我使用此項目https://github.com/googlesamples/android-RecyclerView作爲參考,以瞭解RecyclerView,並通過MLProgrammer-Cim here來實現答案以處理onClick事件。使用RecyclerView進行Android語音識別
在我CustomAdapter
活動我試圖啓動一個方法speakNow();
這是另一個活動MainActivity
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.ViewHolder> {
private static final String TAG = "CustomAdapter";
...
public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
...
public MyViewHolderClicks mListener;
private Context context;
MainActivity ma = new MainActivity();
// FragmentTransaction ft = ((FragmentActivity)context).getSupportFragmentManager().beginTransaction();
// SampleActivityBase fragment = (SampleActivityBase)ft.findFragmentByTag("SampleActivityBase");
public ViewHolder(View myv, MyViewHolderClicks listener) {
super(myv);
mListener = listener;
....
imageIcon.setOnClickListener(this);
myv.setOnClickListener(this);
this.context =context;
}
@Override
public void onClick(View v) {
int position = getLayoutPosition();
if (v instanceof Button){
mListener.onTomato((Button) v, getLayoutPosition());
switch (v.getId()) {
case R.id.button_for_cardview:
ma.speakNow();
.....
}
}
我MainActivity
public class MainActivity extends SampleActivityBase {
....
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
....
//Intent intent = new Intent(getApplicationContext(), CustomAdapter.class);
//startActivityForResult(new Intent(this, CustomAdapter.class), checka);
if (savedInstanceState == null) {
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
RecyclerViewFragment fragment = new RecyclerViewFragment();
transaction.replace(R.id.sample_content_fragment, fragment);
transaction.commit();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == checka && resultCode == RESULT_OK){
ArrayList<String> results = data.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);
lv.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, results));
.....
}
}
super.onActivityResult(requestCode, resultCode, data);
}
protected void speakNow() {
Intent a = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
a.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
a.putExtra(RecognizerIntent.EXTRA_MAX_RESULTS, 6);
a.putExtra(RecognizerIntent.EXTRA_PROMPT, GlobalVariables.getInstance().getRightAnswer1());
startActivityForResult(a, checka);
}
....
}
這返回一個NullPointerException在 MainActivity.speakNow(MainActivity.java:478)
這是startActivityForResult(a, checka);
和適配器$ ViewHolder.onClick(CustomAdapter.java:287),這是ma.speakNow();
我讀過的各種「呼籲其他活動方法返回的NPE」,提問和回答,也不太清楚如何將這些應用到我的情況下,因爲MainActivity擴展了SampleActivityBase
這是一個擴展FragmentActivity的公共抽象類。
我在哪裏/如何初始化MainActivity ma = new MainActivity();所以它不是零?由於
感謝您的回覆。我確定這是一個非常完整的答案,但由於我的限制,我不明白如何將活動的參考傳遞給適配器,以及如何將它設置爲觸發speakNow()方法..您可以詳細說明使用我發佈的代碼上面..謝謝 – Mcorv
好吧,找出你的意思..再次感謝! – Mcorv