微信小程序 实现listview带字母滑动

 <!--字母滑动--> <view class="letter-position" wx:if="{{filterType == 'name'}}" hidden="{{letterShow?'true':''}}" style="z-index:{{Zindex}}" catchtouchstart="handlerAlphaTap" catchtouchmove="handlerMove" catchtouchend="handlerEnd">  <image class="no-stars star-icon" data-loc="star" src="../img/no-stars.png"></image>  <text class="letter" wx:for="{{groups}}" wx:for-item="group" data-loc="{{group.id}}" wx:key="L_{{group.id}}">   {{group.id}}  </text>  <text class="letter no-letter">   #  </text> </view>

<scroll-view scroll-into-view="{{locationTo}}" bindscrolltolower="onscrollLower" scroll-y="{{trues}}" style="height: {{clientHeihgt?clientHeihgt+'px':'auto'}}" bindscroll="scroll" scroll-top="{{scrollTop}}" hidden="{{favoriteCards.length==0 && starCards.length ==0}}">

handlerAlphaTap(e) {  var ap = e.target.dataset.loc; //字母  this.setData({   locationTo: ap  });  var list = this.data.groups;  this.offsetTop = (this.data.clientHeihgt - list.length * 16) / 2; }, handlerMove(e) {  var _this = this;  var list = this.data.groups;  var moveY = e.touches[0].clientY;  var rY = moveY - this.offsetTop;  if (rY >= 0) {   var index = Math.ceil((rY - 16) / 16);   if (0 <= index && index < list.length) {    _this.setData({     locationTo: list[index].id,     nonwApID: list[index].id,     fly: false,     //nonwAp: list[index]    });    // _this.setData({    //  nonwApID:_this.data.nonwAp.id    // });    }  } }, handlerEnd(e) {  //  try{  this.setData({   nonwApID: '',   fly: true,   // locationTo:this.data.nonwAp.id  });  // }catch(e){  // }  var _this = this;  this.setData({   scoTTTTp: e.currentTarget.dataset.scrollTop  }); },