feat(use): add useWindowSize

packages/vant-use/src/index.ts

@@ -1,4 +1,5 @@
 export { useToggle } from './useToggle';
 export { useClickAway } from './useClickAway';
+export { useWindowSize } from './useWindowSize';
 export { useScrollParent } from './useScrollParent';
 export { useEventListener } from './useEventListener';

packages/vant-use/src/useWindowSize/index.ts

@@ -0,0 +1,18 @@
+import { ref } from 'vue';
+import { inBrowser } from '../shared';
+import { useEventListener } from '../useEventListener';
+
+export function useWindowSize(initialWidth = 0, initialHeight = 0) {
+  const width = ref(inBrowser ? window.innerWidth : initialWidth);
+  const height = ref(inBrowser ? window.innerHeight : initialHeight);
+
+  const onResize = () => {
+    width.value = window.innerWidth;
+    height.value = window.innerHeight;
+  };
+
+  useEventListener('resize', onResize);
+  useEventListener('orientationchange', onResize);
+
+  return { width, height };
+}