我第一次运行程序时，正在调用所有覆盖的UITableView方法。但是如果我在模拟器中终止应用程序并从模拟器主屏幕重新启动，则不会调用某些被覆盖的方法（例如commitEditingStyle），而是调用预设方法。
有没有理由说他们在重新启动应用后不会被调用，但是在明确运行后会有效？
我的表格代码：
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// set toolbar delegate for editing toolbar style
self.aToolbar.delegate = self;
numberOfSections = 1; // for editing: initial number of sections
// for testing
NSLog(@"%@", ptrBookmarks1);
// load bookmarks segment bar with user's most recent segment selections
bookmarksSegmentControl.selectedSegmentIndex = selectedBookmarksSegmentIndex;
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
self.navigationItem.rightBarButtonItem = self.editButtonItem;
//allow row selection during editing.
//if the "Add New Song" row is selected we can trigger an insert.
//rather than forcing the using to click the (+) icon directly
self.aTableView.allowsSelectionDuringEditing = YES;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
// selected table data
NSMutableArray *tableData;
switch (bookmarksSegmentControl.selectedSegmentIndex) {
case 0: // Bookmarks 1 selected
tableData = ptrBookmarks1;
break;
case 1: // Bookmarks 2 selected
tableData = ptrBookmarks2;
break;
case 2: // My Songs selected
tableData = ptrMySongs;
break;
}
if ([self isEditing]) // the current view is in editing mode, return count + an extra row
return [tableData count] + 1;
else // return count
return [tableData count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];
if(cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"cell"];
}
// selected table data
NSMutableArray *tableData;
switch (bookmarksSegmentControl.selectedSegmentIndex) {
case 0: // Bookmarks 1 selected
tableData = ptrBookmarks1;
break;
case 1: // Bookmarks 2 selected
tableData = ptrBookmarks2;
break;
case 2: // My Songs selected
tableData = ptrMySongs;
break;
}
//if number of rows is greater than the total number of rows in the data set
//and this view is in editing mode.
//Initialize the cell for "Add New Song"
//there will be an extra row once SetEditing: is called
if(indexPath.row >= tableData.count && [self isEditing]){
cell.textLabel.text = @"Add New Song";
//cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; // display arrow accessory
}
else {
cell.textLabel.text = [tableData objectAtIndex:indexPath.row];
//cell.accessoryType = UITableViewCellAccessoryNone; // hide arrow accessory
}
return cell;
}
//VIEW CONTROLLER METHOD: IMPORTANT
//this is a method of the view controller
//if we use apple's editing button as follows:
//self.navigationItem.rightBarButtonItem = self.editButtonItem
//then this method will be called automatically for us.
//if we are using a button callback or similar method,
//then we need to call setEditing: manually on the view
-(void) setEditing:(BOOL)editing animated:(BOOL)animated{
//wrap our code in an if statement
//only run the code if we are not swipe deleting a row.
//if we were called due to a swipeDelete action, ignore it
if(isSwipeDeleting == NO){
//call parent
[aTableView setEditing:editing];
[super setEditing:editing animated:animated];
// selected table data
NSMutableArray *tableData;
switch (bookmarksSegmentControl.selectedSegmentIndex) {
case 0: // Bookmarks 1 selected
tableData = ptrBookmarks1;
break;
case 1: // Bookmarks 2 selected
tableData = ptrBookmarks2;
break;
case 2: // My Songs selected
tableData = ptrMySongs;
break;
}
//if editing mode
if(editing){
//batch the table view changes so that everything happens at once
[self.aTableView beginUpdates];
//for each section, insert a row at the end of the table
for(int i = 0; i < numberOfSections; i++){
//create an index path for the new row
NSIndexPath *path = [NSIndexPath indexPathForRow:tableData.count inSection:i];
//insert the NSIndexPath to create a new row. NOTE: this method takes an array of paths
[self.aTableView insertRowsAtIndexPaths:@[path] withRowAnimation:UITableViewRowAnimationAutomatic];
}
//animate the changes now
[self.aTableView endUpdates];
}else{
//batch the table view changes so that everything happens at once
[self.aTableView beginUpdates];
//for each section, insert a row at the end of the table
for(int i = 0; i < numberOfSections; i++){
//create an index path for the new row
NSIndexPath *path = [NSIndexPath indexPathForRow:tableData.count inSection:i];
//insert the NSIndexPath to create a new row. NOTE: this method takes an array of paths
[self.aTableView deleteRowsAtIndexPaths:@[path] withRowAnimation:UITableViewRowAnimationAutomatic];
}
//animate the changes now
[self.aTableView endUpdates];
}
}
}
//DELEGATE METHOD:
//this method will be called for every row and allows us to set the
//editing syle icon(Delete,Insert)
-(UITableViewCellEditingStyle) tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath{
// selected table data
NSMutableArray *tableData;
switch (bookmarksSegmentControl.selectedSegmentIndex) {
case 0: // Bookmarks 1 selected
tableData = ptrBookmarks1;
break;
case 1: // Bookmarks 2 selected
tableData = ptrBookmarks2;
break;
case 2: // My Songs selected
tableData = ptrMySongs;
break;
}
// Detemine if it's in editing mode
if (self.editing) {
//use the + icon(add icon) on row
//if this is the additional row created in setEditing:animated:
if(indexPath.row >= tableData.count){
return UITableViewCellEditingStyleInsert;
}
else {
//use the delete icon on this row
return UITableViewCellEditingStyleDelete;
}
}
else
return UITableViewCellEditingStyleNone;
}
//handle the deletion/insertion
//this method is called when the delete or insert icon has been press.
//we should update our dataSource by inserting or removing the selected INDEX
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
// selected table data
NSMutableArray *tableData;
switch (bookmarksSegmentControl.selectedSegmentIndex) {
case 0: // Bookmarks 1 selected
tableData = ptrBookmarks1;
break;
case 1: // Bookmarks 2 selected
tableData = ptrBookmarks2;
break;
case 2: // My Songs selected
tableData = ptrMySongs;
break;
}
if (editingStyle == UITableViewCellEditingStyleDelete) { // the delete icon was clicked
// delete pre-test
NSLog(@"Array before delete: %@", tableData);
NSLog(@"Directory before delete: ");
[self readDirectoryContents];
// if deleting a song or its pages that's in view, switch view to previous MySong if exists, otherwise About page/a blank page
////////insert code here////////
// remove file and its annotations from directory (if deleting from My Songs)
if (tableData == ptrMySongs) {
[self deleteImportedSongsheet:tableData[indexPath.row]];
}
//remove row from tableData
[tableData removeObjectAtIndex:indexPath.row];
//remove the row in the tableView
[self.aTableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
// delete post-test
NSLog(@"Array after delete: %@", tableData);
NSLog(@"Directory after delete: ");
[self readDirectoryContents];
[self.aTableView reloadData];
}
else if (editingStyle == UITableViewCellEditingStyleInsert) { // the insert icon was clicked
/*
//add a new row to the datasource
[tableData addObject:@"New Icon"];
//insert a row in the tableView because the plusIcon was clicked.
[self.aTableView insertRowsAtIndexPaths:@[indexPath]
withRowAnimation:UITableViewRowAnimationAutomatic];*/
self.editing = false; // turn off editing
// ---SEGUE TO SONG IMPORT OPTIONS TABLE---
SongImportView *songImportView =
[[SongImportView alloc]
initWithNibName:@"SongImportView" bundle:nil];
// forward the My Songs array
songImportView.ptrMySongs = ptrMySongs;
// set delegate
songImportView.delegate = self;
// push SongImportView
[self.navigationController pushViewController:songImportView animated:YES];
[SongImportView release];
}
}
//if we are in editing mode we do not want to perform Seque Transition
- (BOOL)shouldPerformSegueWithIdentifier:(NSString *)identifier sender:(id)sender {
if ([identifier isEqualToString:@"MyDetailView"] && [self isEditing]) {
return NO;
}
return YES;
}
//this method is called when the user swipes to delete a row.
