【发布时间】：2011-10-31 17:31:08
【问题描述】：
我正在开发一款 Android 语言词典应用。我正在考虑分两个阶段工作的“收藏夹”按钮：
- 短按将当前查看的单词添加到收藏夹列表中；
- 长按将允许用户查看收藏夹列表（添加的单词）。
我想知道这是否可能，如果可以，请您解释一下如何做？
注意：到目前为止，我只成功地在应用程序中添加了一个收藏图像按钮，当点击它时，它会显示：“选择的单词已添加到收藏夹”。
非常感谢您。
【问题讨论】：
【发布时间】：2011-10-31 17:31:08
【问题描述】：
假设public class FavViewActivity extends ListActivity，您只需像添加 OnClickListener 一样添加 OnLongClickListener：
btnAddFavourite = (ImageButton) findViewById(R.id.btnAddFavourite);
btnAddFavourite.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Add code here to save the favourite, e.g. in the db.
}
});
btnAddFavourite.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
// Open the favourite Activity, which in turn will fetch the saved favourites, to show them.
Intent intent = new Intent(getApplicationContext(), FavViewActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
getApplicationContext().startActivity(intent);
return false;
}
});
在您的数据库中，保留一个收藏表，列出标记为收藏的单词的 ID。
对于创建一个新的 Activity，比如 FavViewActivity，有很多指南。
如需更多帮助，请更具体地说明具体内容，并添加您迄今为止尝试过的内容。 ^_^
【讨论】：
此方法可以使用房间数据库，您可以使用添加到收藏夹并在 RecyclerView 中显示收藏夹您可以将保存在房间数据库中的数据添加到收藏夹中并在 Recyclerview 中检索数据。
viewHolder.fav_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FavoriteList favoriteList=new FavoriteList();
int id=productList.getId();
String image=productList.getImage();
String name=productList.getMame();
favoriteList.setId(id);
favoriteList.setImage(image);
favoriteList.setName(name);
if (MainActivity.favoriteDatabase.favoriteDao().isFavorite(id)!=1){
viewHolder.fav_btn.setImageResource(R.drawable.ic_favorite);
MainActivity.favoriteDatabase.favoriteDao().addData(favoriteList);
}else {
viewHolder.fav_btn.setImageResource(R.drawable.ic_favorite_border_black_24dp);
MainActivity.favoriteDatabase.favoriteDao().delete(favoriteList);
}
}
});房间数据库和所有代码，点击here
【讨论】：
[更新] @JOG：非常感谢。我已经设法使 ViewHistory 工作，但还没有弄清楚如何查看收藏夹列表。更具体地说，请查找随附的我的 ContentView 文件：
package viettien.kadict;
import java.util.ArrayList;
import java.util.Arrays;
import viettien.kadict.R;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.graphics.Color;
import android.net.Uri;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ImageButton;
import android.widget.Toast;
public class ContentView extends Activity {
static final private String CONTENT_TAG = "[Kadict - Content]";
static final private int SHOW_HISTORY_CODE = 0;
static final private int SHOW_FAVOURITE_CODE = 1;
static final private int MENU_BACK = Menu.FIRST;
static final private int MENU_FOWARD = Menu.FIRST+1;
static final private int MENU_LIST = Menu.FIRST+2;
static final private int MENU_HISTORY = Menu.FIRST+3;
private static final String MIMETYPE = "text/html";
private static final String ENCODING = "UTF-8";
private WebView wvContent = null;
private ImageButton btnGoBack = null;
private ImageButton btnGoForward = null;
private ImageButton btnShowHistory = null;
private ImageButton btnAddFavourite = null;
private String mCurrentWord;
private String mSelectedDB;
//private String mSelectedDBName;
private String mContentStyle;
private int mCurrentWordId;
private int mCurrentHistoryIndex = -1;
Menu menu = null;
private ArrayList<String> mWordHistory = null;
private SharedPreferences prefs;
private ProgressDialog pd = null;
// create Menu for Program
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
Log.i(CONTENT_TAG, "menu drawed!!");
// Group ID
int groupId = 0;
// The order position of the item
int menuItemOrder = Menu.NONE;
this.menu=menu;
// Added extra items to make sure there's more than six to
// force the extended menu to appear.
