我的MainActivity是Google Maps Activity，我有2个片段叫做＃34; LoginForm＆＃34;和＆＃34; appSettings＆＃34;。我可以从MainActivity切换到2个片段，但我无法切换回MainActivity。我尝试过fragment.addToBackStack（），但它没有做任何事情。任何的想法？以下是导航抽屉的代码。
public void selectedDrawerItem(MenuItem menuItem){
Class fragmentClass = null;
FrameLayout frameLayoutMap = (FrameLayout) findViewById(R.id.main_container_login);
FragmentManager fragmentManager = getSupportFragmentManager();
// For every new Fragment, add in Switch statement.
switch(menuItem.getItemId()) {
case R.id.nav_geomap:
fragmentClass = MapsActivity.class;
break;
case R.id.nav_login:
Log.d(TAG, "Accessed fragment: menuItem nav_login");
//frameLayoutMap.removeAllViews();
fragmentClass = LoginForm.class;
break;
case R.id.nav_settings:
Log.d(TAG, "Accessed fragment: menuItem nav_settings");
// frameLayoutMap.removeAllViews();
fragmentClass = appSettings.class;
break;
}
try
{
fragment = (Fragment) fragmentClass.newInstance();
}
catch (Exception e){
e.printStackTrace();
}
fragmentManager.beginTransaction().replace(R.id.map, fragment).commit();
menuItem.setChecked(true);
setTitle(menuItem.getTitle());
mDrawerLayout.closeDrawers();
}
答案 0 :(得分：0)
试试这个
CursorKind.CLASS_DECL SomeClass SomeClass [2 :1 - 14 :2] main.cpp
CursorKind.CXX_ACCESS_SPEC_DECL [4 :1 - 4 :8] main.cpp
CursorKind.CXX_METHOD sum int (int, int) [5 :5 - 8 :6] main.cpp _ZN9SomeClass3sumEii
CursorKind.PARM_DECL x int [5 :13 - 5 :18] main.cpp _ZZN9SomeClass3sumEiiE1x
CursorKind.PARM_DECL y int [5 :20 - 5 :25] main.cpp _ZZN9SomeClass3sumEiiE1y
CursorKind.COMPOUND_STMT [6 :5 - 8 :6] main.cpp
CursorKind.RETURN_STMT [7 :9 - 7 :21] main.cpp
CursorKind.BINARY_OPERATOR int [7 :16 - 7 :21] main.cpp
CursorKind.UNEXPOSED_EXPR x int [7 :16 - 7 :17] main.cpp
CursorKind.DECL_REF_EXPR x int [7 :16 - 7 :17] main.cpp
CursorKind.UNEXPOSED_EXPR y int [7 :20 - 7 :21] main.cpp
CursorKind.DECL_REF_EXPR y int [7 :20 - 7 :21] main.cpp
CursorKind.CXX_METHOD sum_def int (int, int) [10 :5 - 13 :6] main.cpp _ZN9SomeClass7sum_defEii
CursorKind.PARM_DECL x int [10 :17 - 10 :22] main.cpp _ZZN9SomeClass7sum_defEiiE1x
CursorKind.PARM_DECL y int [10 :24 - 10 :33] main.cpp _ZZN9SomeClass7sum_defEiiE1y
CursorKind.INTEGER_LITERAL int [10 :32 - 10 :33] main.cpp
CursorKind.COMPOUND_STMT [11 :5 - 13 :6] main.cpp
CursorKind.RETURN_STMT [12 :9 - 12 :21] main.cpp
CursorKind.BINARY_OPERATOR int [12 :16 - 12 :21] main.cpp
CursorKind.UNEXPOSED_EXPR x int [12 :16 - 12 :17] main.cpp
CursorKind.DECL_REF_EXPR x int [12 :16 - 12 :17] main.cpp
