关于删除和应用 ADF 视图条件以编程方式查看对象的查询

Question

我有几个关于查看标准的问题

删除几个应用的视图条件后，我是否需要执行查询在应用相同或新的查看条件之前？
此外，在应用每个视图条件后，我是否需要执行查询？
如果我要应用的第一个查看条件是使用 testVO.applyViewCriteria(vc); 应用的，我是否需要先删除不需要的查看条件，或者是否会 applyViewCriteria(vc) 删除所有现有的查看条件？

我在下面的代码中试图做的是删除所有已应用的视图条件，然后应用我想要应用的新视图条件。

    testVO.getViewCriteriaManager().removeApplyViewCriteriaName("findByvc1");
    testVO.getViewCriteriaManager().removeApplyViewCriteriaName("findByvc2");
    testVO.getViewCriteriaManager().removeApplyViewCriteriaName("findByvc3");
    //testVO.executeQuery();
    
    ViewCriteria vc = testVO.getViewCriteriaManager().getViewCriteria("findByvc1");
    VariableValueManager vm = testVO.ensureVariableManager();
    vm.setVariableValue("vc1Var", 123);
    testVO.applyViewCriteria(vc);
    //testVO.executeQuery();
    ViewCriteria vc1 = testVO.getViewCriteriaManager().getViewCriteria("findByvc3");
    vm.setVariableValue("vc3Var", "test");
    testVO.applyViewCriteria(vc1, true);
    testVO.executeQuery();

Answer 1

这是一篇文章，其中我讨论了如何在 Oracle ADF 中以编程方式应用视图标准：https://cedricleruth.com/how-to-apply-a-viewcriteria-programmatically-in-adf/ 代码摘录：

/**
 * Apply view criteria named MyViewCriteria to it's ViewObject
 * by getting it through the binding iterator MyViewObjectIterator
 */
public void applyViewCriteriaOnViewObjectByIteratorName(String MyViewCriteriaName, String MyViewObjectIteratorName) {
    try {
        //Get The viewObject from the iterator define in the current binding context
        ViewObject vo = this.getViewObjectFromIteratorName(MyViewObjectIteratorName)
        //Get all it's ViewCriteria using the ViewCriteriaManager of the ViewObject
        ViewCriteriaManager vcm = vo.getViewCriteriaManager();
        //Get the specified View Criteria
        ViewCriteria vc = vcm.getViewCriteria(MyViewCriteriaName);
        //Apply the ViewCriteria to the ViewObject
        vo.applyViewCriteria(vc);
        //Note: If you need to apply this view criteria on top of already applied view criteria
        //without removing them you can add the following boolean parameter : 
        //vo.applyViewCriteria(vc,true);
        
        //That's all you need if the iterator is set to be refresh after this
        //If not you can force the ViewObject to execute by uncommenting the following :
        //vo.executeQuery(); 
    } catch (NullPointerException e) {
        //Log and warn for null
        //Often occur when there is an error in the provided attributes 
        //(MyViewCriteriaName, MyViewObjectIteratorName)
    } catch (Exception e) {
        //Log and warn for other exceptions - Should never be needed
}
    
/**
 * Useful function to get ViewObject from IteratorName
 * The iterator need to have a least one binding define in the current page
 * In this gist it's a private but i advice setting it as a public static in an utility class available for the whole Controller
 */
 private ViewObject getViewObjectFromIteratorName(String MyViewObjectIteratorName) {
    ViewObject vo = null;
    try {
        DCBindingContainer bindings = (DCBindingContainer) BindingContext.getCurrent().getCurrentBindingsEntry();
        DCIteratorBinding iterator = bindings.findIteratorBinding(MyViewObjectIteratorName);
        vo = iterator.getViewObject();      
    } catch (NullPointerException e) {
        //Log and warn for null
        //Often occur when there is an error in the provided attributes 
        //or if the iterator doesn't have a least one binding define in the current page
    }
    return vo;
 }

回答您的问题：

如果您的 vo 已经设置为刷新，则无需执行 executeQuery()。例如，如果您在迭代器上有一个 ppr。如果不是，你需要执行查询来强制刷新你的迭代器。
您不需要在每个 applyViewCriteria 之后执行查询，尤其是当您将第二个布尔参数设置为 true 时，它“在已应用的视图条件之上应用此视图条件”。它们将作为图层相互应用，并在您最后执行查询时设置。
如果您不将辅助布尔参数添加为 true，您的查看标准将是唯一应用的标准，所有其他标准将被自动删除。

关于删除和应用 ADF 视图条件以编程方式查看对象的查询

Query regarding removing and applying ADF view criteria's to view object programmatically

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