menu.add(groupId, MENU_BACK, menuItemOrder, R.string.menuGoBack);
menu.add(groupId, MENU_FOWARD, menuItemOrder, R.string.menuGoForward);
menu.add(groupId, MENU_LIST, menuItemOrder, R.string.menuList);
menu.add(groupId, MENU_HISTORY, menuItemOrder, R.string.menuHistory);
return true;
}
// process event select Menu
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
// Find which menu item has been selected
switch (item.getItemId()) {
case (MENU_BACK):
{
goBack();
break;
}
case (MENU_FOWARD):
{
goForward();
break;
}
case (MENU_LIST):
{
//menuDictionaryManager();
menuList();
break;
}
case (MENU_HISTORY):
{
break;
}
}
return true;
}
public void menuList()
{
/*
* TODO
* - save history list
*/
Intent i = new Intent();
i.putExtra("word", mCurrentWord);
setResult(RESULT_OK,i);
finish();
}
public void goBack()
{
Log.i(CONTENT_TAG,"go back");
String content = getHistoryContent("back");
showContent(content);
}
public void goForward()
{
Log.i(CONTENT_TAG,"go foward");
String content = getHistoryContent("back");
showContent(content);
}
@Override
public void onPause()
{
super.onPause();
saveHistoryToPreferences();
}
public void saveHistoryToPreferences()
{
if (prefs.getBoolean("saveHistory", true) && mWordHistory != null && mWordHistory.size() >= 1)
{
StringBuilder sbHistory = new StringBuilder();
for (String item : mWordHistory)
{
sbHistory.append(item);
sbHistory.append(",");
}
String strHistory = sbHistory.substring(0, sbHistory.length()-1);
SharedPreferences.Editor editor = prefs.edit();
editor.putString("history", strHistory);
editor.commit();
//Log.i(CONTENT_TAG,"history = " + strHistory);
Log.i(CONTENT_TAG,"History saved!");
}
}
public void loadHistoryFromPreferences()
{
if (prefs.getBoolean("saveHistory", true))
{
String strHistory = prefs.getString("history", "");
Log.i(CONTENT_TAG, "History loaded");
if (strHistory != null && !strHistory.equals(""))
{
mWordHistory = new ArrayList<String>(Arrays.asList(strHistory.split(",")));
}
else
{
if (mWordHistory == null)
{
mWordHistory = new ArrayList<String>();
}
else
{
mWordHistory.clear();
}
}
}
else
{
if (mWordHistory == null)
{
mWordHistory = new ArrayList<String>();
}
else
{
mWordHistory.clear();
}
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.content);
//Log.i(CONTENT_TAG,".................onCreate.................");
Intent i = this.getIntent();
int wordId = i.getIntExtra("id", -1);
mCurrentWord = i.getStringExtra("word");
mSelectedDB = i.getStringExtra("db");
mContentStyle = i.getStringExtra("style");
//Log.i(CONTENT_TAG,"Style from intent = " + mContentStyle);
//Log.d(CONTENT_TAG,"current word = " + mCurrentWord);
prefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
loadHistoryFromPreferences();
wvContent = (WebView) findViewById(R.id.wvContent);
initWebview();
String content = getContentById(wordId);
showContent(content);
btnShowHistory = (ImageButton) findViewById(R.id.btnShowHistory);
btnShowHistory.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Log.i(CONTENT_TAG, "Start showing history..");
/* Intent i = new Intent(v.getContext(), HistoryView.class);
HistoryList hl = new HistoryList(mWordHistory);
i.putExtra("history", hl);*/
startActivityForResult(new Intent(v.getContext(),HistoryView.class), SHOW_HISTORY_CODE);
//showHistory();
}
});
btnGoBack = (ImageButton) findViewById(R.id.btnGoBack);
btnGoBack.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Log.d(CONTENT_TAG, "Start going back");
{
String content = getHistoryContent("back");
if (content == null) // end Activity now
{
menuList();
}
else // go back to previous word
{
showContent(content);
}
menuList();
}
}});
btnGoForward = (ImageButton) findViewById(R.id.btnGoForward);
btnGoForward.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Log.d(CONTENT_TAG, "Start going forward");
goForward();
}
});
btnAddFavourite = (ImageButton) findViewById(R.id.btnAddFavourite);
btnAddFavourite.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Toast toast = Toast.makeText(ContentView.this, R.string.messageWordAddedToFarvourite, Toast.LENGTH_SHORT);
toast.show();
}
});
btnAddFavourite.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
Intent intent = new Intent(getApplicationContext(), SearchActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
getApplicationContext().startActivity(intent);
return false;
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode)
{
case SHOW_HISTORY_CODE:
Log.i(CONTENT_TAG,"resultCode = " + resultCode);
if (resultCode == RESULT_OK) // cleared
{
if (data == null)
{
//loadHistoryFromPreferences();
mWordHistory.clear();
Log.i(CONTENT_TAG,"History cleared");
}
else
{
int id = data.getIntExtra("wordId", 0);
String dict = data.getStringExtra("dict");
Log.i(CONTENT_TAG,"id = " + id + " | dict = " + dict);
if (id > 0 && dict != null)
{
mSelectedDB = dict;
String content = getContentById(id);
//initWebview();
showContent(content);
}
}
}
break;
case SHOW_FAVOURITE_CODE:
break;
}
}
/* @Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
//super.onKeyDown(keyCode, event);
if (keyCode == KeyEvent.KEYCODE_BACK) {
// When the user center presses, let them pick a contact.
