如何将数据添加到 listView 的自定义 BaseAdapter - Android
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【中文标题】如何将数据添加到 listView 的自定义 BaseAdapter - Android【英文标题】：How to add data to custom BaseAdapter for listView - Android 【发布时间】：2013-08-23 06:37:15 【问题描述】：我有一个自定义 BaseAdapter 类，它为 cmets、用户名和数字创建视图。此 BaseAdapter 从 An AsyncTask 接收此信息。当用户到达 listView 的底部时，AsyncTask 运行。问题是 BaseAdapter 不会添加新数据。当我尝试添加新数据时，它会删除列表中的当前数据，然后添加新数据。我希望它保留所有数据，并将数据添加到 listView 的底部。所有这些类都在同一个活动中。这是我当前的代码。
class CreateCommentLists extends BaseAdapter
Context ctx_invitation;
String[] listComments;
String[] listNumbers;
String[] listUsernames;
public CreateCommentLists(String[] comments, String[] usernames, String[] numbers, DashboardActivity context)
super();
ctx_invitation = context;
listComments = comments;
listNumbers = usernames;
listUsernames = numbers;
@Override
public int getCount()
if(null == listComments)
return 0;
// TODO Auto-generated method stub
return listComments.length;
@Override
public Object getItem(int position)
// TODO Auto-generated method stub
return listComments[position];
@Override
public long getItemId(int position)
// TODO Auto-generated method stub
return 0;
@Override
public View getView(final int position, View convertView, ViewGroup parent)
// TODO Auto-generated method stub
View v = null;
try
String inflater = Context.LAYOUT_INFLATER_SERVICE;
LayoutInflater li = (LayoutInflater)ctx_invitation.getSystemService(inflater);
v = li.inflate(R.layout.list_item, null);
TextView commentView = (TextView)v.findViewById(R.id.listComment);
TextView NumbersView = (TextView)v.findViewById(R.id.listNumber);
TextView usernamesView = (TextView)v.findViewById(R.id.listPostedBy);
Button usernameButton = (Button)v.findViewById(R.id.listUsernameButton);
Button numberButton = (Button)v.findViewById(R.id.listNumberButton);
commentView.setText(listComments[position]);
NumbersView.setText(listNumbers[position]);
usernamesView.setText(listUsernames[position]);
usernameButton.setOnClickListener(new View.OnClickListener()
public void onClick(View view)
Intent i = new Intent(getApplicationContext(), ProfileActivity.class);
i.putExtra("usernameOfProfile",listUsernames[position]);
startActivity(i);
finish();
);
numberButton.setOnClickListener(new View.OnClickListener()
public void onClick(View arg0)
Intent i = new Intent(getApplicationContext(), ProfileActivity.class);
i.putExtra("NumberProfile",listNumbers[position]);
startActivity(i);
finish();
);
catch(Exception e)
e.printStackTrace();
return v;
public void add(String[] comments, String[] usernames,
String[] numbers)
listComments = comments;
listNumbers = usernames;
listUsernames = numbers;
public int getCount1()
if(null == listComments)
return 0;
// TODO Auto-generated method stub
return listComments.length;
public Object getItem1(int position)
// TODO Auto-generated method stub
return listComments[position];
public long getItemId1(int position)
// TODO Auto-generated method stub
return 0;
public View getView1(final int position, View convertView, ViewGroup parent)
// TODO Auto-generated method stub
View v = null;
try
String inflater = Context.LAYOUT_INFLATER_SERVICE;
LayoutInflater li = (LayoutInflater)ctx_invitation.getSystemService(inflater);
v = li.inflate(R.layout.list_item, null);
TextView commentView = (TextView)v.findViewById(R.id.listComment);
TextView NumbersView = (TextView)v.findViewById(R.id.listNumber);
TextView usernamesView = (TextView)v.findViewById(R.id.listPostedBy);
