根据左侧字数，右边自动宽度

样式：

.search_box {

overflow: hidden;

width: 95%;

margin: 0 auto;

}

.no_space {

overflow: hidden;

text-overflow: ellipsis;

white-space: nowrap;

}

.search {

height: 58rpx;

line-height: 58rpx;

background: #f5f7f9;

border-radius: 29px;

min-width: 45%;

}

.search input {

font-size: 28rpx;

display: inline-block;

padding-left: 10rpx;

height: 58rpx;

color: #3d4250;

padding-right: 20rpx;

width: 100%;

}

html

<view class="search_box flex">

        <view class="city no_space" bindtap="href_city" data-type="1">

          <text>全国</text>

        </view>

        <view class="search flex flex-ac flex2">

          <icon type="search" size="12"></icon>

          <input type="text" class="" placeholder="搜索活动关键词" />

        </view>

      </view>