如何根据 ListActivity 中长按的项目设置特定的上下文菜单?
我有一个列表活动,我选择手动添加第一个项目,即“添加新项目...”。
我已经使用 registerForContextMenu(getListView());
直接在 onCreate
中注册了整个列表视图的上下文菜单。
构建上下文菜单时,系统会调用onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo)
。 View v
是listView,我找不到方法来知道listview 中的哪个项目被长按。
我可以创建一个 xml 布局,其中包含“添加新项目...”的布局,并在之后添加一个列表视图,该列表视图将由活动填充,并且会对上下文菜单做出反应,但我确信有一种无需任何 xml 布局即可解决此问题的方法。
我尝试使用 registerForContextMenu
注册列表视图中的每个视图,这有效,但是列表视图不再响应触摸。
这是我的活动代码清单:
public class AMain extends ListActivity {
private List<String> pregList;
private List<Long> pregIds;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
pregList = new ArrayList<String>();
pregIds = new ArrayList<Long>();
registerForContextMenu(getListView());
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
// TODO: hide the menu for the 1st item!!
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.context_menu, menu);
}
@Override
public boolean onContextItemSelected(MenuItem item) {
AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
Logger.d("id = "+info.id);
switch (item.getItemId()) {
case R.id.menu_show:
showPregnancy((int) info.id);
return true;
case R.id.menu_edit:
editPregnancy((int) info.id);
return true;
case R.id.menu_delete:
//TODO: do the deletion
return true;
default:
return super.onContextItemSelected(item);
}
}
protected void onStart() {
super.onStart();
clearPregList();
loadPregList();
getListView().setAdapter(new PregnancyListAdapter(this));
}
void clearPregList() {
pregList.clear();
pregIds.clear();
}
void loadPregList() {
PregnanciesDbAdapter db = new PregnanciesDbAdapter(this);
db.open();
Cursor c = db.getPregnancies();
if (c != null) {
do {
pregList.add(c.getString(c.getColumnIndex(PregnanciesDbAdapter.KEY_PREG_NOM)));
pregIds.add(c.getLong(c.getColumnIndex(PregnanciesDbAdapter.KEY_PREG_ROWID)));
} while (c.moveToNext());
c.close();
}
db.close();
}
private class PregnancyListAdapter extends BaseAdapter {
private Context context;
public PregnancyListAdapter(Context ctx) {
context = ctx;
}
@Override
public int getCount() {
return pregList.size()+1;
}
@Override
public Object getItem(int position) {
if (position == 0) { // add button
return getString(R.string.addPreg);
} else {
return pregList.get(position-1);
}
}
@Override
public long getItemId(int position) {
if (position == 0) {
return -1;
}
return pregIds.get(position-1);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LinearLayout itemLayout;
itemLayout= (LinearLayout) LayoutInflater.from(context).inflate(R.layout.homelist_item_pregnancy, parent, false);
ImageView logo = (ImageView) itemLayout.findViewById(R.id.logo);
TextView pregName = (TextView) itemLayout.findViewById(R.id.pregName);
if (position == 0) {
itemLayout.setFocusable(false);
itemLayout.setFocusableInTouchMode(false);
pregName.setText(getString(R.string.addPreg));
} else {
logo.setVisibility(View.INVISIBLE);
pregName.setText(pregList.get(position-1));
}
itemLayout.setId(position);
return itemLayout;
}
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
if (position == 0) {
startActivity(prepareIntent(AShowPregnancy.class, 0));
} else {
showPregnancy(position-1);
}
}
void showPregnancy(int pregId) {
startActivity(prepareIntent(AShowPregnancy.class, pregId));
}
void editPregnancy(int pregId) {
startActivity(prepareIntent(ANewPregnancy.class, pregId));
}
Intent prepareIntent(Class<?> className, int pregId) {
Intent i = new Intent(this, className);
if (pregId > 0) {
PregnanciesDbAdapter db = new PregnanciesDbAdapter(this);
db.open();
Pregnancy p = db.load(pregIds.get(pregId));
db.close();
i.putExtra(C.EXTRA_PREGNANCY, p);
}
return i;
}
}
感谢您的阅读。希望你能帮忙。
I have a list activity, and I chose to manually add the first item which is "add new item...".