Button usernameButton = (Button)v.findViewById(R.id.listUsernameButton);
Button numberButton = (Button)v.findViewById(R.id.listNumberButton);
commentView.setText(listComments[position]);
NumbersView.setText(listNumbers[position]);
usernamesView.setText(listUsernames[position]);
usernameButton.setOnClickListener(new View.OnClickListener()
public void onClick(View view)
Intent i = new Intent(getApplicationContext(), ProfileActivity.class);
i.putExtra("usernameOfProfile",listUsernames[position]);
startActivity(i);
finish();
);
numberButton.setOnClickListener(new View.OnClickListener()
public void onClick(View arg0)
Intent i = new Intent(getApplicationContext(), ProfileActivity.class);
i.putExtra("NumberProfile",listNumbers[position]);
startActivity(i);
finish();
);
catch(Exception e)
e.printStackTrace();
return v;
final CreateCommentLists mycmlist = new CreateCommentLists(comments, usernames, numbers, DashboardActivity.this);
lstComments = (ListView)findViewById(android.R.id.list);
lstComments.setAdapter(mycmlist);
final ProgressDialog progDailog = new ProgressDialog(DashboardActivity.this);
class loadComments extends AsyncTask<JSONObject, String, JSONObject>
@Override
protected void onPreExecute()
super.onPreExecute();
progDailog.setIndeterminate(false);
progDailog.setCancelable(true);
progDailog.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
progDailog.show();
progDailog.setContentView(R.layout.progress_circle);
@Override
protected void onProgressUpdate(String... values)
super.onProgressUpdate(values);
protected JSONObject doInBackground(JSONObject... params)
JSONObject json2 = CollectComments.collectComments(usernameforcomments, offsetNumber);
return json2;
@Override
protected void onPostExecute(JSONObject json2)
try
if (json2.getString(KEY_SUCCESS) != null)
registerErrorMsg.setText("");
String res2 = json2.getString(KEY_SUCCESS);
if(Integer.parseInt(res2) == 1)
JSONArray commentArray = json2.getJSONArray(KEY_COMMENT);
String comments[] = new String[commentArray.length()];
for ( int i=0; i<commentArray.length(); i++ )
comments[i] = commentArray.getString(i);
JSONArray numberArray = json2.getJSONArray(KEY_NUMBER);
String numbers[] = new String[numberArray.length()];
for ( int i=0; i<numberArray.length(); i++ )
numbers[i] = numberArray.getString(i);
JSONArray usernameArray = json2.getJSONArray(KEY_USERNAME);
String usernames[] = new String[usernameArray.length()];
for ( int i=0; i<usernameArray.length(); i++ )
usernames[i] = usernameArray.getString(i);
mycmlist.add(comments,usernames,numbers);
mycmlist.notifyDataSetChanged();
//end if key is == 1
else
// Error in registration
registerErrorMsg.setText(json2.getString(KEY_ERROR_MSG));
//end else
//end if
//end try
catch (JSONException e)
e.printStackTrace();
//end catch
progDailog.dismiss();
mainListView = (ListView) findViewById(android.R.id.list);
class EndlessScrollListener implements OnScrollListener
private int i = 0;
private int visibleThreshold = 5;
private int previousTotal = 0;
private boolean loading = true;
public EndlessScrollListener()
public EndlessScrollListener(int visibleThreshold)
this.visibleThreshold = visibleThreshold;
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount)
if ((firstVisibleItem + visibleItemCount) == totalItemCount)
new loadComments().execute();
mainListView.smoothScrollToPosition(0);
@Override
public void onScrollStateChanged(AbsListView view, int scrollState)
mainListView.setOnScrollListener(new EndlessScrollListener());
【问题讨论】：
我在您的 BaseAdapter 实现中没有看到add 方法...
