我有一个应用程序从数据库中提取数据，并通过ListActivity和Cursor Loader将其放入listview。
代码如下：
public class PersonRecord extends ListActivity implements
LoaderManager.LoaderCallbacks<Cursor> {
private Uri addUri;
private TextView nameOfPerson, creditOfPerson;
private SimpleCursorAdapter adapter;
private String nameOfThePersonString;
// Used for menu deleting of a record
private static final int DELETE_ID = Menu.FIRST + 1;
// List for Listview
private ListView lv;
private static final String AUTHORITY = "com.fthatnoise.borrow.me.contentprovider";
// ---------------------------------------------------
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.person_record);
this.getListView().setDividerHeight(2);
init(); // Initialize parameters and GUI
// Gets the name of the person that was sent from the Borrower List
// class
Bundle extras = getIntent().getExtras();
// Toast.makeText(this, nameOfThePersonString, Toast.LENGTH_SHORT)
// .show();
if (extras != null) {
addUri = extras
.getParcelable(BorrowMeContentProvider.CONTENT_ITEM_TYPE);
// Try-catch when the records are finished, this prevents the program
// from crashing (Pulling 0 from database)
try{
fillData(addUri);
} catch (Exception e)
{
Toast.makeText(this, "There are no more records for this person", Toast.LENGTH_SHORT)
.show();
}
}
// Registers a content menu to the ListView
registerForContextMenu(getListView());
}
// ---------------------------------------------------
// Adding content menu to allow for the deletion of stored entries under peoples names
@Override public boolean onContextItemSelected(MenuItem item) {
switch (item.getItemId()) {
case (DELETE_ID):
// Gets the content for the assigned content menu - in this case the listview
AdapterContextMenuInfo info = (AdapterContextMenuInfo) item
.getMenuInfo();
// Find the entry for the item currently clicked on
Uri uri = Uri.parse(BorrowMeContentProvider.CONTENT_URI +
"/" + info.id);
getContentResolver().delete(uri, null, null);
// Reload the list with new data based on the name sent over
// from the person credit screen
/*
* Removed filldata for now, seems to work without it even though it crashes
* When removed it works fine but fails to refresh person record
* causes an error if all records are removed and person still shows up in
* the record screen.
*/
try {
} catch (Exception e){
Toast.makeText(this, "There are no more records for this person", Toast.LENGTH_SHORT)
.show();
}
return true;
}
return super.onContextItemSelected(item);
}
// ---------------------------------------------------
// Create Content Menu
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
// TODO Auto-generated method stub
super.onCreateContextMenu(menu, v, menuInfo);
//showDialog(DIALOG_SAB_PRIORITY_ID);
menu.add(0, DELETE_ID, 0, "Delete Record");
}
// ---------------------------------------------------
private void init() {
nameOfPerson = (TextView) findViewById(R.id.person_name);
creditOfPerson = (TextView) findViewById(R.id.person_credit);
}
// ---------------------------------------------------
// Loads record that was sent based on the ID
private void fillData(Uri uri) {
// Loads up the name of the person
String[] projection = { BorrowMeTable.COLUMN_NAME }; // Pulls only the
// name so far
Cursor databaseCursor = getContentResolver().query(uri, projection,
null, null, null);
if (databaseCursor != null) {
databaseCursor.moveToFirst();
nameOfThePersonString = databaseCursor.getString(databaseCursor
.getColumnIndexOrThrow(BorrowMeTable.COLUMN_NAME));
nameOfPerson.setText(nameOfThePersonString);
}
// Makes a raw query to the database in order to pull credit score for
// person being looked at.
ContentProviderClient client = getContentResolver()
.acquireContentProviderClient(AUTHORITY);
SQLiteDatabase dbHandle = ((BorrowMeContentProvider) client
.getLocalContentProvider()).getDbHandle();
Cursor cursor = dbHandle.rawQuery("SELECT sum("
+ BorrowMeTable.COLUMN_CREDIT_SCORE
+ ") AS creditcardtotal FROM " + BorrowMeTable.DATABASE_TABLE
+ " WHERE " + BorrowMeTable.COLUMN_NAME + "= \""
+ nameOfThePersonString + "\"", null);
cursor.moveToFirst();
int total = cursor.getInt(0);
cursor.close();
cursor.deactivate();
client.release(); // End of Credit Pull
// This is the formula to calc credit score.
