我用彈性盒子寫四個< view>< /view>.
要求.第一個< view>預設顯示已點選狀態

解決方法就是給第一個view單獨加一個叫“active”的類名，加個樣式，其他三個不加就行了。
.active{
background-color: #eaeaea;
color:purple;
}

上一下程式碼：
< view class=’choose flex’>
< view class=”flex flex-center choose-item active” bindtap=’checked’ data-app=”first” style=’background-color:{{ first }}; color:{{ firstcolor }}’>
< view class=’choose-icon’>< image src=” style=’width:100%;height:100 image>< /view>
< view class=’choose-text’>001< /view>
< /view>

< view class=”flex flex-center choose-item” bindtap=’checked’ data-app=”second” style=’background-color:{{ second }}; color:{{ secondcolor }}’>
< view class=’choose-icon’>< image src=” style=’width:100%;height:100%;’>< /image>< /view>
< view class=’choose-text’>002< /view>
< /view>

< view class=”flex flex-center choose-item” bindtap=’checked’ data-app=”third” style=’background-color:{{ third }}; color:{{ thirdcolor }}’>
< view class=’choose-icon’>< image src=” style=’width:100%;height:100%;’>< /image>< /view>
< view class=’choose-text’>003< /view>
< /view>

< view class=”flex flex-center choose-item” bindtap=’checked’ data-app=”fourth” style=’background-color:{{ fourth }}; color:{{ fourthcolor }}’>
< view class=’choose-icon’>< image src=” style=’width:100%;height:100%;’>< /image>< /view>
< view class=’choose-text’>004< /view>
< /view>
< /view>

給每個view繫結一個bindtap事件，再自定義一個data-app屬性，然後再樣式上進行資料繫結，在JS裡用setData來改變樣式。微信裡沒有DOM操作。。。
JS程式碼：
data: {
first:”,
firstcolor:”,
second:”,
secondcolor:”,
third:”,
thirdcolor:”,
fourth:”,
fourthcolor:”
},
checked:function(e) {
// 獲取到HTML頁面上定義的data-app的值
var app=e.currentTarget.dataset.app;
if(app==”first”){
this.setData({
first:’#eaeaea’,
firstcolor:’purple’,
second:’#fafafa’,
secondcolor:’#000’,
third:’#fafafa’,
thirdcolor:’#000’,
fourth:’#fafafa’,
fourthcolor:’#000’
})
};
if(app==”second”){
this.setData({
first: ‘#fafafa’,
firstcolor:’#000’,
second: ‘#eaeaea’,
secondcolor: ‘purple’,
third: ‘#fafafa’,
thirdcolor: ‘#000’,
fourth: ‘#fafafa’,
fourthcolor: ‘#000’
})
};
if(app==’third’){
this.setData({
first: ‘#fafafa’,
firstcolor: ‘#000’,
second: ‘#fafafa’,
secondcolor: ‘#000’,
third: ‘#eaeaea’,
thirdcolor: ‘purple’,
fourth: ‘#fafafa’,
fourthcolor: ‘#000’
})
};
if(app==’fourth’){
this.setData({
first: ‘#fafafa’,
firstcolor: ‘#000’,
second: ‘#fafafa’,
secondcolor: ‘#000’,
third: ‘#fafafa’,
thirdcolor: ‘#000’,
fourth: ‘#eaeaea’,
fourthcolor: ‘purple’
})
}
}