我是Android的新手，我试图显示一个评论列表，其中包含更多＆＃34;加载更多＆＃34;按钮。但不知怎的，我的按钮没有触发。听众似乎没有做任何事情...... 这是我的代码：
public class CommentActivity extends AppCompatActivity {
ListView listComments;
private String FullJson = "";
private static int current_page = 0;
private int offset = 0;
public int getOffset() {
return current_page * 10;
}
private ProgressDialog pDialog = null;
protected String qid = "", udida="";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_comment);
listComments = (ListView) findViewById(R.id.listComments);
//get list of comments on this question
Intent intent = getIntent();
qid = intent.getStringExtra(QuestionActivity.EXTRA_QID);
udida = intent.getStringExtra(QuestionActivity.EXTRA_MESSAGE);
FullJson = intent.getStringExtra(QuestionActivity.EXTRA_JSON);
new HttpAsyncTask().execute("http://heycrowd.com/requests/questionWithComments.json?questionId="+qid+"&offset="+getOffset());
// LoadMore button
Button btnLoadMore = (Button) findViewById(R.id.load_more);;
//Listening to Load More button click event
btnLoadMore.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// Starting a new async task
new GetIdTask().execute();
}
});
}
public String getIdThread () {
try {
Context ctx = CommentActivity.this.getApplicationContext();
AdvertisingIdClient.Info adInfo = AdvertisingIdClient.getAdvertisingIdInfo(ctx);
final String id = adInfo.getId();
return id;
} catch (GooglePlayServicesRepairableException e) {
return "Error 1";
} catch (IOException e) {
return "Error 2";
// Unrecoverable error connecting to Google Play services (e.g.,
// the old version of the service doesn't support getting AdvertisingId).
} catch (GooglePlayServicesNotAvailableException e) {
return"Error 3";
// Google Play services is not available entirely.
}
}
private class GetIdTask extends AsyncTask<String, Void, String> {
@Override
protected void onPreExecute() {
// Showing progress dialog before sending http request
pDialog = new ProgressDialog(CommentActivity.this);
pDialog.setMessage("Please wait..");
pDialog.setIndeterminate(true);
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected String doInBackground(String... urls) {
return getIdThread();
}
// onPostExecute displays the results of the AsyncTask.
@Override
protected void onPostExecute(String result) {
new HttpAsyncTask().execute("http://heycrowd.com/requests/questionWithComments.json?questionId="+qid+"&offset="+getOffset());
// closing progress dialog
pDialog.dismiss();
}
}
private List<HashMap<String,String>> getListItems(JSONArray FullJson) {
// Each row in the list stores country name, currency and flag
List<HashMap<String,String>> aList = new ArrayList<HashMap<String,String>>();
for(int i=0; i< FullJson.length() ;i++){
HashMap<String, String> hm = new HashMap<String,String>();
try {
hm.put("text", FullJson.getJSONObject(i).getString("text"));
hm.put("date", FullJson.getJSONObject(i).getString("created_at"));
//get user (picture + name)
JSONObject userObj = FullJson.getJSONObject(i).getJSONObject("user");
hm.put("user_id", userObj.getString("user_id"));
hm.put("user_name", userObj.getString("name"));
hm.put("user_img",userObj.getString("image_url"));
}
catch (JSONException e) {
//some exception handler code.
}
aList.add(hm);
}
return aList;
}
private void populateListView(JSONArray FullJson) {
setContentView(R.layout.activity_comment);
List<HashMap<String,String>> aList = getListItems(FullJson);
ListView listCommentView = (ListView) findViewById(R.id.listComments);
int currentPosition = listCommentView.getFirstVisiblePosition();
CommentAdapter adapter =new CommentAdapter(this, aList );
// Setting the adapter to the listView
listCommentView.setAdapter(adapter);
// Setting new scroll position
listCommentView.setSelectionFromTop(currentPosition + 1, 0);
//get logged user's image (at the moment, default image)
ImageLoader imageLoader = new ImageLoader(this.getApplicationContext());
ImageView image=(ImageView)findViewById(R.id.me_img);
image.setImageResource(R.drawable.ic_launcher);
}
private class HttpAsyncTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
return Utils.GET(urls[0]);
}
// onPostExecute displays the results of the AsyncTask.
@Override
protected void onPostExecute(final String result) {
try {
JSONObject json = new JSONObject(result);
JSONArray commentsArr = json.getJSONObject("question").getJSONArray("comments"); // get comments array
populateListView(commentsArr);
} catch (JSONException e) {
//some exception handler code.
}
}
}
}
因此，当我第一次在我的页面上获得时，我得到了前10个评论，但是当我点击我的＆＃34;加载更多＆＃34;按钮：没有任何反应。 我已经在getIdTask（）上设置了一个分数，因为应该在click事件上调用，我永远不会到达那里。我似乎无法找到为什么我的按钮没有任何反应。 另外，我想可能会多次调用AsyncTask可能是问题，但我尝试了＃34; OnCreate＆＃34;获得没有Asynctask的前10行，然后再没有任何工作...... 我从昨天起就坚持这个，请帮助！
我还添加了布局XML以防万一：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="20dp"
android:orientation="vertical"
>
<Button
android:layout_width="match_parent"
android:layout_height="50dp"
android:text="Load more comments"
android:id="@+id/load_more"
android:layout_marginBottom="10dp"
/>
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/listComments"
android:focusable="false"
android:layout_weight="1.0"
android:layout_gravity="center_horizontal" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<ImageView
android:id="@+id/me_img"
android:layout_width="100dp"
android:layout_height="100dp"
android:contentDescription="user"
android:padding="5dp"
/>
<EditText
android:id="@+id/addComment"
android:layout_width="match_parent"
android:layout_height="100dp"
android:layout_marginTop="20dp"
android:layout_marginBottom="10dp"
android:layout_marginRight="20dp"
android:minLines="3"
android:lines="5"
android:gravity="left|top"
android:scrollbars="vertical"
android:inputType="textMultiLine" >
<requestFocus />
</EditText>
</LinearLayout>
谢谢
答案 0 :(得分：0)
我终于理解为什么我的onclick听众根本没有工作/触发，我花了一些时间:-( 我在populateListView方法（第一行）中有这个代码
setContentView(R.layout.activity_comment);
我删除了它，所有听众都会再次工作...... 可能这里有些困惑，说实话我真的不明白： - （