// Everyone starts with 7, then it adds based on borrowed and returned items.
int defaultScore = 7;
int cnt = 0;
cnt = defaultScore + total;
// This is the start of the credit evaluation system.
// Based on what the final numbers are, this will assign them a credit score.
if (cnt >= 5 && cnt <= 6){
creditOfPerson.setText(cnt + " - Average");
creditOfPerson.setTypeface(null, Typeface.NORMAL);
}else if (cnt >= 7 && cnt <= 8){
creditOfPerson.setText(cnt + " - Good");
creditOfPerson.setTextColor(Color.MAGENTA);
creditOfPerson.setTypeface(null, Typeface.NORMAL);
}else if (cnt >= 2 && cnt <= 4){
creditOfPerson.setText(cnt + " - Bad");
creditOfPerson.setTextColor(Color.RED);
creditOfPerson.setTypeface(null, Typeface.NORMAL);
}else if (cnt >= 9){
creditOfPerson.setText(cnt + " - Fantastic");
creditOfPerson.setTextColor(Color.GREEN);
creditOfPerson.setTypeface(null, Typeface.NORMAL);
}else if (cnt <1){
// Stops showing the score if it drops below 1
creditOfPerson.setText("1 - Terrible");
creditOfPerson.setTextColor(Color.RED);
creditOfPerson.setTypeface(null, Typeface.BOLD);
}else if (cnt >= 10){
// Stops showing the score if it raises above 10
creditOfPerson.setText("10 - Wicked Awesome");
creditOfPerson.setTextColor(Color.GREEN);
creditOfPerson.setTypeface(null, Typeface.BOLD);
}
// End of credit score pull
// Loads the data for the rows of all items this person has borrowed
String[] from = new String[] { BorrowMeTable.COLUMN_ITEM,
BorrowMeTable.COLUMN_DATE, BorrowMeTable.COLUMN_BORROW_FLAG, BorrowMeTable.COLUMN_RETURN_DATE, BorrowMeTable.COLUMN_RETURN_FLAG, BorrowMeTable.COLUMN_IMAGE};
int[] to = new int[] { R.id.items_for_the_person_record,
R.id.borrowed_on_the_date, R.id.returned_on_the_date, R.id.returned_on_the_day, R.id.returned_cond, R.id.pic_of_item};
//getLoaderManager().initLoader(0, null, this); // This is where it was originally
adapter = new SimpleCursorAdapter(this, R.layout.rows_people_records,
null, from, to, 0);
// The viewbinder that allows the adapter to display BLOB images
adapter.setViewBinder(new MyViewBinder());
setListAdapter(adapter);
// Here is where I attempt to load the custom view binder to load the blob data
getLoaderManager().initLoader(0, null, this); // I have commented out above and placed it here
}
// ---------------------------------------------------
@Override
public Loader<Cursor> onCreateLoader(int arg0, Bundle arg1) {
String mSelection = BorrowMeTable.COLUMN_NAME + "=?"; // SQL request
String[] selectionArgs = { nameOfThePersonString }; // The actual
// argument
String[] projection = { BorrowMeTable.COLUMN_ID,
BorrowMeTable.COLUMN_ITEM, BorrowMeTable.COLUMN_DATE,
BorrowMeTable.COLUMN_BORROW_FLAG, BorrowMeTable.COLUMN_RETURN_DATE, BorrowMeTable.COLUMN_RETURN_FLAG, BorrowMeTable.COLUMN_IMAGE};
CursorLoader cursorLoader = new CursorLoader(this,
BorrowMeContentProvider.CONTENT_URI, projection, mSelection,
selectionArgs, null);
return cursorLoader;
}
// ---------------------------------------------------
@Override
public void onLoadFinished(Loader<Cursor> arg0, Cursor arg1) {
adapter.swapCursor(arg1);
}
// ---------------------------------------------------
@Override
public void onLoaderReset(Loader<Cursor> arg0) {
adapter.swapCursor(null);
}
}
我想知道是否可以轻松地重复使用相同的代码，如果我必须重做一堆。我已经查看了教程，但我没有看到任何完全回答我问题的内容。
答案 0 :(得分：0)
我建议您使用Activity替换然后更改一点