view的高度如果用百分比（如20%）， 外面加上<form>后布局就变了，如果高度用具体尺寸（如100px）而不用百分比，外面加上form就没事。不能用百分比吗？代码框架如下（两段代码的差异就只是红色部分，别的都一样）：
1、用百分比时,加入form后布局会被改变：
  <form bindsubmit="formSubmit">
  <view style="height:90%;display:flex;flex-direction:column;justify-content:center;background-color:#ffffff;">
    <view style="height:25%;display:flex;justify-content:center;align-items:center;background-color:#ff0000;">
       <text>Welcome</text>
    </view>
    <view style="height:25%;display:flex;justify-content:center;align-items:center;background-color:#ffff00;">
       <text>账号</text><input style="background-color:#c0c0c0;"></input>
    </view>
    <view style="height:25%;display:flex;justify-content:center;align-items:center;background-color:#008000;">
       <text>密码</text><input style="background-color:#c0c0c0;"></input>
    </view>  
    <view style="height:25%;display:flex;justify-content:center;align-items:center;background-color:#0000ff;">
       <button form-type="submit" size="default" type="primary" >Enter</button>
    </view>
  </view>
  </form>

2、用具体长度时,加入form后布局不会变：
  <form bindsubmit="formSubmit">
  <view style="height:400px;display:flex;flex-direction:column;justify-content:center;background-color:#ffffff;">
    <view style="height:25%;display:flex;justify-content:center;align-items:center;background-color:#ff0000;">
       <text>Welcome</text>
    </view>
    <view style="height:25%;display:flex;justify-content:center;align-items:center;background-color:#ffff00;">
       <text>账号</text><input style="background-color:#c0c0c0;"></input>
    </view>
    <view style="height:25%;display:flex;justify-content:center;align-items:center;background-color:#008000;">
       <text>密码</text><input style="background-color:#c0c0c0;"></input>
    </view>  
    <view style="height:25%;display:flex;justify-content:center;align-items:center;background-color:#0000ff;">
       <button form-type="submit" size="default" type="primary" >Enter</button>
    </view>
  </view>
  </form>

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