javafx listview和treeview控件未正确重新绘制 [英] javafx listview and treeview controls are not repainted correctly

问题描述

我正在尝试使用javafx将元素放在listview和treeview上，但两个控件都不会刷新它们的内容。我使用一个obvservable列表来控制项目，每次我删除一个项目时，listview或treeview将其从数据源中删除。但视图没有更新。我还在看所有物品。唯一的区别是，删除的项目不能再被选中。例如，链接2显示了拼贴项目列表。图1显示了拼贴前的项目。项目已折叠，但旧条目仍然可见。有没有人知道这个问题的解决方案。谢谢大家帮助我

i am trying to put elements on a listview and treeview with javafx, but both controls wont refresh theyre content. i am using an obvservable list to control the items and every time i delete one item, the listview or treeview removes it from the datasource. but the view is not updating. i am still seeing all the items. the only difference is, the removed item can not be selected any more. for example link 2 shows the collaped item list. image 1 shows the items before they are collaped. the items are collapsed but the old entry is still visible. does anybody know a solution for this problem. thank you all for helping me

链接1： treeview未折叠
链接2：树视图已折叠但未更新旧视图

这是我用来显示列表视图的自定义单元工厂：

this is the custom cell factory i use to display a listview:

public ListCell<T> call(final ListView<T> param) {
        ListCell<T> cell = new ListCell<T>(){
            @Override
            protected void updateItem(final T persistentObject, final boolean empty) {
                super.updateItem(persistentObject, empty);
                if(persistentObject instanceof POProcessStep){
                    POProcessStep poProcessStep = (POProcessStep) persistentObject;
                    if (persistentObject != null) {
                        super.setText(poProcessStep.getId() + " - " + poProcessStep.getTitle());
                    }
                }else if(persistentObject instanceof POProcess){
                    POProcess poProcess = (POProcess) persistentObject; 
                    if (persistentObject != null) {
                        super.setText(poProcess.getId() + " - " + poProcess.getTitle());
                    }
                }else if(persistentObject instanceof POCategory){
                    POCategory poCategory = (POCategory) persistentObject;
                    if(persistentObject != null){
                        super.setText(poCategory.getId() + " - " + poCategory.getTitle());
                    }
                }else if(persistentObject instanceof String){
                    if(persistentObject != null){
                        super.setText(String.valueOf(persistentObject));
                    }
                }
                super.setGraphic(null);
            }
        };
        return cell;
    }

推荐答案

你的手机工厂的 updateItem（...）需要处理单元格为空的情况。这将是一个项目被删除（或因为 TreeView 中的节点被折叠而变空）并且之前显示项目的单元格被重用为空的情况cell：

Your cell factory's updateItem(...) needs to handle the case where the cell is empty. This will be exactly the scenario when an item is removed (or becomes empty because a node in the TreeView was collapsed) and the cell that previously showed an item is reused as an empty cell:

public ListCell<T> call(final ListView<T> param) {
    ListCell<T> cell = new ListCell<T>(){
        @Override
        protected void updateItem(final T persistentObject, final boolean empty) {
            super.updateItem(persistentObject, empty);
            if (empty) {
                setText(null);
                setGraphic(null);
            } else {
                // ... rest of your code.
            }
       }
    }
    return cell ;
}

这篇关于javafx listview和treeview控件未正确重新绘制的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！