正常:在select中加maxSelected参数即可
在Form中:通过截取value去控制option的选中个数
<Form {...formItemLayout} onSubmit={this.handleSubmit}>
<Form.Item label="E-mail">
{getFieldDecorator("email", {
initialValue: ["1", "2"],
getValueFromEvent: value => value.slice(0, 3)
})(
<Select
mode="multiple"
style={{ width: "100%" }}
placeholder="Please select"
>
<Option value="1">1</Option>
<Option value="2">2</Option>
<Option value="3">3</Option>
<Option value="4">4</Option>
<Option value="5">5</Option>
</Select>
)}
</Form.Item>
</Form>