我有两个项目,我已经完成了一个课程。一个是简单的待办事项列表,另一个允许使用不同的片段,具体取决于您是处于纵向还是横向模式。两者都有效,但是当我试图将两者结合起来时,如果我扩展Fragment(findByViews和setContentView不起作用),我在片段中放入To Do活动会出错。
我可以用FragmentActivity替换Fragment来解决这个问题,然后修复我的MainActivity.java的fragmentTransaction.replace(android.R.id.content,pm_fragment);得到一个错误说: " FragmentTransaction中的replace(int,android.app.Fragment)无法应用于(int,com.android.MyFragmentsTodo.PM_Fragment)"
有谁能告诉我我能做些什么来使这项工作?我明天有一个测试,我担心讲师可能会要求我们将活动与碎片混合在一起。 任何帮助将不胜感激。
MainActivity.java
package com.android.myfragmentstodo;
import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.content.res.Configuration;
import android.support.v4.app.FragmentActivity;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends ActionBarActivity{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Configuration config = getResources().getConfiguration();
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
//check device orientation and act upon it
if(config.orientation == Configuration.ORIENTATION_LANDSCAPE){
// If orientation is landscape then
LM_Fragment ls_fragment = new LM_Fragment();
fragmentTransaction.replace(android.R.id.content, ls_fragment);
}else{
// If orientation is portrait then
PM_Fragment pm_fragment = new PM_Fragment();
fragmentTransaction.replace(android.R.id.content, pm_fragment);
}
//apply (commit) the changes
fragmentTransaction.commit();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
PM_Fragment.java
package com.android.myfragmentstodo;
import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
/**
* Created by Malan on 4/20/2015.
*/
public class PM_Fragment extends android.support.v4.app.Fragment {
private ArrayList<String> items;
private ArrayAdapter<String> adapter;
private ListView listView;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedinstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.todoItems);
items = new ArrayList<String>();
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, items);
listView.setAdapter(adapter);
Button button = (Button) findViewById(R.id.btnAddItem);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
EditText editText = (EditText) findViewById(R.id.todoEdit);
String itemText = editText.getText().toString();
adapter.add(itemText);
editText.setText("");
Toast toast = Toast.makeText(getApplicationContext(), "Item Added", Toast.LENGTH_SHORT);
toast.show();
}
});
setupListViewListener();
return inflater.inflate(R.layout.lm_fragment, container, false);
}
private void setupListViewListener() {
listView.setOnItemLongClickListener(
new AdapterView.OnItemLongClickListener(){
@Override
public boolean onItemLongClick(AdapterView<?> av,
View item, int pos, long id){
items.remove(pos);
adapter.notifyDataSetChanged();
return true;
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void AddItem(View view) {
EditText editText = (EditText) findViewById(R.id.todoEdit);
String itemText = editText.getText().toString();
adapter.add(itemText);
editText.setText("");
}
}
答案 0 :(得分:1)
好的,我已经找到了解决问题的方法。必须继续扩展Fragment但是在使用findViewById时必须使用:
rootView = inflater.inflate(R.layout.pm_fragment, container, false);
然后在所有findViewById之前使用rootView,如下所示:
listView = (ListView) rootView.findViewById(R.id.todoItems);
每当使用“this”时,请使用“getActivity()”,例如:
adapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, items);
使用getApplicationContext时,必须使用getActivity()。getApplicationContext(),例如:
Toast toast = Toast.makeText(getActivity().getApplicationContext(), "Item Added", Toast.LENGTH_SHORT);
最后我的PM_Fragment被改为看起来像这样: PM_Fragment.java
package com.android.myfragmentstodo;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
/**
* Created by Malan on 4/20/2015.
*/
public class PM_Fragment extends Fragment {
private ArrayList<String> items;
private ArrayAdapter<String> adapter;
private ListView listView;
View rootView;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedinstanceState){
rootView = inflater.inflate(R.layout.pm_fragment, container, false);
listView = (ListView) rootView.findViewById(R.id.todoItems);
items = new ArrayList<String>();
adapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, items);
listView.setAdapter(adapter);
Button button = (Button) rootView.findViewById(R.id.btnAddItem);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
EditText editText = (EditText) rootView.findViewById(R.id.todoEdit);
String itemText = editText.getText().toString();
adapter.add(itemText);
editText.setText("");
Toast toast = Toast.makeText(getActivity().getApplicationContext(), "Item Added", Toast.LENGTH_SHORT);
toast.show();
}
});
setupListViewListener();
return rootView;
}
private void setupListViewListener() {
listView.setOnItemLongClickListener(
new AdapterView.OnItemLongClickListener(){
@Override
public boolean onItemLongClick(AdapterView<?> av,
View item, int pos, long id){
items.remove(pos);
adapter.notifyDataSetChanged();
return true;
}
});
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void AddItem(View view) {
EditText editText = (EditText) rootView.findViewById(R.id.todoEdit);
String itemText = editText.getText().toString();
adapter.add(itemText);
editText.setText("");
}
}