Android单元测试:如何清除SharedPreferences

Question

我试图清除我测试期间添加的所有SharedPreferences.我已经阅读了一些帖子和官方文档(SharedPreferences.Editor.clear()).但是当我运行单元测试后启动应用程序时,我仍然找到了测试值.

所以,在AndroidTestCase.tearDown()中,我这样做:

public class PrivateStorageUtilsTest extends AndroidTestCase {

private static final String KEY_SP_PACKAGE = "PrivateStorageUtilsTest";

    protected void setUp() throws Exception {
        super.setUp();

        // Clear everything in the SharedPreferences
        SharedPreferences sharedPreferences = getContext()
            .getSharedPreferences(KEY_SP_PACKAGE, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.clear();
        editor.commit();
    }

    protected void tearDown() throws Exception {
        // Clear everything in the SharedPreferences
        SharedPreferences sharedPreferences = getContext().
            getSharedPreferences(KEY_SP_PACKAGE, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.clear();
        editor.commit();
    }

}

我在SO上发现的所有其他问题都是关于commit()在clear()我已经完成的之后添加的问题.

编辑1添加setUp()方法

编辑2提供扩展课程

Answer 1

如果您使用的ActivityTestRule是Espresso,请尝试以下方法:

@Rule
public ActivityTestRule<MainActivity> activityTestRule =
    new ActivityTestRule<MainActivity>(MainActivity.class) {
        @Override
        protected void beforeActivityLaunched() {
            clearSharedPrefs(InstrumentationRegistry.getTargetContext());
            super.beforeActivityLaunched();
        }
    };

使用稍微修改过的版本的stevo.mit clearSharedPrefs:

private static final String KEY_SP_PACKAGE = "PrivateStorageUtilsTest";

/**
* Clears everything in the SharedPreferences
*/
private void clearSharedPrefs(Context context) {
    SharedPreferences prefs = 
        context.getSharedPreferences(KEY_SP_PACKAGE, Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = prefs.edit();
    editor.clear();
    editor.commit();
}

Answer 2

您应该扩展ActivityInstrumentationTestCase2并使用getInstrumentation().getTargetContext()以获取正在检测的目标应用程序的上下文(正在测试中)