<cn>
#### 表单布局
表单有三种布局。
</cn>

<us>
#### Form Layout
There are three layout for form: `horizontal`, `vertical`, `inline`.
</us>


<template>
  <div>
    <a-form :layout="formLayout">
      <a-form-item
        label="Form Layout"
        :label-col="formItemLayout.labelCol"
        :wrapper-col="formItemLayout.wrapperCol"
      >
        <a-radio-group
          default-value="horizontal"
          @change="handleFormLayoutChange"
        >
          <a-radio-button value="horizontal">
            Horizontal
          </a-radio-button>
          <a-radio-button value="vertical">
            Vertical
          </a-radio-button>
          <a-radio-button value="inline">
            Inline
          </a-radio-button>
        </a-radio-group>
      </a-form-item>
      <a-form-item
        label="Field A"
        :label-col="formItemLayout.labelCol"
        :wrapper-col="formItemLayout.wrapperCol"
      >
        <a-input placeholder="input placeholder" />
      </a-form-item>
      <a-form-item
        label="Field B"
        :label-col="formItemLayout.labelCol"
        :wrapper-col="formItemLayout.wrapperCol"
      >
        <a-input placeholder="input placeholder" />
      </a-form-item>
      <a-form-item
        :wrapper-col="buttonItemLayout.wrapperCol"
      >
        <a-button type="primary">
          Submit
        </a-button>
      </a-form-item>
    </a-form>
  </div>
</template>

<script>
export default {
  data () {
    return {
      formLayout: 'horizontal',
    };
  },
  computed: {
    formItemLayout () {
      const { formLayout } = this;
      return formLayout === 'horizontal' ? {
        labelCol: { span: 4 },
        wrapperCol: { span: 14 },
      } : {};
    },
    buttonItemLayout () {
      const { formLayout } = this;
      return formLayout === 'horizontal' ? {
        wrapperCol: { span: 14, offset: 4 },
      } : {};
    },
  },
  methods: {
    handleFormLayoutChange  (e) {
      this.formLayout = e.target.value;
    },
  },
};
</script>