Log.d(CONTENT_TAG,"Backkey pressed !!!");
if (mWordHistory != null && mWordHistory.size() > 1 && mCurrentHistoryIndex != 0)
{
String content = getHistoryContent("back");
if (content == null) // end Activity now
{
menuList();
}
else // go back to previous word
{
showContent(content);
}
}
else
{
menuList();
}
return true;
}
return false;
}*/
public void initWebview()
{
setContentView(R.layout.content);
wvContent = (WebView) findViewById(R.id.wvContent);
wvContent.setBackgroundColor(Color.argb(250, 250, 250, 250));
wvContent.setWebViewClient(new WebViewClient()
{
public void onPageFinished(WebView view, String url)
{
if (pd != null)
{
pd.dismiss();
pd = null;
}
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url)
{
Log.i(CONTENT_TAG,"WebView link clicked; url = " + url);
try
{
String arrUrlPart[] = url.split("://");
if (arrUrlPart[0].equals("entry"))
{
String content = getContentByWord(arrUrlPart[1]);
showContent(content);
}
else if (arrUrlPart[0].equals("http"))
{
try {
/*Intent i = new Intent();
ComponentName comp = new ComponentName(
"com.google.android.browser",
"com.google.android.browser.BrowserActivity");
i.setComponent(comp);
i.setAction("android.intent.action.VIEW");
i.addCategory("android.intent.category.BROWSABLE");
ContentURI uri = new ContentURI(url);
i.setData(uri);
startSubActivity(i, 2);*/
startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
} catch (Exception ex) {
// TODO Auto-generated catch block
ex.printStackTrace();
}
}
}
catch (Exception ex)
{
ex.printStackTrace();
}
return true;
}
});
}
public String getHistoryContent(String type)
{
String currentTerm = mSelectedDB + ":" + mCurrentWordId + ":" + mCurrentWord;
Log.i(CONTENT_TAG,"currentTerm = " +currentTerm);
if (mWordHistory == null || mWordHistory.isEmpty())
{
return null;
}
int pos = mWordHistory.indexOf(currentTerm);
Log.i(CONTENT_TAG,"pos = " + pos);
if (pos <= 0)
{
pos = mWordHistory.size();
}
String item = null;
String searchTerm;
if (type.equals("back"))
{
try
{
for (int i = pos-1; i >= 0 ; i--)
{
searchTerm = mWordHistory.get(i);
searchTerm = searchTerm.substring(0,searchTerm.indexOf("::"));
Log.i(CONTENT_TAG,"item = " + mWordHistory.get(i) + " - searchTerm = " + searchTerm);
if (searchTerm.equals(mSelectedDB))
{
item = mWordHistory.get(i);
mCurrentHistoryIndex = i;
break;
}
}
}
catch (Exception ex)
{
Log.i(CONTENT_TAG,"Error in finding history entry");
}
}
else
{
try
{
for (int i = pos; i < mWordHistory.size() ; i++)
{
searchTerm = mWordHistory.get(i);
searchTerm = searchTerm.substring(0,searchTerm.indexOf("::"));
Log.i(CONTENT_TAG,"item = " + mWordHistory.get(i) + " - searchTerm = " + searchTerm);
if (searchTerm.equals(mSelectedDB))
{
item = mWordHistory.get(i);
mCurrentHistoryIndex = i;
break;
}
}
}
catch (Exception ex)
{
Log.i(CONTENT_TAG,"Error in finding history entry");
}
}
if (item != null) // found previous item
{
Log.i(CONTENT_TAG,"item index = " + mCurrentHistoryIndex);
String arrPart[] = item.split(":");
Uri uri = Uri.parse("content://viettien.kadict.KadictProvider/dict/" + arrPart[0] + "/contentId/" + arrPart[1]);
Log.i(CONTENT_TAG,"History uri = " + uri.toString());
Cursor result = managedQuery(uri,null,null,null,null);
String content;
if (result != null)
{
result.moveToFirst();
content = Utility.decodeContent(result.getString(result.getColumnIndex("content")));
