android - trying to create listview - android-activity

Question

i'm trying to write data from sqlite to a listview. the compiler doesn't show error, but when I run the app on my phone, it crashes. please help me
Cursor resultSet = db.rawQuery("Select * from weight_listview ORDER BY `id` DESC",null);
resultSet.moveToFirst();
String[] list = new String[] {};
String[] weighttolist={};
String[] datetolist={};
ArrayList<String> List=new ArrayList<String>();
ArrayList<String> List2=new ArrayList<String>();
resultSet.moveToFirst();
int x = 0;
while(resultSet.moveToNext()){
String data = resultSet.getString(resultSet.getColumnIndex("weight"));
String data2 = resultSet.getString(resultSet.getColumnIndex("date"));
String id = resultSet.getString(resultSet.getColumnIndex("ID"));
List.add(data + " " + data2);
x++;
}
final ListView listView = (ListView) findViewById(R.id.listView1);
if(List != null){
weighttolist=(String[])List.toArray(new String[0]);
String[] from = { "weight", "date" };
int[] to = { R.id.weight, R.id.date };
SimpleCursorAdapter cursorAdapter = new SimpleCursorAdapter(this,R.layout.row, resultSet, from, to);
listView.setAdapter(cursorAdapter);
// ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
// android.R.layout.simple_list_item_1, android.R.id.text1, weighttolist);
// ListView.setAdapter(adapter);
}
edit:
I successed to fix the problem but now I have another problem. I want that the listview will show 2 columns , not only 1 . I created fill row.xml , as you can see in the first code.
Cursor resultSet = db.rawQuery("Select * from weight_listview ORDER BY `id` DESC",null);
resultSet.moveToFirst();
String[] list = new String[] {};
String[] weighttolist={};
String[] datetolist={};
ArrayList<String> List=new ArrayList<String>();
ArrayList<String> List2=new ArrayList<String>();
resultSet.moveToFirst();
int x = 0;
while(resultSet.moveToNext()){
String data = resultSet.getString(resultSet.getColumnIndex("weight"));
String data2 = resultSet.getString(resultSet.getColumnIndex("date"));
List.add(data + " " + data2);
x++;
}
final ListView listView = (ListView) findViewById(R.id.listView1);
if(List != null){
weighttolist=(String[])List.toArray(new String[0]);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, android.R.id.text1, weighttolist);
listView.setAdapter(adapter);
}

Answer 1

Well without the exact error it is hard to see what is going wrong. Here is my guess you are using a SimpleAdapter who's constructor looks like this
SimpleAdapter(Context context, List<? extends Map<String, ?>> data, int resource, String[] from, int[] to)
For your second parameter you are using a Cursor not a list, your from variable are keys so you need to use a hash map I believe
Comment out your code and try this
List<HashMap<String, String>> List = new ArrayList<HashMap<String, String>>();
int x = 0;
while(resultSet.moveToNext()){
HashMap<String, String> map = new HashMap<String, String>();
String weight = resultSet.getString(resultSet.getColumnIndex("weight"));
String date = resultSet.getString(resultSet.getColumnIndex("date"));
String id = resultSet.getString(resultSet.getColumnIndex("ID"));
map.put("weight", weight);
map.put("date", date);
List.add(map);
x++;
}
final ListView listView = (ListView) findViewById(R.id.listView1);
if(List != null){
weighttolist=(String[])List.toArray(new String[0]);
String[] from = { "weight", "date" };
int[] to = { R.id.weight, R.id.date };
SimpleCursorAdapter cursorAdapter = new SimpleCursorAdapter(this,R.layout.row, List, from, to);
listView.setAdapter(cursorAdapter);