add方法应该是什么？
对于线路：mycmlist.add(comments,usernames,numbers); 那个方法在哪里？我在您发布的代码中没有看到它。或者，也许我只是个盲人。 :P
它不存在，我没有创建一个大声笑。这一定是它根本不起作用的原因。 add 方法应该是什么？它是如何工作的？
好吧，如果没有 add 方法，那么您的代码在尝试编译时必须抛出错误。它根本不应该运行。
【参考方案1】：
你试试这个：
public class Comment
String username;
String content;
String number;
类适配器：
public class CommentAdapter extends BaseAdapter
private List<Comment> listComment;
private Context context;
public CommentAdapter(List<Comment> listComment, Context context)
super();
this.listComment = listComment;
this.context = context;
@Override
public int getCount()
return listComment.size();
@Override
public Comment getItem(int position)
return listComment.get(position);
@Override
public long getItemId(int arg0)
return 0;
@Override
public View getView(int position, View convertView, ViewGroup parent)
View v = convertView;
if (v == null)
LayoutInflater mInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = mInflater.inflate(R.layout.comment_item, null);
final TextView textViewUsername = (TextView) v
.findViewById(R.id.comment_Username);
final TextView textViewNumber = (TextView) v
.findViewById(R.id.comment_number);
final TextView textViewContent = (TextView) v
.findViewById(R.id.comment_Content);
final String username = listComment.get(position).getUsername();
final String number= listComment.get(position).getNumber();
String content = listComment.get(position).getContent();
textViewUsername.setText(username);
textViewNumber.setText(number);
textViewContent.setText(content);
return v;
当您需要向列表添加新评论时。只需创建新评论并添加到 listComment(listComment.add(newComment))，然后调用 adapter.notifyDataSetChanged();
【讨论】：
但在 Asynctask 中，它将多个 cmets、用户名和数字收集到字符串中。每次运行 asynctask 时创建多个 cmets 时，它不会创建 1 条新评论 您可以在AsyncTask内多次调用listComment(listComment.add(newComment))【参考方案2】：
package com.example.baseadapter;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends Activity implements OnItemClickListener
public static final String[] title = new String[]
"image 1", "image 2", "image 3", "image 4"
;
public static final Integer[] images =
R.drawable.aa, R.drawable.bb, R.drawable.cc, R.drawable.cc, R.drawable.dd
;
ListView listview;
List<RowItem> rowItems;
@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rowItems = new ArrayList<RowItem>();
for (int i = 0; i < title.length; i++)
RowItem item = new RowItem(images[i], title[i]);
rowItems.add(item);
listview = (ListView)findViewById(R.id.listview);
customBaseAdapter cba = new customBaseAdapter(this, rowItems);
listview.setAdapter(cba);
listview.setOnItemClickListener(this);
@Override
public boolean onCreateOptionsMenu(Menu menu)
// it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3)
Toast.makeText(getApplicationContext(), "item selected", Toast.LENGTH_LONG).show();
public class customBaseAdapter extends BaseAdapter
Context context;
List<RowItem> rowItem;
public customBaseAdapter(Context context, List<RowItem> listItem)
this.context = context;
rowItem = listItem;
Log.d("const", "const");
@Override
public int getCount()
Log.d("count", "count");
return rowItem.size();
@Override
public Object getItem(int arg0)
Log.d("item", "item");
return rowItem.get(arg0);
@Override
public long getItemId(int position)
Log.d("const", "item id");
return rowItem.indexOf(getItem(position));
@Override
public View getView(int position, View convertView, ViewGroup parent)
Log.d("const", "getview");
LayoutInflater inflater = (LayoutInflater)context
.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
RowItem rowitem = (RowItem)getItem(position);
TextView textForTitle;
ImageView imgForImage;
convertView = inflater.inflate(R.layout.inflate, null);
textForTitle = (TextView)convertView.findViewById(R.id.textview);
imgForImage = (ImageView)convertView.findViewById(R.id.imageview);
textForTitle.setText(rowitem.getTitle());
imgForImage.setImageResource(rowitem.getImageId());
return convertView;
public class RowItem
int imageId;
String title;
public RowItem(int imageId, String title)
this.imageId = imageId;
this.title = title;
public int getImageId()
return imageId;
public void setImageId(int imageId)
this.imageId = imageId;
public String getTitle()
return title;
public void setStringTitle(String title)
this.title = title;
@Override
public String toString()
return title;
【讨论】：
请添加一些说明，说明此代码如何解决问题，并正确格式化。 所有这些代码都以这种格式为我工作....如果您有任何理解问题，请告诉我，我会帮助您。以上是关于如何将数据添加到 listView 的自定义 BaseAdapter - Android的主要内容，如果未能解决你的问题，请参考以下文章