string.wxs

/**
 * 参数1: 要截取的字符串
 * 参数2: 开始截取的index
 * 参数3: 结束截取的index
 */
var sub = function (val, start, end) {

  if (val == undefined || val == '' || val == null) {
    return;
  }
  var reg = getRegExp('\\\n','g');
  val = val.replace(reg,'');
  if (val.length > end) {
    return val.substring(start, end) + "...";
  } else {
    return val;
  }
}
module.exports.sub = sub;

　wxml文件引入：

<wxs src="../../wxs/string.wxs" module="tools" />

 

<navigator class="title" url="/pages/detail/detail?id={{item.id}}">{{tools.sub(item.title,0,22)}}</navigator>