I have registered the context menu for the whole listview, using registerForContextMenu(getListView());
straight into the onCreate
.
When the context menu is build, the system calls onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo)
. The View v
is the listView, and I cannot find a way to know which item in the listview is being long-pressed.
I could create a xml layout, with a layout for the "add new item..." and add a listview after, which would be populated by the activity, and that would react to the context menu, but I'm sure there is a way to solve this problem without any xml layout.
I have tried to register each view inside my listview using registerForContextMenu
, which works, however the listview doesn't respond to touch anymore.
Here is my activity code listing:
public class AMain extends ListActivity {
private List<String> pregList;
private List<Long> pregIds;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
pregList = new ArrayList<String>();
pregIds = new ArrayList<Long>();
registerForContextMenu(getListView());
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
// TODO: hide the menu for the 1st item!!
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.context_menu, menu);
}
@Override
public boolean onContextItemSelected(MenuItem item) {
AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
Logger.d("id = "+info.id);
switch (item.getItemId()) {
case R.id.menu_show:
showPregnancy((int) info.id);
return true;
case R.id.menu_edit:
editPregnancy((int) info.id);
return true;
case R.id.menu_delete:
//TODO: do the deletion
return true;
default:
return super.onContextItemSelected(item);
}
}
protected void onStart() {
super.onStart();
clearPregList();
loadPregList();
getListView().setAdapter(new PregnancyListAdapter(this));
}
void clearPregList() {
pregList.clear();
pregIds.clear();
}
void loadPregList() {
PregnanciesDbAdapter db = new PregnanciesDbAdapter(this);
db.open();
Cursor c = db.getPregnancies();
if (c != null) {
do {
pregList.add(c.getString(c.getColumnIndex(PregnanciesDbAdapter.KEY_PREG_NOM)));
pregIds.add(c.getLong(c.getColumnIndex(PregnanciesDbAdapter.KEY_PREG_ROWID)));
} while (c.moveToNext());
c.close();
}
db.close();
}
private class PregnancyListAdapter extends BaseAdapter {
private Context context;
public PregnancyListAdapter(Context ctx) {
context = ctx;
}
@Override
public int getCount() {
return pregList.size()+1;
}
@Override
public Object getItem(int position) {
if (position == 0) { // add button
return getString(R.string.addPreg);
} else {
return pregList.get(position-1);
}
}
@Override
public long getItemId(int position) {
if (position == 0) {
return -1;
}
return pregIds.get(position-1);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LinearLayout itemLayout;
itemLayout= (LinearLayout) LayoutInflater.from(context).inflate(R.layout.homelist_item_pregnancy, parent, false);
ImageView logo = (ImageView) itemLayout.findViewById(R.id.logo);
TextView pregName = (TextView) itemLayout.findViewById(R.id.pregName);
if (position == 0) {
itemLayout.setFocusable(false);
itemLayout.setFocusableInTouchMode(false);
pregName.setText(getString(R.string.addPreg));
} else {
logo.setVisibility(View.INVISIBLE);
pregName.setText(pregList.get(position-1));
}
itemLayout.setId(position);
return itemLayout;
}
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
if (position == 0) {
startActivity(prepareIntent(AShowPregnancy.class, 0));
} else {
showPregnancy(position-1);
}
}
void showPregnancy(int pregId) {
startActivity(prepareIntent(AShowPregnancy.class, pregId));
}
void editPregnancy(int pregId) {
startActivity(prepareIntent(ANewPregnancy.class, pregId));
}
Intent prepareIntent(Class<?> className, int pregId) {
Intent i = new Intent(this, className);
if (pregId > 0) {
PregnanciesDbAdapter db = new PregnanciesDbAdapter(this);
db.open();
Pregnancy p = db.load(pregIds.get(pregId));
db.close();
i.putExtra(C.EXTRA_PREGNANCY, p);
}
return i;
}
}
Thanks for reading. Hope you can help.
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评论(1)
哦,上帝,又来了。我自己发现了如何做到这一点,而且这比简单更容易。
我讨厌我自己:)
Oh, god, again. I found out myself how to do it, and it was easier than easy.
I hate myself :)