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我正在自定义WebView内创建自定义上下文操作栏（CAB）。嵌套上下文操作栏
我的要求是，从第一个CAB中选择一个特定的选项将打开第二个CAB。这是最终目标：
我做了这一点，但选择工作不正常。我知道这看起来是正确的，但如果用户点击任何其他三个图标，这就是结果：
如果用户按下任意的四个初始图标后触及的选择，该应用程序由于空指针异常而崩溃。
当用户触摸选择的动作之后挥之不去的选择，应用程序试图访问ActionMode（姑且称之为firstActionMode）创建与图标的CAB，以无效/刷新。但是，创建具有颜色的CAB时（）导致空指针异常，firstActionMode将被销毁。
为了扫清选择，我发现，调用clearFocus()内onDestroyActionMode(firstActionMode)方法做这项工作就好了。
private class CustomActionModeCallback extends ActionMode.Callback {
@Override
public void onDestroyActionMode(ActionMode mode) {
clearFocus();
}
}
然而，当这是实现，当secondActionMode创建了CAB的选择并不坚持：
从这个角度选择色彩实际上产生所需的功能。然而，虽然这个“有效”，但它（最不幸）并不符合我的要求。当显示由secondActionMode创建的CAB时，我需要选择保持可见和功能。
这里是我的自定义类（
WebView）及其嵌套
ActionMode是代码
public class CustomWebView extends WebView {
private ActionMode.Callback mActionModeCallback;
@Override
public ActionMode startActionMode(Callback callback) {
ViewParent parent = getParent();
if (parent == null) {
return null;
}
if (callback instanceof HighlightActionModeCallback) {
mActionModeCallback = callback;
} else {
mActionModeCallback = new CustomActionModeCallback();
}
return parent.startActionModeForChild(this, mActionModeCallback);
}
private class CustomActionModeCallback implements 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.first_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) {
// This method is called when the handlebars are moved.
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.copy:
// Do stuff
break;
case R.id.bookmark:
// Do stuff
break;
case R.id.highlight:
startActionMode(new HighlightActionModeCallback());
break;
case R.id.note:
// Do stuff
break;
default:
return false;
}
mode.finish(); // Action picked, so close the CAB
return true;
}
// Called when the user exits the action mode
@Override
public void onDestroyActionMode(ActionMode mode) {
clearFocus(); // This is commented in the first four screens.
}
}
private class HighlightActionModeCallback implements 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.highlight_colors, 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) {
// This method is called when the handlebars are moved.
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) {
mode.finish(); // Action picked, so close the CAB
return true;
}
// Called when the user exits the action mode
@Override
public void onDestroyActionMode(ActionMode mode) {
// Remove the selection highlight and handles.
clearFocus();
}
}
}
如何这个问题能解决？任何和所有的帮助表示赞赏。