ant-design/components/modal/demo/position.md

order	title
7	[{zh-CN 自定义位置} {en-US To customize the position of modal}]

zh-CN

使用 centered 或类似 style.top 的样式来设置对话框位置。

en-US

You can use centered,style.top or other styles to set position of modal dialog.

import { Modal, Button } from 'antd';

class App extends React.Component {
  state = {
    modal1Visible: false,
    modal2Visible: false,
  };

  setModal1Visible(modal1Visible) {
    this.setState({ modal1Visible });
  }

  setModal2Visible(modal2Visible) {
    this.setState({ modal2Visible });
  }

  render() {
    return (
      <>
        <Button type="primary" onClick={() => this.setModal1Visible(true)}>
          Display a modal dialog at 20px to Top
        </Button>
        <Modal
          title="20px to Top"
          style={{ top: 20 }}
          visible={this.state.modal1Visible}
          onOk={() => this.setModal1Visible(false)}
          onCancel={() => this.setModal1Visible(false)}
        >
          <p>some contents...</p>
          <p>some contents...</p>
          <p>some contents...</p>
        </Modal>
        <br />
        <br />
        <Button type="primary" onClick={() => this.setModal2Visible(true)}>
          Vertically centered modal dialog
        </Button>
        <Modal
          title="Vertically centered modal dialog"
          centered
          visible={this.state.modal2Visible}
          onOk={() => this.setModal2Visible(false)}
          onCancel={() => this.setModal2Visible(false)}
        >
          <p>some contents...</p>
          <p>some contents...</p>
          <p>some contents...</p>
        </Modal>
      </>
    );
  }
}

export default App;