CursorKind.UNEXPOSED_EXPR y int [12 :20 - 12 :21] main.cpp
CursorKind.DECL_REF_EXPR y int [12 :20 - 12 :21] main.cpp
CursorKind.FUNCTION_DECL main int () [17 :1 - 26 :2] main.cpp main
CursorKind.COMPOUND_STMT [18 :1 - 26 :2] main.cpp
CursorKind.DECL_STMT [19 :5 - 19 :22] main.cpp
CursorKind.VAR_DECL i int [19 :5 - 19 :14] main.cpp _ZZ4mainE1i
CursorKind.INTEGER_LITERAL int [19 :13 - 19 :14] main.cpp
CursorKind.VAR_DECL j int [19 :16 - 19 :21] main.cpp _ZZ4mainE1j
CursorKind.INTEGER_LITERAL int [19 :20 - 19 :21] main.cpp
CursorKind.DECL_STMT [20 :5 - 20 :17] main.cpp
CursorKind.VAR_DECL x SomeClass [20 :5 - 20 :16] main.cpp _ZZ4mainE1x
CursorKind.TYPE_REF class SomeClass SomeClass [20 :5 - 20 :14] main.cpp
CursorKind.CALL_EXPR SomeClass SomeClass [20 :15 - 20 :16] main.cpp
CursorKind.CALL_EXPR sum int [21 :5 - 21 :19] main.cpp
ARG=CursorKind.INTEGER_LITERAL
ARG=CursorKind.INTEGER_LITERAL
CursorKind.MEMBER_REF_EXPR sum <bound member function type> [21 :5 - 21 :10] main.cpp
CursorKind.DECL_REF_EXPR x SomeClass [21 :5 - 21 :6] main.cpp
CursorKind.INTEGER_LITERAL int [21 :11 - 21 :13] main.cpp
CursorKind.INTEGER_LITERAL int [21 :15 - 21 :18] main.cpp
CursorKind.CALL_EXPR sum_def int [22 :5 - 22 :18] main.cpp
ARG=CursorKind.INTEGER_LITERAL
ARG=CursorKind.UNEXPOSED_EXPR
CursorKind.MEMBER_REF_EXPR sum_def <bound member function type> [22 :5 - 22 :14] main.cpp
CursorKind.DECL_REF_EXPR x SomeClass [22 :5 - 22 :6] main.cpp
CursorKind.INTEGER_LITERAL int [22 :15 - 22 :17] main.cpp
CursorKind.UNEXPOSED_EXPR int [0 :0 - 0 :0] None
CursorKind.CALL_EXPR sum_def int [23 :5 - 23 :23] main.cpp
ARG=CursorKind.INTEGER_LITERAL
ARG=CursorKind.INTEGER_LITERAL
CursorKind.MEMBER_REF_EXPR sum_def <bound member function type> [23 :5 - 23 :14] main.cpp
CursorKind.DECL_REF_EXPR x SomeClass [23 :5 - 23 :6] main.cpp
CursorKind.INTEGER_LITERAL int [23 :15 - 23 :17] main.cpp
CursorKind.INTEGER_LITERAL int [23 :19 - 23 :22] main.cpp
CursorKind.CALL_EXPR sum int [24 :5 - 24 :16] main.cpp
ARG=CursorKind.UNEXPOSED_EXPR i
ARG=CursorKind.UNEXPOSED_EXPR j
CursorKind.MEMBER_REF_EXPR sum <bound member function type> [24 :5 - 24 :10] main.cpp
CursorKind.DECL_REF_EXPR x SomeClass [24 :5 - 24 :6] main.cpp
CursorKind.UNEXPOSED_EXPR i int [24 :11 - 24 :12] main.cpp
CursorKind.DECL_REF_EXPR i int [24 :11 - 24 :12] main.cpp
CursorKind.UNEXPOSED_EXPR j int [24 :14 - 24 :15] main.cpp
CursorKind.DECL_REF_EXPR j int [24 :14 - 24 :15] main.cpp
CursorKind.RETURN_STMT [25 :5 - 25 :13] main.cpp
CursorKind.INTEGER_LITERAL int [25 :12 - 25 :13] main.cpp