@alifd/overlay/demo/baisc.md

overlay base component

---
title: Overlay
order: 0
---

Overlay 使用。

```jsx
import Overlay from '@alifd/overlay';

class Demo extends React.Component {
  constructor(props) {
    super(props);

    this.state = {
      visible: false,
      visible2: false,
      visible3: false,
    };
  }

  onClick = () => {
    this.setState({
      visible: !this.state.visible,
    });
  };

  onClose = () => {
    this.setState({
      visible: false,
    });
  };

  render() {
    return (
      <div>
        <button
          onClick={this.onClick}
          ref={(ref) => {
            this.btn = ref;
          }}
        >
          Toggle visible
        </button>
        <Overlay
          visible={this.state.visible}
          points={['tl', 'tr']}
          offset={[4, 0]}
          target={() => this.btn}
          safeNode={() => this.btn}
          onRequestClose={this.onClose}
          onOpen={() => console.log(/open/)}
          onClose={() => console.log(/close/)}
        >
          <div
            style={{
              width: 200,
              height: 200,
              background: '#999',
              borderRadius: 2,
              boxShadow: '0 3px 6px -4px #0000001f, 0 6px 16px #00000014, 0 9px 28px 8px #0000000d',
            }}
          />
        </Overlay>
        <button style={{ marginLeft: 8 }} onClick={() => this.setState({ visible2: true })}>
          Fixed FullScreen
        </button>
        <Overlay
          visible={this.state.visible2}
          onRequestClose={() => this.setState({ visible2: false })}
          disableScroll
          fixed
          offset={['calc(50vw - 90vw/2)', 'calc(50vh - 80vh/2)']}
        >
          <div
            style={{
              width: '90vw',
              height: '80vh',
              background: '#999',
              boxShadow: '0 3px 6px -4px #0000001f, 0 6px 16px #00000014, 0 9px 28px 8px #0000000d',
            }}
          >
            hello world
          </div>
        </Overlay>
      </div>
    );
  }
}

ReactDOM.render(<Demo />, mountNode);
```