Android的NULL menuInfo在onCreateContextMenu和onContextItemSelected只能与onListItemClick手动调用openContextMenu。长按作品 [英] Android NULL menuInfo in onCreateContextMenu and onContextItemSelected only with manual call to openContextMenu in onListItemClick. Long click works

问题描述

我已经经历了很多这里的职位分析，并没有发现过像我的问题。

基本上我试图调用 openContextMenu（L）在 onListItemClick 。这样做可以创建一个没有 menuInfo 的上下文菜单。执行长按会正常工作。执行长按之后，我的code将开始工作，并实际获得 menuInfo 不为null。

我有一个 ListActivity 是充满了 SimpleCursorAdapter 从抓取数据的SQL 。

在我的onCreate我 registerForContextMenu（getListView（））。
我一直在使用也尝试 registerForContextMenu（L）之前的 openContextMenu（L）电话。

任何帮助将是AP preciated！谢谢你。

下面是我的code的样本：

 公共类MY_Activity扩展ListActivity {...@覆盖
公共无效的onCreate（捆绑savedInstanceState）{    ...    UpdateTable（）;
    registerForContextMenu（getListView（））;
}...@覆盖
公共无效onListItemClick（ListView中升，观景，INT位置，长的id）{
    super.onListItemClick（L，视图，位置ID）;    //这并不工作，除非长时间点击先发生
    // registerForContextMenu（升）; //尝试在这里做太
    openContextMenu（升）;
    // unregisterForContextMenu（升）; //然后注销这里...
}@覆盖
公共无效onCreateContextMenu（文本菜单菜单视图V，ContextMenuInfo menuInfo）{
    super.onCreateContextMenu（菜单，V，menuInfo）;    // menuInfo将为空在这里。    menu.setHeaderTitle（上下文菜单）;
    menu.add（0，v.getId（），0，1）;
    menu.add（0，v.getId（），0，二）;
    menu.add（0，v.getId（），0，三）;
}@覆盖
公共布尔onContextItemSelected（菜单项项）{
    AdapterContextMenuInfo信息=（AdapterContextMenuInfo）item.getMenuInfo（）;
    如果（资讯== NULL）{
        Log.e（，空上下文菜单intem信息...）;
        返回false;
    }
}公共无效UpdateTable（）{
    光标= DatabaseHelper_Main.GetCursor（添加my_id）;
    CursorAdapter的=新SimpleCursorAdapter（这一点，R.layout.my_listview_entry，
            光标，字段，fieldResources，0）;
    setListAdapter（CursorAdapter的）;
}...
 

解决方案

今天我有一个非常类似的问题，并修复出乎意料地简单，但我不明白为什么，但我会在这里反正张贴。

  @覆盖
公共无效onItemClick（适配器视图＆LT;＆GT;母公司，观景，INT位置，长的id）{
    m_contextMenu = TRUE;
    registerForContextMenu（父）;
    m_listView.showContextMenuForChild（视图）;
    unregisterForContextMenu（父）;
    m_contextMenu = FALSE;
}
 

我用m_contextMenu布尔值指示正在显示的上下文菜单中，我有一个返回false m_contextMenu这样的上下文菜单不显示（如果onItemLongClick（）返回true，它不会显示是真实的onItemLongClickListener上下文菜单）。

I have parsed through a lot of the posts here and haven't found anything quite like my problem.

Basically I am trying to call openContextMenu(l) in onListItemClick. Doing so creates a context menu with no menuInfo. Performing a long click will work correctly. After the long click is performed, my code will start working and actually get a menuInfo that is not null.

I have a ListActivity that is filled with a SimpleCursorAdapter which grabs data from SQL.

In my onCreate I registerForContextMenu(getListView()). I have also tried using registerForContextMenu(l) just before the openContextMenu(l) call.

Any help would be appreciated! Thanks.

Here is a sample of my code:

public class MY_Activity extends ListActivity {

...

@Override
public void onCreate(Bundle savedInstanceState) {

    ...

    UpdateTable();
    registerForContextMenu(getListView());
}

...

@Override
public void onListItemClick(ListView l, View view, int position, long id) {
    super.onListItemClick(l, view, position, id);

    //THIS DOESNT WORK UNLESS A LONG CLICK HAPPENS FIRST
    //registerForContextMenu(l);  //Tried doing it here too
    openContextMenu(l);
    //unregisterForContextMenu(l); //Then unregistering here...
}

@Override  
public void onCreateContextMenu(ContextMenu menu, View v,ContextMenuInfo menuInfo) { 
    super.onCreateContextMenu(menu, v, menuInfo);  

    //menuInfo will be null here.

    menu.setHeaderTitle("Context Menu");
    menu.add(0, v.getId(), 0, "One");  
    menu.add(0, v.getId(), 0, "Two");
    menu.add(0, v.getId(), 0, "Three");
}

@Override  
public boolean onContextItemSelected(MenuItem item) {
    AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
    if(info == null) {
        Log.e("","NULL context menu intem info...");
        return false;
    }
}

public void UpdateTable() {
    cursor = DatabaseHelper_Main.GetCursor(my_id);
    cursorAdapter = new SimpleCursorAdapter(this, R.layout.my_listview_entry, 
            cursor, fields, fieldResources, 0);
    setListAdapter(cursorAdapter);
}

...

解决方案

I had a very similar issue today, and the fix was unexpectedly simple but I don't understand why, but I'll post it here anyway.

@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
    m_contextMenu = true;
    registerForContextMenu(parent);
    m_listView.showContextMenuForChild(view);
    unregisterForContextMenu(parent);
    m_contextMenu = false;
}

I use the m_contextMenu boolean to indicate that the context menu is being shown, I have an onItemLongClickListener that returns false if m_contextMenu is true so that the context menu does show up (if onItemLongClick() returns true, it won't show the context menu).

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