直接上代码

实现功能为：当fbphotoFirst为空时，src路径为“pic/信息反馈1-1_14.png“，并且点击事件uploadfbphotoFirst有效，否则为路径fbphotoFirst，此时点击事件uploadfbphotoFirst无效，uploadfbphotoFirst为上传图片的方法，即上传图片成功后不支持修改

<image class="uploadimageclass"
  bindtap="{{fbphotoFirst==‘‘?‘uploadfbphotoFirst‘:‘‘}}" mode="aspectFit" src="http://www.mamicode.com/{{fbphotoFirst==‘‘?‘pic/信息反馈1-1_14.png‘:fbphotoFirst}}"></image>
  <image class="uploadimageclass"
  bindtap="uploadfbphotoSecend" mode="aspectFit" src="http://www.mamicode.com/{{fbphotoFirst==‘‘?‘pic/信息反馈1-1_14.png‘:fbphotoSecend}}"></image>
  <image class="uploadimageclass"
  bindtap="uploadfbphotothird" mode="aspectFit" src="http://www.mamicode.com/{{fbphotoFirst==‘‘?‘pic/信息反馈1-1_14.png‘:fbphotothird}}"></image>
 

等效于以下代码
 <!--<view wx:if="{{fbphotoFirst==‘‘}}">
 <image class="uploadimageclass" bindTap="uploadfbphotoFirst" src="http://www.mamicode.com/image/信息反馈/信息反馈1-1_14.png"></image></view>
 <view wx:else> <image class="uploadimageclass" bindTap="uploadfbphotoFirst" src="http://www.mamicode.com/{{fbphotoFirst}}"></image></view>

 <view wx:if="{{fbphotoFirst==‘‘}}">
 <image class="uploadimageclass" bindTap="uploadfbphotoSecend" src="http://www.mamicode.com/image/信息反馈/信息反馈1-1_14.png"></image></view>
 <view wx:else> <image class="uploadimageclass" bindTap="uploadfbphotoSecend" src="http://www.mamicode.com/{{fbphotoSecend}}"></image></view>

 <view wx:if="{{fbphotoFirst==‘‘}}">
 <image class="uploadimageclass" bindTap="uploadfbphotothird" src="http://www.mamicode.com/image/信息反馈/信息反馈1-1_14.png"></image></view>
  <view wx:else> <image class="uploadimageclass" bindTap="uploadfbphotothird" src="http://www.mamicode.com/{{fbphotothird}}"></image></view>-->

微信小程序开发之三元运算符代替wx.if/wx.else