstart="handleTouchStart" bindtouchend="handleTouchEnd" bindlongpress="handleLongPress" bindtap="handleClick">
        <image style="width: 140px; height: 110px;" src="{{paizhao}}">
        </image>
      </button>
  </view>
</xr-demo-viewer>