fix(applist): 修复滚动列表时容易触发拖拽问题

qml/AppUI/AppList.qml

@@ -61,14 +61,15 @@ AppListView {
                         height: appListView.itemHeight
                         anchors.centerIn: parent
                         acceptedButtons: Qt.LeftButton | Qt.RightButton
-                        drag.target: appItem
 
                         Drag.hotSpot.x: 48 / 2
                         Drag.hotSpot.y: 48 / 2
                         Drag.supportedActions: Qt.CopyAction
                         Drag.dragType: Drag.Automatic
-                        Drag.active: appItem.drag.active
                         Drag.mimeData: {"id": id, "favorite": favorite}
+                        Drag.onDragFinished: function (dropAction) {
+                            appItem.Drag.active = false;
+                        }
 
                         onClicked: {
                             if (mouse.button === Qt.RightButton) {
@@ -80,19 +81,28 @@ AppListView {
                                 return;
                             }
                         }
+
                         onPressed: {
                             normalUI.focus = false;
+                            // 在启动拖拽前进行截图，避免开始拖拽后没有图标
                             grabImage();
                         }
+
+                        onPressAndHold: {
+                            // 长按时启动拖拽
+                            Drag.active =  true;
+                        }
                     }
 
                     function grabImage() {
                         var icon = mouseGrabImage.createObject(appItem, {width: 48, height: 48, source: model.icon})
-                        icon.grabToImage(function(result) {
-                            appItem.Drag.imageSource = result.url
-                            return result;
-                        });
-                        icon.opacity = 0;
+                        if (icon !== null) {
+                            icon.grabToImage(function(result) {
+                                appItem.Drag.imageSource = result.url
+                                icon.destroy();
+                            });
+                            icon.visible = false;
+                        }
                     }
 
                     Component {