java – 如何在JSF datatable中获取所选行索引？

我在index.xhtml上有一个数据库

<h:dataTable style="border: solid 2px black;"
    value="#{IndexBean.bookList}" var="item"
    binding="#{IndexBean.datatableBooks}">

    <h:column>
        <h:commandButton value="Edit" actionListener="#{IndexBean.editBook}">
            <f:param name="index" value="#{IndexBean.datatableBooks.rowIndex}"/>
        </h:commandButton>
    </h:column>
</h:dataTable>

我的豆

@ManagedBean(name="IndexBean")
@ViewScoped
public class IndexBean implements Serializable {
    private HtmlDataTable datatableBooks;

    public HtmlDataTable getDatatableBooks() {
        return datatableBooks;
    }

    public void setDatatableBooks(HtmlDataTable datatableBooks) {
        this.datatableBooks = datatableBooks;
    }

    public void editBook() throws IOException{
        int index = Integer.parseInt(FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get("index").toString());
        System.out.println(index);
    }
}

我的问题是,即使我点击不同的编辑按钮,我总是在服务器日志中获得相同的索引.假设有一个集合被提供给datatable.我没有在豆中显示.

如果我将范围从ViewScope更改为RequestScope,它可以正常工作. @ViewScoped有什么问题？提前致谢 ：)

编辑：

<h:column>
    <h:commandButton value="Edit" actionListener="#{IndexBean.editBook}" />
</h:column>

public void editBook(ActionEvent ev) throws IOException{
    if (ev.getSource() != null && ev.getSource() instanceof HtmlDataTable) {
        HtmlDataTable objHtmlDataTable = (HtmlDataTable) ev.getSource();
        System.out.println(objHtmlDataTable.getRowIndex());
    }
}

解决方法

您已经绑定了< h：dataTable>组件到bean.所有你需要做的是：

public void editBook() throws IOException{
    int index = datatableBooks.getRowIndex(); // Actually not interesting info.
    Book book = (Book) datatableBooks.getRowData(); // This is what you want.
}

< f：param>这里也不需要.更多提示也见this article.

更新：我可以重现你的问题.这可能是@ViewScoped的错误.当bean设置为@RequestScoped时,它的工作原理如预期.此外,当您删除组件绑定并从viewroot自己获取组件时,它的工作原理.我已经提交了issue 1658这个.