我尝试为列表视图创建上下文菜单,但是当我在列表项上“长按”时,应用程序将关闭此跟踪:
FATAL EXCEPTION: main
java.lang.NullPointerException
at com.android.internal.policy.impl.PhoneWindow$DecorView$ActionModeCallbackWrapper.onCreateActionMode(PhoneWindow.java:2445)
at com.android.internal.app.ActionBarImpl$ActionModeImpl.dispatchOnCreate(ActionBarImpl.java:708)
at com.android.internal.app.ActionBarImpl.startActionMode(ActionBarImpl.java:392)
at android.app.Activity.onWindowStartingActionMode(Activity.java:4380)
at com.android.internal.policy.impl.PhoneWindow$DecorView.startActionMode(PhoneWindow.java:2151)
at com.android.internal.policy.impl.PhoneWindow$DecorView.startActionModeForChild(PhoneWindow.java:2138)
at android.view.ViewGroup.startActionModeForChild(ViewGroup.java:573)
at android.view.ViewGroup.startActionModeForChild(ViewGroup.java:573)
at android.view.ViewGroup.startActionModeForChild(ViewGroup.java:573)
at android.view.View.startActionMode(View.java:3558)
at android.widget.AbsListView.performLongPress(AbsListView.java:2570)
at android.widget.AbsListView$CheckForLongPress.run(AbsListView.java:2530)
at android.os.Handler.handleCallback(Handler.java:605)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4340)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
我浏览了很多示例和教程,但我找不到决定。 Android API 14。
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
linkButton = (Button) findViewById(R.id.link_button);
debugTxt = (TextView) findViewById(R.id.debugText);
lv = (ListView) this.findViewById(R.id.filelist);
registerForContextMenu(lv);
linkButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
onClickLink();
}
});
mDbxAcctMgr = DbxAccountManager.getInstance(getApplicationContext(), appKey, appSecret);
}
@Override
protected void onResume() {
super.onResume();
if (mDbxAcctMgr.hasLinkedAccount()) {
showLinkedView();
doDropboxTest();
} else {
showUnlinkedView();
}
}
private void onClickLink() {
mDbxAcctMgr.startLink((Activity)this, REQUEST_LINK_TO_DBX);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_LINK_TO_DBX) {
if (resultCode == Activity.RESULT_OK) {
doDropboxTest();
} else {
debugTxt.setText("Link to Dropbox failed or was cancelled.");
}
} else {
super.onActivityResult(requestCode, resultCode, data);
}
}
private void doDropboxTest() {
try {
// Create DbxFileSystem for synchronized file access.
DbxFileSystem dbxFs = DbxFileSystem.forAccount(mDbxAcctMgr.getLinkedAccount());
items = new ArrayList<String>();
// Print the contents of the root folder. This will block until we can
// sync metadata the first time.
List<DbxFileInfo> infos = dbxFs.listFolder(DbxPath.ROOT);
debugTxt.setText("Contents of app folder:\n");
for (DbxFileInfo info : infos) {
info.path.toString();
if (info.isFolder) {
items.add(info.path.getName() + "/");
} else {
items.add(info.path.getName());
}
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, items);
lv.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
//lv.setLongClickable(true);
lv.setAdapter(adapter);
} catch (IOException e) {
debugTxt.setText("Dropbox test failed: " + e);
}
}
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<item
android:id="@+id/edit"
android:title="@string/edit" />
<item
android:id="@+id/remove"
android:title="@string/remove" />
<item
android:id="@+id/change"
android:title="@string/change" />
</menu>
寻求帮助!
答案 0 :(得分:1)
当您使用registerForContextMenu()
为上下文菜单注册视图时,活动将设置为接收onCreateContextMenu()
来电。移除lv.setOnCreateContextMenuListener()
来电,并将onCreateContextMenu()
方法移至活动。
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
linkButton = (Button) findViewById(R.id.link_button);
debugTxt = (TextView) findViewById(R.id.debugText);
lv = (ListView) this.findViewById(R.id.filelist);
registerForContextMenu(lv);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, items);
lv.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
lv.setAdapter(adapter);
linkButton.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
onClickLink();
}
});
mDbxAcctMgr = DbxAccountManager.getInstance(getApplicationContext(), appKey, appSecret);
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo)
{ //here u set u rute
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.login, menu);
}
此外,当你为上下文菜单注册了lv时,你不需要调用lv.setLongClickable()
。
答案 1 :(得分:1)
结账了吗
android:choiceMode="multipleChoiceModal"
而不是
android:choiceMode="multipleChoice"
这是我犯过的错误。
答案 2 :(得分:1)
如果ListView发生此问题,您使用mlistView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL)。
你应该设置那个选择模式:mlistView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE) - 它让我兴奋。