content = formatContent(content);
mSelectedDB = arrPart[0];
mCurrentWordId = Integer.parseInt(arrPart[1]);
mCurrentWord = arrPart[2];
return content;
}
else
{
return null;
}
}
else
{
return null;
}
}
public String getContentById(int id)
{
Uri uri = Uri.parse("content://viettien.kadict.KadictProvider/dict/" + mSelectedDB + "/contentId/" + id);
Cursor result = managedQuery(uri,null,null,null,null);
String content;
if (result != null)
{
result.moveToFirst();
content = Utility.decodeContent(result.getString(result.getColumnIndex("content")));
mCurrentWordId = result.getInt(result.getColumnIndex("id"));
mCurrentWord = result.getString(result.getColumnIndex("word"));
}
else // Word not found
{
content = getString(R.string.errorWordNotFound);
mCurrentWordId = -1;
mCurrentWord = "";
}
content = formatContent(content);
return content;
}
public String getContentByWord(String word)
{
Uri uri = Uri.parse("content://viettien.kadict.KadictProvider/dict/" + mSelectedDB + "/contentWord/" + word);
Log.i(CONTENT_TAG,"uri = " + uri.toString());
Cursor result = managedQuery(uri,null,null,null,null);
String content;
if (result != null && result.getCount() > 0)
{
result.moveToFirst();
content = Utility.decodeContent(result.getString(result.getColumnIndex("content")));
mCurrentWordId = result.getInt(result.getColumnIndex("id"));
mCurrentWord = result.getString(result.getColumnIndex("word"));
}
else
{
content = getString(R.string.errorWordNotFound) + word;
mCurrentWordId = -1;
mCurrentWord = "";
}
content = formatContent(content);
return content;
}
public void saveHistory()
{
String item = mSelectedDB + "::" + mCurrentWordId + "::" + mCurrentWord;
if (mWordHistory.indexOf(item) == -1 && mCurrentWordId != -1) // new item
{
mWordHistory.add(item);
mCurrentHistoryIndex = mWordHistory.size();
if (menu != null)
{
menu.findItem(MENU_FOWARD).setEnabled(false);
if (mWordHistory.size() == 1)
{
menu.findItem(MENU_BACK).setEnabled(false);
}
}
//Log.i(CONTENT_TAG,"new item added " + item);
}
}
public String formatContent(String content)
{
StringBuilder htmlData = new StringBuilder();
htmlData.append("<html><meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\"/>\n");
if (mContentStyle != null && !mContentStyle.equals(""))
{
htmlData.append("<head><style type=\"text/css\">"+mContentStyle+"</style></head>\n");
}
htmlData.append("<body><font face=\"Arial\">");
htmlData.append(content);
htmlData.append("</font></body></html>");
return htmlData.toString();
}
public void showContent(String content)
{
if (content != null)
{
pd = ProgressDialog.show(this, "Working...", "Loading content", true,false);
saveHistory();
wvContent.loadDataWithBaseURL (null, content, MIMETYPE, ENCODING,"about:blank");
}
}
}
【讨论】：
-
我更新了我的帖子以反映您的代码。我必须要求您更具体地说明什么不起作用。您究竟在哪里遇到问题？
-
@JOG：你花时间帮助我真是太好了。实际上，不起作用的是：长按按钮时，不会出现添加到收藏夹的单词列表。作为测试，我尝试将“SearchActivity.class”更改为“HistoryView.class”（该类已定义），并且“收藏夹”按钮在长按时起作用：它调用历史记录。所以我想我必须添加一个收藏夹类，不是吗？非常感谢。
-
是的，如果要在全屏页面中显示收藏夹，则需要通过扩展 Activity 类来创建一个新类。首先，您必须在单击时将收藏夹保存在数据库中（或保存内容的任何位置），然后在新活动中从数据库中获取它们。我不知道有任何内置的喜欢的功能可以为您做到这一点。我没有阅读您的所有代码，因为我想没有错，您只需要继续编码:) 我在答案中添加了一些链接。另外，请参阅：stackoverflow.com/questions/how-to-ask
-
@JOG：现在这是一项非常艰巨的任务，但我会尽力做到这一点:)。如果我有如此棘手（或“简单”）的问题，请允许我稍后再打扰您。非常感谢您的帮助。
-
没问题！一开始我们都是n00bs。并随时将我的帖子标记为答案。 ^_^ 请参阅我的答案中的链接。创建一个新的活动并不比你迄今为止所做的任何事情都难。