问题描述
我正在开发e4应用程序。我想在注入EPartService时将EPartService注入Part和处理程序
之外，然后会出现空指针错误
I am developing e4 application. I want to inject EPartService outside the Part and Handlerwhen i am injecting EPartService then i will get null pointer error
public class DisplayRuntimePart {
@Inject EPartService partService;
private void displayPart(){
MPart part=partService.findPart("com.rcpe4.myproject.part.datapart");
mpart.setVisible(true);
partService.showPart(mpart, PartState.CREATE);
}
}
我也读过这个问题，但是直到解决不了我问题
I am also read this question but till not solve my problem E4 EPartService findPart() throwing java.lang.Null Pointer Exception
编辑
我在零件类中注入了EPartService。 Application.e4xml中的类URI是此类中的bundleclass：//：//com.abc.test/com.abc.test.part.MyPart。
EditI am inject EPartService in Part class. Class URI in Application.e4xml is bundleclass://com.abc.test/com.abc.test.part.MyPart in this class I am write code as follows.
Class Mypart{
@Inject EPartService prtservice;
@Inject
public MyPart() {
}
@PostConstruct
public void postConstruct(Composite parent) {
parent.setLayout(new FillLayout(SWT.HORIZONTAL));
htmlBrowser = new Browser(parent, SWT.NONE);
}
@PreDestroy
public void preDestroy() {
}
@Focus
public void onFocus() {
}
@Persist
public void save() {
}
public dispalyPart(){
MPart mpart=partService.findPart("com.abc.test.part.datapart"); **Here Getting Null Pointer Exception**
mpart.setVisible(true);
partService.showPart(mpart, PartState.CREATE);
}
}
推荐答案
Eclipse仅对它知道的对象进行直接注入-基本上是应用程序模型（e4xmi）文件中提及的对象或使用 EPartService.showPart 之类的对象创建的对象。
Eclipse only does direct injection on objects that it 'knows' about - basically objects mentioned in the application model (e4xmi) files or created using something like EPartService.showPart.
如果要对创建的对象进行直接注入，则需要使用 ContextInjectionFactory 创建它们。例如：
If you want to do direct injection on objects that you create then you need to create them using ContextInjectionFactory. For example:
@Inject IEclipseContext context;
...
MyClass myClass = ContextInjectionFactory.make(MyClass.class, context);
您还可以使用以下常规方法对通过类创建的类进行注入：
you can also do injection on a class created in the normal way with:
ContextInjectionFactory.inject(myClass, context);
（这不会对构造函数进行注入）。
(this will not do injection on the constructor).
注意：由于此代码使用直接注入，因此必须从Eclipse应用程序模型确实了解的类（例如命令处理程序或MPart）中运行它。
Note: Since this code is using direct injection you must run it from a class that the Eclipse application model does know about such as a command handler or an MPart.
这篇关于如何注入EPartService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！