拖拽返回首页按钮时，屏幕不动，且在可视范围内

h5/pages/components/goHome.vue

@@ -30,9 +30,19 @@ const dragButton = (event) => {
 
   // 添加鼠标移动监听
   mouseMoveTracker = (event) => {
+    document.body.style.overflow = "hidden";
     posX = event.touches[0]?.clientX - startX;
     posY = event.touches[0]?.clientY - startY;
-    button.value.style.position = "absolute";
+    if (posX < 0) {
+      posX = 0;
+    } else if (posX > document.body.clientWidth - button.value.clientWidth) {
+      posX = document.body.clientWidth - button.value.clientWidth;
+    }
+    if (posY < 0) {
+      posY = 0;
+    } else if (posY > document.body.clientHeight - button.value.clientHeight) {
+      posY = document.body.clientHeight - button.value.clientHeight;
+    }
     button.value.style.top = `${posY}px`;
     button.value.style.left = `${posX}px`;
   };
@@ -40,6 +50,7 @@ const dragButton = (event) => {
 
   // 添加鼠标释放监听
   mouseUpTracker = () => {
+    document.body.style.overflow = "auto";
     document.removeEventListener("touchmove", mouseMoveTracker);
     document.removeEventListener("touchend", mouseUpTracker);
   };
@@ -48,13 +59,21 @@ const dragButton = (event) => {
 
 onMounted(() => {
   if (!button.value) {
-    document.body.appendChild(button.value);
+    var child = document.getElementById("draggable-button");
+    if (!document.body.contains(child)) {
+      document.body.appendChild(button.value);
+    }
   }
 });
 
 onBeforeUnmount(() => {
   if (button.value) {
-    document.body.removeChild(button.value);
+    var child = document.getElementById("draggable-button");
+    if (document.body.contains(child)) {
+      document.body.removeChild(child);
+    } else {
+      console.log("节点不是父节点的子节点");
+    }
   }
 });
 </script>