问题描述

我正在使用 Vaadin 8.5.1 Grid 来显示 1000 行.一旦通过更改它的属性更新了一行，我使用grid.getDataProvider().refreshItem(selectedRow)或者grid.getDataProvider().refreshAll() 更新行失败.

我需要做显式的 grid.setItems() 来查看行的更新属性.

我正在使用下面的代码片段来创建一个网格

 msgGrid = new ABSMsgGrid();列出<ConsoleEntry>messageEntryList = new ArrayList<>();如果(输入控制台！= null){messageEntryList.addAll(inputConsole.getMessageEntryList());}msgGridDataProvider = new ListDataProvider(messageEntryList) {@覆盖公共对象 getId(ConsoleEntry 项) {返回 item.getId();}};msgGrid.setDataProvider(msgGridDataProvider);//在更改网格行的属性时，我使用下面的代码片段私人无效句柄HideRowMenuItem(GridContextMenu contextMenu，ConsoleEntry selectedConsoleItem){if (!selectedConsoleItem.isHidden()) {hideRowMenuItem = contextMenu.addItem("隐藏行", VaadinIcons.EYE_SLASH, selectedMenuItem -> {selectedConsoleItem.hide();**msgGridDataProvider.refreshItem(selectedConsoleItem);**}});}}公共类 ConsoleEntry {@覆盖公共布尔等于(对象 obj){//TODO 自动生成的方法存根if (obj instanceof ConsoleEntry) {ConsoleEntry temp = (ConsoleEntry) obj;字符串 msgRef2 = temp.getMsgRef();返回 this.getMsgRef().equalsIgnoreCase(msgRef2);}返回假；}@覆盖公共 int hashCode() {//TODO 自动生成的方法存根返回 super.hashCode();}公共字符串 getId(){返回 this.getMsgRef();}}

我见过类似的问题，但没有一个解决方案有效.

更改后如何刷新 vaadin Grid什么?

Vaadin - 行修改后刷新网格

如果有人可以分享如何解决这个问题的指针

TIA

要让一个项目被视为同一个项目，(并且刷新工作)你需要一个正确实现的 equals() 和对象上的 hashCode() 方法.

来自文档

public void refreshItem(T item)

从接口复制的描述:DataProvider

刷新给定的项目.这种方法应该用于通知所有DataProviderListeners 项目已被更新或替换为新实例.

要使其正常工作，该项目必须实现

equals( Object) 和 #hashCode() 认为旧项目实例和新项目实例相等，或者

DataProvider. getId( Object) 应该被实现以返回一个适当的标识符.

除此之外，您应该创建一个 ListDataProvider，将其分配给网格，然后通过先前分配的 ListDataProvider 的同一实例进行更新p>

I am using Vaadin 8.5.1 Grid to display 1000's of rows. Once a row is updated with change in it property, I use grid.getDataProvider().refreshItem(selectedRow) or grid.getDataProvider().refreshAll() which fails to update the row.

I need to do explicit grid.setItems() to see the updated property of the row.

I am using below snippet to create a Grid

    msgGrid = new ABSMsgGrid();

    List<ConsoleEntry> messageEntryList = new ArrayList<>();
    if (inputConsole != null) {
        messageEntryList.addAll(inputConsole.getMessageEntryList());
    }

    msgGridDataProvider = new ListDataProvider<ConsoleEntry>(messageEntryList) {

        @Override
        public Object getId(ConsoleEntry item) {
            return item.getId();
        }
    };

    msgGrid.setDataProvider(msgGridDataProvider);



//on changing property of the grid row, i use the below snippet
private void handleHideRowMenuItem(GridContextMenu<ConsoleEntry> contextMenu, ConsoleEntry selectedConsoleItem) {
        if (!selectedConsoleItem.isHidden()) {
            hideRowMenuItem = contextMenu.addItem("Hide Row", VaadinIcons.EYE_SLASH, selectedMenuItem -> {
                    selectedConsoleItem.hide();
                    **msgGridDataProvider.refreshItem(selectedConsoleItem);**
                }
            });
        }
}

public class ConsoleEntry {

        @Override
        public boolean equals(Object obj) {
            // TODO Auto-generated method stub
            if (obj instanceof ConsoleEntry) {
                ConsoleEntry temp = (ConsoleEntry) obj;
                String msgRef2 = temp.getMsgRef();
                return this.getMsgRef().equalsIgnoreCase(msgRef2);
            }
            return false;
        }

        @Override
        public int hashCode() {
            // TODO Auto-generated method stub
            return super.hashCode();
        }

        public String getId(){
            return this.getMsgRef();
        }
}       

I have seen similar question but none of the solutions worked.

How to refresh the vaadin Grid after you change something?

Vaadin - Refresh grid after row modification

Appreciate if any one could share pointers on how to solve this problem

TIA

For a item to be seen as the same item, (and the refresh working) you need a corretly implemented equals() and hashCode() methods on the object.

From the documentation

public void refreshItem(T item)

Description copied from interface: DataProvider

Refreshes the given item. This method should be used to inform all DataProviderListeners that an item has been updated or replaced with a new instance.

For this to work properly, the item must either implement

equals(Object) and #hashCode() to consider both the old and the new item instances to be equal, or alternatively

DataProvider.getId(Object) should be implemented to return an appropriate identifier.

In addition to this, it's you should create a ListDataProvider, assign it to the grid and then do the updated via the same instance of the previously assigned ListDataProvider

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