Question

我正在尝试编写一个测试，用于检查在更改设备方向时是否保留选择。问题是ListView在更改后没有孩子。有没有人对如何修复此测试有任何建议？

public void testSelectionAfterSaveInstanceState() throws Throwable {
    Log.d(TAG, "testSelectionAfterSaveInstanceState()");

    ListView lv = ((ListActivity) this.activity).getListView();
    ArrayList<Integer> indexes = new ArrayList<Integer>();

    for (int i = 0; i < 3; i++) {
        int cardIndex = (int) (Math.random() * (lv.getChildCount() - 1) + 1);
        final CheckedTextView ctv = (CheckedTextView) lv.getChildAt(
                cardIndex).findViewById(R.id.checkmark);

        if (!ctv.isChecked()) {
            indexes.add(cardIndex);

            this.runTestOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Assert.assertTrue(ctv.performClick());
                }
            });
        }
    }

    Log.d(TAG, "change orientation");
    this.activity
            .setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

    Log.d(TAG, "assertions");
    lv = ((ListActivity) this.activity).getListView();
    Log.d(TAG, "lv.getChildCount()=" + lv.getChildCount());             // 0
    for (int i = 0; i < indexes.size(); i++) {
        View row = lv.getChildAt(indexes.get(i));
        Log.d(TAG, "row=" + row);                                       // null
        CheckedTextView ctv = (CheckedTextView) row
                .findViewById(R.id.checkmark);                          // NPE
        Assert.assertTrue(ctv.isChecked());
    }

    Log.d(TAG, "finished");
}

由于受欢迎的需求，这里是精确的堆栈跟踪：

java.lang.NullPointerException
at bbct.android.common.activity.test.BaseballCardListWithDataTest.testSelectionAfterSaveInstanceState(BaseballCardListWithDataTest.java:513)
at java.lang.reflect.Method.invokeNative(Native Method)
at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:214)
at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:199)
at android.test.ActivityInstrumentationTestCase2.runTest(ActivityInstrumentationTestCase2.java:192)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:190)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:175)
at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:555)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1584)

此外，正在测试ListActivity的{{3}}。

在Android JUnit测试中更改方向时的NPE

0 个答案: