检测哪个选定的项目(在ListView中)生成了ContextMenu (安卓)
检测哪个选定的项目(在ListView中)生成了ContextMenu (安卓)
提问于 2010-02-24 04:08:12
我有一个ListView，它将允许用户长按一个项目，以获得上下文菜单。我遇到的问题是无法确定他们长时间按下了哪个ListItem。我试过这样做：
myListView.setOnCreateContextMenuListener(new OnCreateContextMenuListener() {
@Override public void onCreateContextMenu(ContextMenu menu, final View v, ContextMenuInfo menuInfo) {
menu.add("Make Toast")
.setOnMenuItemClickListener(new OnMenuItemClickListener() {
@Override public boolean onMenuItemClick(MenuItem item) {
String toastText = "You clicked position " + ((ListView)v).getSelectedItemPosition();
Toast.makeText(DisplayScheduleActivity.this, toastText, Toast.LENGTH_SHORT).show();
return true;
}
});
}
});但它会一直挂起，直到弹出一个ANR。我怀疑在菜单创建之后，ListItem不再被选中。
看起来你可以监控点击或长点击，然后记录点击的项目：
mArrivalsList.setOnItemLongClickListener(new OnItemLongClickListener() {
@Override public boolean onItemLongClick(AdapterView<?> parent, View v, int position, long id) {
// record position/id/whatever here
return false;
}
});但对我来说，这主要是乱七八糟的。有人对此有更好的解决方案吗？
回答 8
Stack Overflow用户
回答已采纳
发布于 2010-02-24 04:20:40
我就是这么做的。在我的onCreateContextMenu(...)方法中，我将ContextMenu.ContextMenuInfo转换为AdapterView.AdapterContextMenuInfo。从那里，您可以获得targetView，您可以将其再次转换为小部件。完整的代码可以在HomeActivity.java中找到，请查找onCreateContextMenu(...)方法。
@Override
public void onCreateContextMenu(ContextMenu contextMenu,
View v,
ContextMenu.ContextMenuInfo menuInfo) {
AdapterView.AdapterContextMenuInfo info =
(AdapterView.AdapterContextMenuInfo) menuInfo;
selectedWord = ((TextView) info.targetView).getText().toString();
selectedWordId = info.id;
contextMenu.setHeaderTitle(selectedWord);
contextMenu.add(0, CONTEXT_MENU_EDIT_ITEM, 0, R.string.edit);
contextMenu.add(0, CONTEXT_MENU_DELETE_ITEM, 1, R.string.delete);
}请注意，我将所选文本以及select id存储在私有字段中。因为UI是线程受限的，所以我知道selectedWord和selectedWordId字段对于以后的操作是正确的。
Stack Overflow用户
发布于 2010-02-24 05:50:25
首先，我想知道使用View.setOnCreateContextMenuListener()会不会让事情变得过于复杂。如果使用Activity.registerForContextMenu()，事情会变得容易得多，因为这样就可以只使用Activity.onCreateContextMenu()和Activity.onContextItemSelected()来处理所有的菜单事件。这基本上意味着您不必定义所有这些匿名内部类来处理每个事件；您只需覆盖一些活动方法来处理这些上下文菜单事件。
其次，绝对有更简单的方法来检索当前选定的项。您所需要做的就是保持对ListView或用于填充它的Adapter的引用。您可以使用ContextMenuInfo作为AdapterContextMenuInfo来获取项目的位置；然后可以使用ListView.getItemAtPosition()或Adapter.getItem()来检索明确链接到所单击内容的Object。例如，假设我使用的是Activity.onCreateContextMenu()，我可以这样做：
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
// Get the info on which item was selected
AdapterContextMenuInfo info = (AdapterContextMenuInfo) menuInfo;
// Get the Adapter behind your ListView (this assumes you're using
// a ListActivity; if you're not, you'll have to store the Adapter yourself
// in some way that can be accessed here.)
Adapter adapter = getListAdapter();
// Retrieve the item that was clicked on
Object item = adapter.getItem(info.position);
}
@Override
public boolean onContextItemSelected(MenuItem item) {
// Here's how you can get the correct item in onContextItemSelected()
AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
Object item = getListAdapter().getItem(info.position);
}Stack Overflow用户
发布于 2011-08-10 14:05:21
这是关于如何创建上下文菜单的另一种方法n如何删除此处选择的项目是整个代码
public class SimpleJokeList extends Activity {
public static final int Upload = Menu.FIRST + 1;
public static final int Delete = Menu.FIRST + 2;
int position;
ListView lv;
EditText jokeBox;
Button addJoke;
MyAdapter adapter;
private ArrayAdapter<String> mAdapter;
private ArrayList<String> mStrings = new ArrayList<String>();
String jokesToBeAdded;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.simplejokeui);
lv=(ListView)findViewById(R.id.jokelist);
addJoke=(Button)findViewById(R.id.addjoke);
jokeBox=(EditText)findViewById(R.id.jokebox);
mAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mStrings);
registerForContextMenu(lv);
listItemClicked();
addJokes();
private void addJokes() {
// TODO Auto-generated method stub
addJoke.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
jokesToBeAdded=jokeBox.getText().toString();
if(jokesToBeAdded.equals("")){
Toast.makeText(getApplicationContext(), "please enter some joke", Toast.LENGTH_LONG).show();
}
else{
lv.setAdapter(mAdapter);
mAdapter.add(jokesToBeAdded);
jokeBox.setText(null);
}
}
});
}
private void listItemClicked() {
// TODO Auto-generated method stub
lv.setOnItemLongClickListener(new OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
// TODO Auto-generated method stub
position=arg2;
return false;
}
});
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
// TODO Auto-generated method stub
super.onCreateContextMenu(menu, v, menuInfo);
populateMenu(menu);
menu.setHeaderTitle("Select what you wanna do");
}
private void populateMenu(ContextMenu menu) {
// TODO Auto-generated method stub
menu.add(Menu.NONE, Upload, Menu.NONE, "UPLOAD");
menu.add(Menu.NONE, Delete, Menu.NONE, "DELETE");
}
@Override
public boolean onContextItemSelected(MenuItem item)
{
return (applyMenuChoice(item) || super.onContextItemSelected(item));
}
private boolean applyMenuChoice(MenuItem item) {
// TODO Auto-generated method stub
switch (item.getItemId())
{
case Delete:
String s=mAdapter.getItem(position);
mAdapter.remove(s);
// position--;
Toast.makeText(getApplicationContext(),"Congrats u HAve Deleted IT", Toast.LENGTH_LONG).show();
return (true);
}
return false;
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/2321332
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