Question

我有FragmentActivity使用SherlockActionBar和支持库v4。

主布局中有ListFragment。点击列表项会打开一个新的ListFragment，可以部分滑入视图。如果您长按某些列表项，则会显示一个上下文菜单，其中包含两个选项。第一个选项会显示dialog EditText框，Button'在尝试打开时会崩溃。

如果我删除EditText行和Button行（除非您使用findViewById声明这些行），系统会弹出一个空的dialog。但由于某种原因，它不喜欢对话框的内容（按钮/框）。任何人都可以看看LogCat，看看为什么？ null行是setText行。如果我将其评论出来，则按钮的onClickListner会变为null。

以下是该代码和logcat的代码。

public boolean onContextItemSelected(android.view.MenuItem item) {

        if (item.getGroupId() == 2) {

            switch (item.getItemId()) {

            case 1:


case 1:

                if (Rateit.isUserLoggedIn == true) {

                    final Dialog dialog = new Dialog(getActivity());
                    dialog.setTitle("Edit Review");
                    dialog.show();

                    final EditText etEdit = (EditText) dialog
                            .findViewById(R.id.etEditReview);

                    etEdit.setText(reviewWords);

                    Button bInsert = (Button) dialog.findViewById(R.id.bInsert);
                    bInsert.setOnClickListener(new OnClickListener() {

                        public void onClick(View v) {

                            clickedReview = etEdit.getText().toString();

                            if (clickedReview.equals("")) {

                                Toast.makeText(getActivity(),
                                        "Please add something first.",
                                        Toast.LENGTH_SHORT).show();

                            } else {
                                newReview = etEdit.getText().toString();
                                new EditCommentTask().execute();

                                InputMethodManager imm = (InputMethodManager) getActivity()
                                        .getSystemService(
                                                Context.INPUT_METHOD_SERVICE);
                                imm.hideSoftInputFromWindow(
                                        etEdit.getWindowToken(), 0);

                                dialog.dismiss();

                            }

                        }
                    });

                }

                return true;

logcat的：

03-06 10:29:08.527: E/AndroidRuntime(10438): FATAL EXCEPTION: main
03-06 10:29:08.527: E/AndroidRuntime(10438): java.lang.NullPointerException
03-06 10:29:08.527: E/AndroidRuntime(10438):    at com.---.---.RateReviewFragment.onContextItemSelected(RateReviewFragment.java:901)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at android.support.v4.app.FragmentManagerImpl.dispatchContextItemSelected(FragmentManager.java:1933)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:360)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at com.actionbarsherlock.app.SherlockFragmentActivity.onMenuItemSelected(SherlockFragmentActivity.java:211)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at com.android.internal.policy.impl.PhoneWindow$DialogMenuCallback.onMenuItemSelected(PhoneWindow.java:3633)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:735)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:149)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:874)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at com.android.internal.view.menu.MenuDialogHelper.onClick(MenuDialogHelper.java:167)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at com.android.internal.app.AlertController$AlertParams$3.onItemClick(AlertController.java:941)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at android.widget.AdapterView.performItemClick(AdapterView.java:298)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at android.widget.AbsListView.performItemClick(AbsListView.java:1100)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at android.widget.AbsListView$PerformClick.run(AbsListView.java:2749)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at android.widget.AbsListView$1.run(AbsListView.java:3423)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at android.os.Handler.handleCallback(Handler.java:725)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at android.os.Handler.dispatchMessage(Handler.java:92)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at android.os.Looper.loop(Looper.java:137)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at android.app.ActivityThread.main(ActivityThread.java:5226)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at java.lang.reflect.Method.invokeNative(Native Method)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at java.lang.reflect.Method.invoke(Method.java:511)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
03-06 10:29:08.527: E/AndroidRuntime(10438):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

看起来好像你没有夸大对话框的XML，我想你有一个用于该对话框的XML，所以你应该这样做：

LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = inflater.inflate(R.layout.instructions, (ViewGroup) activity.findViewById(R.id.layout_root));
builder = new AlertDialog.Builder(mContext);
builder.setView(layout);
Button bInsert = (Button) layout.findViewById(R.id.bInsert);
alertDialog = builder.create();
alertDialog.show();

你要把

放在哪里

 mContext=this;

onCreate（）中的

（如果你在你的活动中）

Answer 2

查看您的代码，似乎您可能忘记为新创建的Dialog（使用setContentView(the_layout_file)）设置布局（包含您的小部件）。如果您不这样做，那么在对话框中搜索并尝试使用这些小部件将抛出NullPointerException。

崩溃在片段上面的`onContextItemSelected`上

2 个答案: