如何将 activity 转换为片段
how to convert activity to fragment
我正在尝试使用导航抽屉，我有一个包含 ListView 的 Activity 代码。我想将所有 Activity 转换为 Fragment，我该怎么做？
有人可以 post 我的代码转换成 Fragment 吗？
这是我的 activity 代码：
public class SceltaDiete extends ActionBarActivity{
ListView sceltadieta;
Database d = new Database(getApplicationContext());
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.scelta_activity);
sceltadieta = (ListView) findViewById(R.id.scelta_dieta);
final Cursor c = d.scelta();
CursorLoader(c);
String from[] = {Codice.DATI_ID,
Codice.DATI_NOME_DIETA};
int to[] = {R.id.record_id,
R.id.record_nome};
@SuppressWarnings("deprecation")
SimpleCursorAdapter sca = new SimpleCursorAdapter(this,
R.layout.singolo_elemento,
c, from, to);
sceltadieta = (ListView) findViewById(R.id.scelta_dieta);
sceltadieta.setAdapter(sca);
sceltadieta.setClickable(true);
sceltadieta.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@SuppressWarnings("deprecation")
public void onItemClick(AdapterView<?> parent, View v, int position,
long id) {
TextView txtId = (TextView) v.findViewById(R.id.record_id);
TextView txtNome = (TextView) v.findViewById(R.id.record_nome);
String nomeString = (String) txtNome.getText();
String elemIdString = (String) txtId.getText();
final int elemIdInt = Integer.parseInt(elemIdString);
switch(elemIdInt){
case 1:
d.cancella();
d.insertscelta(nomeString);
break;
case 2:
d.cancella();
d.insertscelta(nomeString);
break;
case 3:
d.cancella();
d.insertscelta(nomeString);
break;
case 4:
d.cancella();
d.insertscelta(nomeString);
break;
case 5:
d.cancella();
d.insertscelta(nomeString);
break;
case 6:
d.cancella();
d.insertscelta(nomeString);
break;
case 7:
d.cancella();
d.insertscelta(nomeString);
break;
}
}
});
}
private void CursorLoader(Cursor c) {
// TODO Auto-generated method stub
}
}
我已经转换了我的代码：
public class SceltaDiete extends Fragment{
private static final String ARG_SECTION_NUMBER="section_number";
public SceltaDiete() {
// Required empty public constructor
}
ListView sceltadieta;
Database d;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.scelta_activity, container, false);
sceltadieta = (ListView) getActivity().findViewById(R.id.scelta_dieta);
d= new Database(getActivity());
final Cursor c = d.scelta();
CursorLoader(c);
String from[] = {Codice.DATI_ID,
Codice.DATI_NOME_DIETA};
int to[] = {R.id.record_id,
R.id.record_nome};
@SuppressWarnings("deprecation")
SimpleCursorAdapter sca = new SimpleCursorAdapter(getActivity(),
R.layout.singolo_elemento,
c, from, to);
sceltadieta = (ListView) getActivity().findViewById(R.id.scelta_dieta);
sceltadieta.setAdapter(sca);
sceltadieta.setClickable(true);
sceltadieta.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@SuppressWarnings("deprecation")
public void onItemClick(AdapterView<?> parent, View v, int position,
long id) {
TextView txtId = (TextView) v.findViewById(R.id.record_id);
TextView txtNome = (TextView) v.findViewById(R.id.record_nome);
String nomeString = (String) txtNome.getText();
String elemIdString = (String) txtId.getText();
final int elemIdInt = Integer.parseInt(elemIdString);
switch(elemIdInt){
case 1:
d.cancella();
d.insertscelta(nomeString);
break;
case 2:
d.cancella();
d.insertscelta(nomeString);
break;
case 3:
d.cancella();
d.insertscelta(nomeString);
break;
case 4:
d.cancella();
d.insertscelta(nomeString);
break;
case 5:
d.cancella();
d.insertscelta(nomeString);
break;
case 6:
d.cancella();
d.insertscelta(nomeString);
break;
case 7:
d.cancella();
d.insertscelta(nomeString);
break;
}
}
});
return rootView;
}
private void CursorLoader(Cursor c) {
// TODO Auto-generated method stub
}
@Override
public void onAttach(Activity activity){
super.onAttach(activity);
((MainActivity) activity).onSectionAttached(getArguments().getInt(
ARG_SECTION_NUMBER));
}
public static SceltaDiete newIstance(int sectionNumber){
SceltaDiete frag= new SceltaDiete();
Bundle args=new Bundle();
args.putInt(ARG_SECTION_NUMBER,sectionNumber);
frag.setArguments(args);
return frag;
}}
但是当我点击 Navigation Drawer 来显示我的 Fragment 时，应用程序崩溃了
这是 Logcat:
02-27 13:30:16.189: D/gralloc_goldfish(1095): Emulator without GPU emulation detected.
02-27 13:30:21.943: W/art(1095): Suspending all threads took: 8.538ms
02-27 13:30:22.053: I/art(1095): Background partial concurrent mark sweep GC freed 1886(118KB) AllocSpace objects, 0(0B) LOS objects, 52% free, 929KB/1953KB, paused 11.283ms total 410.100ms
02-27 13:30:23.025: I/Choreographer(1095): Skipped 117 frames! The application may be doing too much work on its main thread.
02-27 13:30:24.181: I/Choreographer(1095): Skipped 116 frames! The application may be doing too much work on its main thread.
02-27 13:30:27.901: I/Choreographer(1095): Skipped 188 frames! The application may be doing too much work on its main thread.
02-27 13:30:28.724: I/Choreographer(1095): Skipped 82 frames! The application may be doing too much work on its main thread.
02-27 13:30:29.371: I/Choreographer(1095): Skipped 65 frames! The application may be doing too much work on its main thread.
02-27 13:30:34.325: D/AndroidRuntime(1095): Shutting down VM
02-27 13:30:34.325: D/AndroidRuntime(1095): --------- beginning of crash
02-27 13:30:34.359: E/AndroidRuntime(1095): FATAL EXCEPTION: main
02-27 13:30:34.359: E/AndroidRuntime(1095): Process: com.lp.lemiediete, PID: 1095
02-27 13:30:34.359: E/AndroidRuntime(1095): java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference
02-27 13:30:34.359: E/AndroidRuntime(1095): at com.lp.lemiediete.SceltaDiete.onCreateView(SceltaDiete.java:48)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:947)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1126)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:739)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1489)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.FragmentManagerImpl.run(FragmentManager.java:454)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.os.Handler.handleCallback(Handler.java:739)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.os.Handler.dispatchMessage(Handler.java:95)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.os.Looper.loop(Looper.java:135)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.app.ActivityThread.main(ActivityThread.java:5221)
02-27 13:30:34.359: E/AndroidRuntime(1095): at java.lang.reflect.Method.invoke(Native Method)
02-27 13:30:34.359: E/AndroidRuntime(1095): at java.lang.reflect.Method.invoke(Method.java:372)
02-27 13:30:34.359: E/AndroidRuntime(1095): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
02-27 13:30:34.359: E/AndroidRuntime(1095): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
02-27 13:30:43.969: I/Process(1095): Sending signal. PID: 1095 SIG: 9
@Slaiv206 试试这个：
您必须做的改变：
public class SceltaDiete extends Fragment
代替ActionBarActivity
替换public void onCreate(Bundle savedInstanceState){
和
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
complete class:
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.SimpleCursorAdapter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;
public class SceltaDiete extends Fragment{
ListView sceltadieta;
Database d;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.scelta_activity, container, false);
sceltadieta = (ListView) findViewById(R.id.scelta_dieta);
d= new Database(getActivity());
final Cursor c = d.scelta();
CursorLoader(c);
String from[] = {Codice.DATI_ID,
Codice.DATI_NOME_DIETA};
int to[] = {R.id.record_id,
R.id.record_nome};
@SuppressWarnings("deprecation")
SimpleCursorAdapter sca = new SimpleCursorAdapter(this,
R.layout.singolo_elemento,
c, from, to);
sceltadieta = (ListView) findViewById(R.id.scelta_dieta);
sceltadieta.setAdapter(sca);
sceltadieta.setClickable(true);
sceltadieta.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@SuppressWarnings("deprecation")
public void onItemClick(AdapterView<?> parent, View v, int position,
long id) {
TextView txtId = (TextView) v.findViewById(R.id.record_id);
TextView txtNome = (TextView) v.findViewById(R.id.record_nome);
String nomeString = (String) txtNome.getText();
String elemIdString = (String) txtId.getText();
final int elemIdInt = Integer.parseInt(elemIdString);
switch(elemIdInt){
case 1:
d.cancella();
d.insertscelta(nomeString);
break;
case 2:
d.cancella();
d.insertscelta(nomeString);
break;
case 3:
d.cancella();
d.insertscelta(nomeString);
break;
case 4:
d.cancella();
d.insertscelta(nomeString);
break;
case 5:
d.cancella();
d.insertscelta(nomeString);
break;
case 6:
d.cancella();
d.insertscelta(nomeString);
break;
case 7:
d.cancella();
d.insertscelta(nomeString);
break;
}
}
});
return rootView;
}
private void CursorLoader(Cursor c) {
// TODO Auto-generated method stub
}
}
我正在尝试使用导航抽屉，我有一个包含 ListView 的 Activity 代码。我想将所有 Activity 转换为 Fragment，我该怎么做？
有人可以 post 我的代码转换成 Fragment 吗？
这是我的 activity 代码：
public class SceltaDiete extends ActionBarActivity{
ListView sceltadieta;
Database d = new Database(getApplicationContext());
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.scelta_activity);
sceltadieta = (ListView) findViewById(R.id.scelta_dieta);
final Cursor c = d.scelta();
CursorLoader(c);
String from[] = {Codice.DATI_ID,
Codice.DATI_NOME_DIETA};
int to[] = {R.id.record_id,
R.id.record_nome};
@SuppressWarnings("deprecation")
SimpleCursorAdapter sca = new SimpleCursorAdapter(this,
R.layout.singolo_elemento,
c, from, to);
sceltadieta = (ListView) findViewById(R.id.scelta_dieta);
sceltadieta.setAdapter(sca);
sceltadieta.setClickable(true);
sceltadieta.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@SuppressWarnings("deprecation")
public void onItemClick(AdapterView<?> parent, View v, int position,
long id) {
TextView txtId = (TextView) v.findViewById(R.id.record_id);
TextView txtNome = (TextView) v.findViewById(R.id.record_nome);
String nomeString = (String) txtNome.getText();
String elemIdString = (String) txtId.getText();
final int elemIdInt = Integer.parseInt(elemIdString);
switch(elemIdInt){
case 1:
d.cancella();
d.insertscelta(nomeString);
break;
case 2:
d.cancella();
d.insertscelta(nomeString);
break;
case 3:
d.cancella();
d.insertscelta(nomeString);
break;
case 4:
d.cancella();
d.insertscelta(nomeString);
break;
case 5:
d.cancella();
d.insertscelta(nomeString);
break;
case 6:
d.cancella();
d.insertscelta(nomeString);
break;
case 7:
d.cancella();
d.insertscelta(nomeString);
break;
}
}
});
}
private void CursorLoader(Cursor c) {
// TODO Auto-generated method stub
}
}
我已经转换了我的代码：
public class SceltaDiete extends Fragment{
private static final String ARG_SECTION_NUMBER="section_number";
public SceltaDiete() {
// Required empty public constructor
}
ListView sceltadieta;
Database d;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.scelta_activity, container, false);
sceltadieta = (ListView) getActivity().findViewById(R.id.scelta_dieta);
d= new Database(getActivity());
final Cursor c = d.scelta();
CursorLoader(c);
String from[] = {Codice.DATI_ID,
Codice.DATI_NOME_DIETA};
int to[] = {R.id.record_id,
R.id.record_nome};
@SuppressWarnings("deprecation")
SimpleCursorAdapter sca = new SimpleCursorAdapter(getActivity(),
R.layout.singolo_elemento,
c, from, to);
sceltadieta = (ListView) getActivity().findViewById(R.id.scelta_dieta);
sceltadieta.setAdapter(sca);
sceltadieta.setClickable(true);
sceltadieta.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@SuppressWarnings("deprecation")
public void onItemClick(AdapterView<?> parent, View v, int position,
long id) {
TextView txtId = (TextView) v.findViewById(R.id.record_id);
TextView txtNome = (TextView) v.findViewById(R.id.record_nome);
String nomeString = (String) txtNome.getText();
String elemIdString = (String) txtId.getText();
final int elemIdInt = Integer.parseInt(elemIdString);
switch(elemIdInt){
case 1:
d.cancella();
d.insertscelta(nomeString);
break;
case 2:
d.cancella();
d.insertscelta(nomeString);
break;
case 3:
d.cancella();
d.insertscelta(nomeString);
break;
case 4:
d.cancella();
d.insertscelta(nomeString);
break;
case 5:
d.cancella();
d.insertscelta(nomeString);
break;
case 6:
d.cancella();
d.insertscelta(nomeString);
break;
case 7:
d.cancella();
d.insertscelta(nomeString);
break;
}
}
});
return rootView;
}
private void CursorLoader(Cursor c) {
// TODO Auto-generated method stub
}
@Override
public void onAttach(Activity activity){
super.onAttach(activity);
((MainActivity) activity).onSectionAttached(getArguments().getInt(
ARG_SECTION_NUMBER));
}
public static SceltaDiete newIstance(int sectionNumber){
SceltaDiete frag= new SceltaDiete();
Bundle args=new Bundle();
args.putInt(ARG_SECTION_NUMBER,sectionNumber);
frag.setArguments(args);
return frag;
}}
但是当我点击 Navigation Drawer 来显示我的 Fragment 时，应用程序崩溃了 这是 Logcat:
02-27 13:30:16.189: D/gralloc_goldfish(1095): Emulator without GPU emulation detected.
02-27 13:30:21.943: W/art(1095): Suspending all threads took: 8.538ms
02-27 13:30:22.053: I/art(1095): Background partial concurrent mark sweep GC freed 1886(118KB) AllocSpace objects, 0(0B) LOS objects, 52% free, 929KB/1953KB, paused 11.283ms total 410.100ms
02-27 13:30:23.025: I/Choreographer(1095): Skipped 117 frames! The application may be doing too much work on its main thread.
02-27 13:30:24.181: I/Choreographer(1095): Skipped 116 frames! The application may be doing too much work on its main thread.
02-27 13:30:27.901: I/Choreographer(1095): Skipped 188 frames! The application may be doing too much work on its main thread.
02-27 13:30:28.724: I/Choreographer(1095): Skipped 82 frames! The application may be doing too much work on its main thread.
02-27 13:30:29.371: I/Choreographer(1095): Skipped 65 frames! The application may be doing too much work on its main thread.
02-27 13:30:34.325: D/AndroidRuntime(1095): Shutting down VM
02-27 13:30:34.325: D/AndroidRuntime(1095): --------- beginning of crash
02-27 13:30:34.359: E/AndroidRuntime(1095): FATAL EXCEPTION: main
02-27 13:30:34.359: E/AndroidRuntime(1095): Process: com.lp.lemiediete, PID: 1095
02-27 13:30:34.359: E/AndroidRuntime(1095): java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference
02-27 13:30:34.359: E/AndroidRuntime(1095): at com.lp.lemiediete.SceltaDiete.onCreateView(SceltaDiete.java:48)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:947)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1126)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:739)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1489)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.support.v4.app.FragmentManagerImpl.run(FragmentManager.java:454)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.os.Handler.handleCallback(Handler.java:739)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.os.Handler.dispatchMessage(Handler.java:95)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.os.Looper.loop(Looper.java:135)
02-27 13:30:34.359: E/AndroidRuntime(1095): at android.app.ActivityThread.main(ActivityThread.java:5221)
02-27 13:30:34.359: E/AndroidRuntime(1095): at java.lang.reflect.Method.invoke(Native Method)
02-27 13:30:34.359: E/AndroidRuntime(1095): at java.lang.reflect.Method.invoke(Method.java:372)
02-27 13:30:34.359: E/AndroidRuntime(1095): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
02-27 13:30:34.359: E/AndroidRuntime(1095): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
02-27 13:30:43.969: I/Process(1095): Sending signal. PID: 1095 SIG: 9
@Slaiv206 试试这个：
您必须做的改变：
public class SceltaDiete extends Fragment代替
ActionBarActivity替换
public void onCreate(Bundle savedInstanceState){和
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
complete class:
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.SimpleCursorAdapter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;
public class SceltaDiete extends Fragment{
ListView sceltadieta;
Database d;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.scelta_activity, container, false);
sceltadieta = (ListView) findViewById(R.id.scelta_dieta);
d= new Database(getActivity());
final Cursor c = d.scelta();
CursorLoader(c);
String from[] = {Codice.DATI_ID,
Codice.DATI_NOME_DIETA};
int to[] = {R.id.record_id,
R.id.record_nome};
@SuppressWarnings("deprecation")
SimpleCursorAdapter sca = new SimpleCursorAdapter(this,
R.layout.singolo_elemento,
c, from, to);
sceltadieta = (ListView) findViewById(R.id.scelta_dieta);
sceltadieta.setAdapter(sca);
sceltadieta.setClickable(true);
sceltadieta.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@SuppressWarnings("deprecation")
public void onItemClick(AdapterView<?> parent, View v, int position,
long id) {
TextView txtId = (TextView) v.findViewById(R.id.record_id);
TextView txtNome = (TextView) v.findViewById(R.id.record_nome);
String nomeString = (String) txtNome.getText();
String elemIdString = (String) txtId.getText();
final int elemIdInt = Integer.parseInt(elemIdString);
switch(elemIdInt){
case 1:
d.cancella();
d.insertscelta(nomeString);
break;
case 2:
d.cancella();
d.insertscelta(nomeString);
break;
case 3:
d.cancella();
d.insertscelta(nomeString);
break;
case 4:
d.cancella();
d.insertscelta(nomeString);
break;
case 5:
d.cancella();
d.insertscelta(nomeString);
break;
case 6:
d.cancella();
d.insertscelta(nomeString);
break;
case 7:
d.cancella();
d.insertscelta(nomeString);
break;
}
}
});
return rootView;
}
private void CursorLoader(Cursor c) {
// TODO Auto-generated method stub
}
}