Question

出于某种原因，当我长按EditText框（例如粘贴数据）时，它会尝试调出上下文菜单。

这是LogCat：

01-26 12:00:22.243: E/AndroidRuntime(22300): FATAL EXCEPTION: main
01-26 12:00:22.243: E/AndroidRuntime(22300): java.lang.NullPointerException
01-26 12:00:22.243: E/AndroidRuntime(22300):    at com.---.---.Comments.onCreateContextMenu(Comments.java:352)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.View.createContextMenu(View.java:7781)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.View.createContextMenu(View.java:7789)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.View.createContextMenu(View.java:7789)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at com.android.internal.view.menu.ContextMenuBuilder.show(ContextMenuBuilder.java:81)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at com.android.internal.policy.impl.PhoneWindow$DecorView.showContextMenuForChild(PhoneWindow.java:2201)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.ViewGroup.showContextMenuForChild(ViewGroup.java:612)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.ViewGroup.showContextMenuForChild(ViewGroup.java:612)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.ViewGroup.showContextMenuForChild(ViewGroup.java:612)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.ViewGroup.showContextMenuForChild(ViewGroup.java:612)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.ViewGroup.showContextMenuForChild(ViewGroup.java:612)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.widget.AbsListView.showContextMenuForChild(AbsListView.java:2969)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.ViewGroup.showContextMenuForChild(ViewGroup.java:612)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.View.showContextMenu(View.java:4154)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.View.performLongClick(View.java:4123)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.widget.TextView.performLongClick(TextView.java:7875)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.view.View$CheckForLongPress.run(View.java:16945)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.os.Handler.handleCallback(Handler.java:615)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.os.Handler.dispatchMessage(Handler.java:92)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.os.Looper.loop(Looper.java:137)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at android.app.ActivityThread.main(ActivityThread.java:4745)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at java.lang.reflect.Method.invokeNative(Native Method)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at java.lang.reflect.Method.invoke(Method.java:511)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
01-26 12:00:22.243: E/AndroidRuntime(22300):    at dalvik.system.NativeStart.main(Native Method)
01-26 12:00:22.250: W/ActivityManager(291):   Force finishing activity com.---.rat---/.Comments

我的ContextMenu的代码，其中包含导致NullPointer的行：

@Override
public void onCreateContextMenu(ContextMenu menu, View v,
        ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);
    android.view.MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.comments_context, menu);
    menu.setHeaderTitle("Available Actions");

    android.view.MenuItem Edit = menu.findItem(R.id.editComment);
    android.view.MenuItem Delete = menu.findItem(R.id.deleteComment);

    AdapterContextMenuInfo info = (AdapterContextMenuInfo) menuInfo;
    int position = info.position;
    ListView lv = (ListView) v;
    int firstVisible = lv.getFirstVisiblePosition();
    View rowView = lv.getChildAt(position - firstVisible);

  // this is the line where there is a null pointer.  (Obviousness in an `EditText` box,  this `TextView` doesn't exist!

    ReviewUser = ((TextView) rowView.findViewById(R.id.labelReviewCommentUser)).getText().toString();
    ReviewComment = ((TextView) rowView.findViewById(R.id.labelReviewComment)).getText().toString();


    // Other Stuff Edited Out

}

EditText框在我的onCreate：

中创建

EtComment = (EditText) findViewById(R.id.etTweetComment);

onCreate的最后是：

registerForContextMenu（getListView（））;

另外，就在我声明EditText的地方，我设置了listview：

LayoutInflater inflater = this.getLayoutInflater();
        ViewGroup header = (ViewGroup) inflater.inflate(
                R.layout.comment_header, listView, false);

        listView = getListView();
        listView.addHeaderView(header, null, false);
        listView.setClickable(false);
        listView.setTextFilterEnabled(true);

EditText框位于ListView标题中（comment_header）。不确定这是否重要。

主要问题：为什么要通过长按EditText来注册ContextMenu？

修改/更新 ：

我相信CommonsWare现在回答这个问题我正在努力解决它：

请将v与getListView（）进行比较，看看它们是否相同对象与否。如果不是，只需链接到超类。

你是如何实现这一目标的？当我打电话给我时，registerForContextMenu(getListView());我相信，它会始终根据该代码打开ContextMenu ListView，所以我怎么能比较我是否长期按ListView与EditText框相比？

Answer 1

它可以弹出一个ContextMenu对话框来处理EditText小部件上的长按。通常，此菜单包含以下内容：

剪切
复制
粘贴
全选
选择文字

由于平台版本的各种差异，以及在各种设备上实施的OEM ui，在EditText上长按时所采取的操作取决于您运行的设备。因此，在不了解您所使用的设备的情况下，我只能大致了解操作系统可以弹出上下文菜单的原因。

Longpressing EditText会导致崩溃

1 个答案: