我试图在列表视图中单击按钮时更改按钮的文本，我尝试通过自定义适配器执行此操作。使用日志调用onclick只是文本似乎没有改变：
这是我的适配器代码：
public class UserViewerAdapter extends BaseAdapter {
public List<DatabaseUser> _list;
public List<UserResponse> _listForSearch;
private final Activity mContext;
private ConfirmManager confirmManager;
private int query;
private Button isFriend;
// database helper
private DatabaseHelper db;
private static LayoutInflater inflater = null;
public UserViewerAdapter(Activity context, List<DatabaseUser> list) {
mContext = context;
_list = list;
//establishing db
db = new DatabaseHelper(mContext);
confirmManager = new ConfirmManager();
query = 0;
}
public UserViewerAdapter( List<UserResponse> list, Activity context) {
mContext = context;
_listForSearch = list;
query = 1;
//establishing db
db = new DatabaseHelper(mContext);
confirmManager = new ConfirmManager();
}
@Override
public int getCount() {
if(query == 0) {
return _list.size();
}
return _listForSearch.size();
}
@Override
public Object getItem(int position) {
if(query == 0) {
return _list.get(position);
}
return _listForSearch.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater inflater = mContext.getLayoutInflater();
v = inflater.inflate(R.layout.users_layout, null);
}
ImageView userImage = (ImageView) v.findViewById(R.id.userImage);
TextView text = (TextView) v.findViewById(R.id.label);
isFriend = (Button) v.findViewById(R.id.btnFriend);
String isFriendText;
//coming from search
if(query == 1) {
if (_listForSearch != null && _listForSearch.size() > 0) {
text.setText(_listForSearch.get(position).getName());
}
Picasso.with(mContext).setLoggingEnabled(true);
// String pictureToAdd = Constants.USER_IMAGES + _listForSearch.get(position).getPicId();
// String photo = _listForSearch.get(position).get_picture();
// Log.d(Constants.DEBUG, "THE photo IS " + photo);
// Log.d(Constants.DEBUG, "THE constant IS " + Constants.USER_IMAGES);
// if (photo.equals("default.jpg")) {
Picasso.with(mContext).load(R.drawable.default_profile_image).resize(50, 50).into(userImage);
isFriendText = "Add Friend";
if(_listForSearch.get(position).isFriend()) {
isFriendText = "Remove Friend";
}
isFriend.setText(isFriendText);
final String finalIsFriendText = isFriendText;
isFriend.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Remove friend
callConfirmAddOrRemove(_listForSearch.get(position), finalIsFriendText);
Log.d(Constants.DEBUG, "clicked friend button " + finalIsFriendText);
}
});
}
return v;
}
private void changeText(String finalIsFriendText) {
String newTextToFill = "";
if(finalIsFriendText.equals("Remove Friend")) {
newTextToFill = "Add Friend";
}
if(finalIsFriendText.equals("Add Friend")) {
newTextToFill = "Remove Friend";
}
Log.d(Constants.DEBUG, "changing text of friend button " + newTextToFill);
isFriend.setText(newTextToFill);
notifyDataSetChanged();
}
private void callConfirmAddOrRemove(UserResponse userResponse, String finalIsFriendText) {
boolean dlg = confirmManager.Confirm(mContext, mContext.getString(R.string.remove_friend), mContext.getString(R.string.details_confirmation)
+ "\n" + mContext.getString(R.string.details_info),
mContext.getString(R.string.submit), mContext.getString(R.string.cancel), addOrRemove(userResponse, finalIsFriendText),
cancelPost());
}
private Runnable addOrRemove(final UserResponse userResponse, final String finalIsFriendText) {
return new Runnable() {
public void run() {
sendToDb(userResponse, finalIsFriendText);
}
};
}
private void sendToDb(UserResponse userResponse, String finalIsFriendText) {
Log.d(Constants.DEBUG, "sending to db friend change");
String uid, name, picid;
int points, totalshifts, totalhours, isguarding, isfriend;
uid = userResponse.getUserId();
name = userResponse.getName();
picid = userResponse.getPictureId();
points = userResponse.getTotalPoints();
totalshifts = userResponse.getTotalShifts();
totalhours = userResponse.getTotalHours();
isguarding = 0;
if(userResponse.isCheckedIn()) {
isguarding = 1;
}
//have to do the opposite since trying to add or remove 3 means newly added friend, 2 means newly removed friend
isfriend = 3;
if(userResponse.isFriend()) {
isfriend = 2;
}
DatabaseUser addOrRemoveUser = new DatabaseUser(uid, name, picid, points, totalshifts,totalhours, isguarding, isfriend);
db.updateFriend(addOrRemoveUser);
changeText(finalIsFriendText);
notifyDataSetChanged();
}
private Runnable cancelPost() {
return new Runnable() {
public void run() {
Log.d(Constants.DEBUG, "Canceled posting item");
}
};
}
}
这是xml（我在itemclick工作时将list focus设置为false for listview）：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="5dip" >
<!-- ListRow Left side Thumbnail image -->
<LinearLayout android:id="@+id/thumbnail"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="3dip"
android:layout_alignParentLeft="true"
android:layout_marginRight="5dip">
<ImageView
android:id="@+id/userImage"
android:layout_width="50dip"
android:layout_height="50dip"
android:focusable="false"
android:focusableInTouchMode="false"/>
</LinearLayout>
<!-- Name-->
<TextView
android:id="@+id/label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@+id/thumbnail"
android:layout_centerInParent="true"
android:layout_marginLeft="25dip"
android:textColor="#040404"
android:typeface="sans"
android:textSize="15dip"
android:textStyle="bold"
android:text="DEFAULT NAME"
android:focusable="false"
android:focusableInTouchMode="false"/>
<!-- Friend button -->
<Button android:id="@+id/btnFriend"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/friends"
android:layout_marginRight="5dp"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:textSize="15dip"
android:focusable="false"
android:focusableInTouchMode="false"/>
</RelativeLayout>
答案 0 :(得分：1)
您正尝试在单独的线程中更改文本，但是，只有 UI主线程可以更改TextViews和Buttons等视图。
要解决此问题，您可以使用runOnUiThread
runOnUiThread(new Runnable() {
public void run() {
// Update Button Text
}
});
所以，在sendToDB中，更改
changeText(finalIsFriendText);
的
runOnUiThread(new Runnable() {
public void run() {
changeText(finalIsFriendText);
}
});
runOnUIThread是来自java.lang.Runnable的方法，可以在Docs
在UI线程上运行指定的操作。如果当前线程是 UI线程，然后立即执行操作。如果是当前的 线程不是UI线程，操作被发布到事件队列 UI线程。
因此，它是一个函数，它将您输入的Runnable作为参数，并在UI线程中运行它，从而可以更改任何其他线程中的UI元素。
答案 1 :(得分：1)
在getView的点击监听器中，方法为：
callConfirmAddOrRemove(_listForSearch.get(position), finalIsFriendText);
您无法正确position，因此您必须使用按钮position定义最终position或绑定isFriend标记。
[<强>更新
isFriend.setTag(position); //this is inside getView
然后在你的听众中：
int position = (int)v.getTag(); //this position will be correct one
希望这有帮助！
答案 2 :(得分：0)
我认为问题是isFriend用于更新文本，使用另一个来执行此操作。
还要注意 UI主线程问题。
private Button btnToUpdate;
@Override
public void onClick(View v) {
btnToUpdate = v; //save which button to update
//Remove friend
callConfirmAddOrRemove(_listForSearch.get(position), finalIsFriendText);
Log.d(Constants.DEBUG, "clicked friend button " + finalIsFriendText);
}
private void changeText(String finalIsFriendText) {
String newTextToFill = "";
if(finalIsFriendText.equals("Remove Friend")) {
newTextToFill = "Add Friend";
}
if(finalIsFriendText.equals("Add Friend")) {
newTextToFill = "Remove Friend";
}
Log.d(Constants.DEBUG, "changing text of friend button " + newTextToFill);
btnToUpdate.setText(newTextToFill); //use btnToUpdate to update text
notifyDataSetChanged();
}