Question

我试图应用show / hide片段。这是我的代码：

public void loadSpinner() {
    final Fragment specialistPickerFragment = (Fragment) getFragmentManager().findFragmentById(R.id.fragmentAppoinmentDetail);
    kindOfAppoinmentSpinner = (Spinner) findViewById(R.id.kindOfAppoinment);
    List dataSrc = new ArrayList();
    dataSrc.add("Khám tổng quát");
    dataSrc.add("Khám chuyên khoa");
    ArrayAdapter adapter = new ArrayAdapter(MakingAppoinmentActivity.this, R.layout.spinner_config, dataSrc);
    adapter.setDropDownViewResource(R.layout.spinner_config);
    kindOfAppoinmentSpinner.setAdapter(adapter);

    kindOfAppoinmentSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            if (kindOfAppoinmentSpinner.getSelectedItem().toString().equals("Khám chuyên khoa")) {
                getFragmentManager().beginTransaction().setCustomAnimations(android.R.animator.fade_in, android.R.animator.fade_out)
                        .show(specialistPickerFragment).commit();

            } else {
                getFragmentManager().beginTransaction().setCustomAnimations(android.R.animator.fade_in, android.R.animator.fade_out)
                        .hide(specialistPickerFragment).commit();
            }
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });
}

我正在使用this question中的代码。但是当我前往我希望它生效的活动时，我的应用程序崩溃了。我在google上做了很多搜索，他们都有相同的代码。谁知道为什么？这是我的错误：

E / AndroidRuntime：致命异常：主要处理：com.example.hoang.bnhnint，PID：21150 java.lang.NullPointerException：尝试写入字段＆＃39; int android.app.Fragment.mNextAnim＆＃39;在null对象引用上在android.app.BackStackRecord.run（BackStackRecord.java:786）在android.app.FragmentManagerImpl.execPendingActions（FragmentManager.java:1582）在android.app.FragmentManagerImpl $ 1.run（FragmentManager.java:483）在android.os.Handler.handleCallback（Handler.java:751）在android.os.Handler.dispatchMessage（Handler.java:95）在android.os.Looper.loop（Looper.java:154）在android.app.ActivityThread.main（ActivityThread.java:6816） at java.lang.reflect.Method.invoke（Native Method）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:1565）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:1453）

应用显示/隐藏片段

0 个答案: