我似乎在将对象列表实现为简单的 ListView 时遇到了麻烦。
这是每个列表元素的对象类。包 com.example.android.fragments;
package com.example.android.fragments;
public class ListObject {
public String objectname; //name of schedule
public boolean[] Days = {
false, //monday
false, //tuesday
false, //and soforth
false,
false,
false,
false};
public int starthour, startminute, stophour, stopminute; //times from TimePicker
public boolean vibrate;
public ListObject()
{
objectname = null; //if doesnt work, do objectname = "";
vibrate = false;
starthour = 8;
startminute = 0;
stophour = 15;
stopminute = 0;
}
public ListObject(String name, boolean[] newdays, boolean vib, int a, int b, int c, int d)
{
objectname = name;
Days = newdays;
vibrate = vib;
starthour = a;
startminute = b;
stophour = c;
stopminute = d;
}
@Override
public String toString()
{
String startampm = "am";
String stopampm = "am";
if (starthour > 11) //turns into am/pm
{
startampm = "pm";
starthour -= 12;
}
if (stophour > 11) //turns into am/pm
{
stopampm = "pm";
stophour -= 12;
}
String daysstring = null ; //initializes string representing days activated
for(int i = 0; i < 7; i++) //add into string the correct days
{
if (Days[i] == true)
{
if(i == 0)
daysstring += "M, ";
else if (i == 1)
daysstring += "Tu, ";
else if (i == 2)
daysstring += "W, ";
else if (i == 3)
daysstring += "Th, ";
else if (i == 4)
daysstring += "F, ";
else if (i == 5)
daysstring += "Sa, ";
else
daysstring += "Su, ";
}
}
daysstring = daysstring.substring(0, daysstring.length() - 3); //removes the last ', '
daysstring += ": ";
String timestring =
starthour + ":" + startminute + " " + startampm + " - " +
stophour + ":" + stopminute + " " + stopampm;
return objectname + "\n" + daysstring + timestring;
}
}
我的主要活动将布局设置为 mainlayout，这是一个 FrameLayout
package com.example.android.fragments;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
public class MainActivity extends FragmentActivity
implements MainListFragment.OnListSelectedListener {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mainlayout);
// Check whether the activity is using the layout version with
// the fragment_container FrameLayout. If so, we must add the first fragment
if (findViewById(R.id.fragment_container) != null) { //meaning, if using phone version
// However, if we're being restored from a previous state,
// then we don't need to do anything and should return or else
// we could end up with overlapping fragments.
if (savedInstanceState != null) {
return;
}
// Create an instance of ExampleFragment
MainListFragment firstFragment = new MainListFragment();
// In case this activity was started with special instructions from an Intent,
// pass the Intent's extras to the fragment as arguments
firstFragment.setArguments(getIntent().getExtras());
// Add the fragment to the 'fragment_container' FrameLayout
getSupportFragmentManager().beginTransaction()
.add(R.id.fragment_container, firstFragment).commit();
}
}
public void onArticleSelected(int position) {
// Capture the article fragment from the activity layout
InfoFragment articleFrag = (InfoFragment)
getSupportFragmentManager().findFragmentById(R.id.article_fragment); //article_fragment exists in layout-large
if (articleFrag != null) {
// If article frag is available, we're in two-pane layout...
// Call a method in the ArticleFragment to update its content
articleFrag.updateArticleView(position);
} else {
// phone layout - swap frags
// Create fragment and give it an argument for the selected article
InfoFragment newFragment = new InfoFragment();
Bundle args = new Bundle();
args.putInt(InfoFragment.ARG_POSITION, position);
newFragment.setArguments(args);
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack so the user can navigate back
transaction.replace(R.id.fragment_container, newFragment);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
}
}
}
这就是问题所在，在我应该在应用程序启动时打开的 ListFragment 中，我不能简单地创建 3 个对象并将它们放在我的 listlayout.xml 中定义的 listview 中，它的 ListView id 为主列表视图
package com.example.android.fragments;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.app.ListActivity;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class MainListFragment extends ListFragment{ //used to extend ListActivity{
OnListSelectedListener mCallback;
// The container Activity must implement this interface so the frag can deliver messages
public interface OnListSelectedListener {
/** Called by ListFragment when a list item is selected */
public void onArticleSelected(int position);
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// We need to use a different list item layout for devices older than Honeycomb
int layout = Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ?
android.R.layout.simple_list_item_activated_1 : android.R.layout.simple_list_item_1;
//using this now to add properties
ListView mainlist = (ListView)getView().findViewById(R.id.mainlistview);
//INFO FOR MADE UP OBJECTS
boolean[] Days1 = {
true, //monday
false, //tuesday
true, //and soforth
false,
true,
false,
false};
boolean[] Days2 = {
false, //monday
false, //tuesday
false, //and soforth
false,
true,
true,
true};
boolean[] Days3 = {
false, //monday
false, //tuesday
false, //and soforth
true,
false,
false,
false};
//create sample objects
ListObject[] scheduleobjs =
{
new ListObject("Club Practice", Days1, true, 1, 0, 5, 25),
new ListObject("Work", Days2, true, 3, 30, 14, 20),
new ListObject("Church", Days3, true, 12, 5, 14, 20)
};
// String[] liststring =
// {
// scheduleobjs[0].toString(),
// scheduleobjs[1].toString(),
// scheduleobjs[2].toString()
// };
// ArrayList<ListObject> arraylist; //add objects to arraylist
// arraylist.add(scheduleobjs[0]);
// arraylist.add(scheduleobjs[1]);
// arraylist.add(scheduleobjs[2]);
String[] arraylist = new String[]
{
scheduleobjs[0].toString(),
scheduleobjs[1].toString(),
scheduleobjs[2].toString()
};
ArrayAdapter<String> arrayadapter = new ArrayAdapter<String>(this, layout, arraylist);
// setListAdapter(new ArrayAdapter<String>(getActivity(), layout, ))
mainlist.setAdapter(arrayadapter);
//inflate here???
}
@Override
public void onStart() {
super.onStart();
// When in two-pane layout, set the listview to highlight the selected list item
// (We do this during onStart because at the point the listview is available.)
// if (getFragmentManager().findFragmentById(R.id.article_fragment) != null) {
// getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE); COMMENTED OUT BECAUSE USED IN 2 PANE LAYOUT
// }
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
// This makes sure that the container activity has implemented
// the callback interface. If not, it throws an exception.
try {
mCallback = (OnListSelectedListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnListSelectedListener");
}
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
// Notify the parent activity of selected item
mCallback.onArticleSelected(position);
// Set the item as checked to be highlighted when in two-pane layout
getListView().setItemChecked(position, true);
}
}
您可以看到我已经注释掉了以前使用对象类的覆盖 toString() 执行此操作的尝试，我哪里出错了，实现它的最佳方法是什么？我想最终创建一个更好的列表视图，因为它只显示一个字符串，并且我想要不同大小和颜色的文本，每个对象都有一个复选框，但现在我只是想让它工作。