Android工具栏上下文菜单用于ListView项。

Question

Android工具栏上下文菜单用于ListView项。

androidandroid-listviewmenucontextmenuandroid-toolbar

3

我正在寻求如何在工具栏中为ListView项目实现类似WhatsApp的上下文菜单的帮助。到目前为止，我找到的所有教程都是关于弹出对话框的，这不是我想要的。是否有人可以帮助我或提供链接和教程？谢谢：）

- qwertz

1个回答

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可以查看英文原文，
原文链接

- Anton Kovalyov · Accepted Answer

请查看这个官方的Android指南

编辑：

使用上下文操作模式

对于提供上下文操作的视图，通常应在以下两种事件之一（或两者都）上调用上下文操作模式：

用户长按视图。
用户选择视图中的复选框或类似的UI组件。

如何调用上下文操作模式以及为每个操作定义行为取决于您的设计。基本上有两种设计：

针对单个任意视图的上下文操作。
针对ListView或GridView中的项目组的批量上下文操作（允许用户选择多个项目并对它们执行操作）。

启用单个视图的上下文操作模式

Implement the ActionMode.Callback interface. In its callback methods, you can specify the actions for the contextual action bar, respond to click events on action items, and handle other lifecycle events for the action mode.

private ActionMode.Callback mActionModeCallback = new             ActionMode.Callback() {

// Called when the action mode is created; startActionMode() was called
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
    // Inflate a menu resource providing context menu items
    MenuInflater inflater = mode.getMenuInflater();
    inflater.inflate(R.menu.context_menu, menu);
    return true;
}

// Called each time the action mode is shown. Always called after onCreateActionMode, but
// may be called multiple times if the mode is invalidated.
@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
    return false; // Return false if nothing is done
}

// Called when the user selects a contextual menu item
@Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
    switch (item.getItemId()) {
        case R.id.menu_share:
            shareCurrentItem();
            mode.finish(); // Action picked, so close the CAB
            return true;
        default:
            return false;
    }
}

// Called when the user exits the action mode
@Override
public void onDestroyActionMode(ActionMode mode) {
    mActionMode = null;
}
};

Call startActionMode() when you want to show the bar (such as when the user long-clicks the view).

someView.setOnLongClickListener(new View.OnLongClickListener() {
// Called when the user long-clicks on someView
public boolean onLongClick(View view) {
    if (mActionMode != null) {
        return false;
    }

    // Start the CAB using the ActionMode.Callback defined above
    mActionMode = getActivity().startActionMode(mActionModeCallback);
    view.setSelected(true);
    return true;
}
});

在ListView或GridView中启用批量上下文操作

如果您在ListView或GridView（或AbsListView的其他扩展）中有一组项目，并希望允许用户执行批处理操作，则应该：

Implement the AbsListView.MultiChoiceModeListener interface and set it for the view group with setMultiChoiceModeListener(). In the listener's callback methods, you can specify the actions for the contextual action bar, respond to click events on action items, and handle other callbacks inherited from the ActionMode.Callback interface.

Call setChoiceMode() with the CHOICE_MODE_MULTIPLE_MODAL argument.

ListView listView = getListView();
listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
listView.setMultiChoiceModeListener(new MultiChoiceModeListener() {

@Override
public void onItemCheckedStateChanged(ActionMode mode, int position,
                                      long id, boolean checked) {
    // Here you can do something when items are selected/de-selected,
    // such as update the title in the CAB
}

@Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
    // Respond to clicks on the actions in the CAB
    switch (item.getItemId()) {
        case R.id.menu_delete:
            deleteSelectedItems();
            mode.finish(); // Action picked, so close the CAB
            return true;
        default:
            return false;
    }
}

@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
    // Inflate the menu for the CAB
    MenuInflater inflater = mode.getMenuInflater();
    inflater.inflate(R.menu.context, menu);
    return true;
}

@Override
public void onDestroyActionMode(ActionMode mode) {
    // Here you can make any necessary updates to the activity when
    // the CAB is removed. By default, selected items are deselected/unchecked.
}

@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
    // Here you can perform updates to the CAB due to
    // an invalidate() request
    return false;
}
});

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