为什么在扩展AndroidTestCase，一的getContext测试类（）函数返回null？ [英] Why in a test class that extends AndroidTestCase, getContext() function returns null?

问题描述

我有我自己的SQLiteOpenHelper如下：

I have a my own SQLiteOpenHelper as follow :

public class MyOpenHelper extends SQLiteOpenHelper {

  public static final int DB_VERSION = 1;
  public static final String DB_NAME = "dbname";

  public MyOpenHelper(Context context) {
    super(context, DB_NAME, null, DB_VERSION);
  }

  @Override
  public void onCreate(SQLiteDatabase sqLiteDatabase) {
    /* My create code */
  }

  @Override
  public void onUpgrade(SQLiteDatabase sqLiteDatabase, int oldVersion, int newVersion) {
    /* My upgrade code */
  }

  @Override
  public void onOpen(SQLiteDatabase db) {
    super.onOpen(db);
  }
}

和我AndroidTestCase测试类：

And my AndroidTestCase test class :

public class MyOpenHelperTest extends AndroidTestCase {

  protected MyOpenHelper myOpenHelper;
  protected SQLiteDatabase sqLiteDatabase;

  public MyBdOpenHelperTest() {
    super();

    assertNotNull( getContext() );

    this.myBdOpenHelper = new MyOpenHelper(getContext());
    this.sqLiteDatabase = this.myOpenHelper.getReadableDatabase();
}

后来，当我执行此测试类，我有这个错误堆栈跟踪：

Then when I execute this test class, i've got this error stack trace :

junit.framework.AssertionFailedError: Exception in constructor:  
testAndroidTestCaseSetupProperly (junit.framework.AssertionFailedError
at fr.power.db.MyOpenHelperTest.<init>(MyOpenHelperTest.java:21)
at java.lang.reflect.Constructor.constructNative(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:417)
at junit.runner.BaseTestRunner.getTest(BaseTestRunner.java:118)
...

为什么的getContext（）返回一个空上下文？因为我在非活动测试用例？

Why getContext() returns a null context ? Because i'm in a non Activity test case ?

我应该测试我SQLiteOpenHelper在ActivityUnitTestCase有关使用SQLiteOpenHelper活动？

Should i test my SQLiteOpenHelper in ActivityUnitTestCase about an activity that uses the SQLiteOpenHelper ?

有人可以提供一些帮助吗？我只是想测试我的SQLiteOpenHelper以确保数据库以及创建。

Someone can give some help please ? I just want to test my SQLiteOpenHelper to be sure database is well created.

推荐答案

有关访问背景，您可以：

1. 从 InstrumentationTestCase 扩展，然后调用 getInstrumentation（）的getContext（）


2. 使用反射来访问私有成员

1. Extend from InstrumentationTestCase and then call getInstrumentation().getContext()
2. Use reflection to access a private member

您可以看到code样品<一个href=\"http://stackoverflow.com/questions/8605611/get-context-of-test-project-in-android-junit-test-case\">this回答

You can see code samples at this answer

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