先生，如果我在 android 模拟器中按下后退按钮，如何刷新我的列表视图？我在activityA 上单击了一个项目，然后转到activityB 中的编辑表单。保存更新后，如果我按下后退按钮，它应该刷新列表。
这是我的活动A
public class CustomListView extends Activity {
final Context context = this;
public static String name;
public static String number;
int REQUEST_CODE = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
GroupDb info = new GroupDb(this);
info.open();
ArrayList<Contact> searchResults = info.getView();
MyCustomBaseAdapter mcba = new MyCustomBaseAdapter(CustomListView.this, searchResults);
mcba.updateResults(searchResults);
final ListView lv = (ListView) findViewById(R.id.srListView);
lv.setAdapter(new MyCustomBaseAdapter(this, searchResults));
info.close();
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> a, View v, int position, long id) {
// TODO Auto-generated method stub
Object o = lv.getItemAtPosition(position);
final Contact fullObject = (Contact)o;
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(context);
alertDialogBuilder
.setMessage("Select action")
.setCancelable(false)
.setPositiveButton("Edit", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
Toast.makeText(getApplicationContext(), "Edit ", Toast.LENGTH_LONG).show();
name = fullObject.getName();
number = fullObject.getPhoneNumber();
Intent intent = new Intent();
intent.setClass(CustomListView.this, EditDetails.class);
startActivityForResult(intent, REQUEST_CODE);
}
})
.setNeutralButton("Delete", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
Toast.makeText(getApplicationContext(), "Delete ", Toast.LENGTH_LONG).show();
}
})
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// if this button is clicked, just close
// the dialog box and do nothing
dialog.cancel();
}
});
// create alert dialog
AlertDialog alertDialog = alertDialogBuilder.create();
// show it
alertDialog.show();
}
});
}
public void onResume()
{ // After a pause OR at startup
super.onResume();
//Refresh your stuff here
GroupDb info = new GroupDb(this);
info.open();
ArrayList<Contact> searchResults = info.getView();
MyCustomBaseAdapter mcba = new MyCustomBaseAdapter(CustomListView.this, searchResults);
mcba.updateResults(searchResults);
info.close();
}
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
super.onActivityResult(requestCode, resultCode, intent);
if (requestCode == REQUEST_CODE) {
GroupDb info = new GroupDb(this);
info.open();
ArrayList<Contact> searchResults = info.getView();
MyCustomBaseAdapter mcba = new MyCustomBaseAdapter(CustomListView.this, searchResults);
mcba.updateResults(searchResults);
info.close();
}
}
//edit or delete list when clicked
public void deleteEditOption()
{
}//end deleteEditOption()
}
这是我的活动B
public class EditDetails extends Activity{
public String nameChanged;
public String numChanged;
public String name;
public String num;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.editdetails);
final EditText sqlName = (EditText)findViewById(R.id.editName);
final EditText sqlNumber = (EditText)findViewById(R.id.editNumber);
name = CustomListView.name;
num = CustomListView.number;
Button bUpdate = (Button)findViewById(R.id.editUpdate);
Button bView = (Button)findViewById(R.id.editView);
sqlName.setText(name);
sqlNumber.setText(num);
bUpdate.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
nameChanged = sqlName.getText().toString();
numChanged = sqlNumber.getText().toString();
GroupDb info = new GroupDb(EditDetails.this);
info.open();
long rowid = info.getRowId(name, num);
info.updateNameNumber(rowid+1, nameChanged, numChanged);
Toast.makeText(getApplicationContext(), rowid+" "+nameChanged+" "+numChanged, Toast.LENGTH_LONG).show();
ArrayList<Contact> searchResults = info.getView();
MyCustomBaseAdapter mcba = new MyCustomBaseAdapter(EditDetails.this, searchResults);
mcba.updateResults(searchResults);
Toast.makeText(getApplicationContext(), "Update Successful!", Toast.LENGTH_LONG).show();
info.close();
}
});
bView.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
Intent intent = new Intent();
intent.setClass(EditDetails.this, CustomListView.class);
startActivityForResult(intent, 0);
}
});
}
}
如果我在我的活动 B 中单击此 bView 按钮，它会更新列表视图。但按下后退按钮只会显示我之前未更新的列表视图。提前感谢您的帮助
编辑
public class MyCustomBaseAdapter extends BaseAdapter {
private static ArrayList<Contact> searchArrayList;
private LayoutInflater mInflater;
public MyCustomBaseAdapter(Context context, ArrayList<Contact> results) {
searchArrayList = results;
mInflater = LayoutInflater.from(context);
}
public void updateResults(ArrayList<Contact> results) {
searchArrayList = results;
//Triggers the list update
notifyDataSetChanged();
}
public int getCount() {
return searchArrayList.size();
}
public Object getItem(int position) {
return searchArrayList.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.custom_row_view, null);
holder = new ViewHolder();
holder.txtName = (TextView) convertView.findViewById(R.id.name);
holder.txtPhone = (TextView) convertView.findViewById(R.id.phone);
holder.status = (TextView) convertView.findViewById(R.id.status);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.txtName.setText(searchArrayList.get(position).getName());
holder.txtPhone.setText(searchArrayList.get(position).getPhoneNumber());
holder.status.setText(searchArrayList.get(position).getStatus());
return convertView;
}
static class ViewHolder {
TextView txtName;
TextView txtPhone;
TextView status;
}
}