- (void)tableView:(UITableView *)tableView willBeginEditingRowAtIndexPath:(NSIndexPath *)indexPath{
isSwipeDeleting = YES;//user just swipe to delete a row
}
//when the user cancel the swipe or click the delete button
//this method is call
- (void)tableView:(UITableView *)tableView didEndEditingRowAtIndexPath:(NSIndexPath *)indexPath{
isSwipeDeleting = NO;//swipe to delete ended. No longer showing the DELETE button in cell
}
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {
// Return NO if you do not want the item to be re-orderable.
return NO;
//return YES;
}
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath {
// MUST CHANGE canMoveRowAtIndexPath TO ENABLE THIS
NSString *item;
// selected table data
NSMutableArray *tableData;
switch (bookmarksSegmentControl.selectedSegmentIndex) {
case 0: // Bookmarks 1 selected
tableData = ptrBookmarks1;
break;
case 1: // Bookmarks 2 selected
tableData = ptrBookmarks2;
break;
case 2: // My Songs selected
tableData = ptrMySongs;
break;
}
item = [[tableData objectAtIndex:fromIndexPath.row] retain];
[tableData removeObjectAtIndex:fromIndexPath.row];
[tableData insertObject:item atIndex:toIndexPath.row];
[item release];
}
#pragma mark - Table view delegate
//DELEGATE METHOD:
//the user selected a row
//In order for the user to perform an INSERTION action on a row,
//they have to click the + icon icon. We can implement this method
//so that they can click anywhere on the "Add New Song" to add a new row
//tableView.allowsSelectionDuringEditing = YES; must be set
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
//deselect the selected row with animatiion
[self.aTableView deselectRowAtIndexPath:indexPath animated:YES];
// selected table data
NSMutableArray *tableData;
switch (bookmarksSegmentControl.selectedSegmentIndex) {
case 0: // Bookmarks 1 selected
tableData = ptrBookmarks1;
break;
case 1: // Bookmarks 2 selected
tableData = ptrBookmarks2;
break;
case 2: // My Songs selected
tableData = ptrMySongs;
break;
}
//if the selected row was the "Add New Song" row call tableView:commitEditingStyle:
//to add a new row
if (indexPath.row >= tableData.count && [self isEditing]) {
[self tableView:tableView commitEditingStyle:UITableViewCellEditingStyleInsert forRowAtIndexPath:indexPath];
}
else { // otherwise do regular table item selection
[self.delegate didTapBookmarksTable:[tableData objectAtIndex:indexPath.row]];
}
}
// to scroll the table to the top row that was last viewed
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:YES];
NSIndexPath *iP;
switch (bookmarksSegmentControl.selectedSegmentIndex) {
case 0: // Bookmarks 1 selected
if ([ptrBookmarks1 count] > 0) { // make sure that there is something in the table before scrolling to it, otherwise will crash
iP = [NSIndexPath indexPathForRow:bookmark1listPositionRow inSection:bookmark1listPositionSection];
[aTableView scrollToRowAtIndexPath:iP atScrollPosition:UITableViewScrollPositionTop animated:NO];
}
break;
case 1: // Bookmarks 2 selected
if ([ptrBookmarks2 count] > 0) { // make sure that there is something in the table before scrolling to it, otherwise will crash
iP = [NSIndexPath indexPathForRow:bookmark2listPositionRow inSection:bookmark2listPositionSection];
[aTableView scrollToRowAtIndexPath:iP atScrollPosition:UITableViewScrollPositionTop animated:NO];
}
break;
case 2: // My Songs selected
if ([ptrMySongs count] > 0) { // make sure that there is something in the table before scrolling to it, otherwise will crash
iP = [NSIndexPath indexPathForRow:mysongslistPositionRow inSection:mysongslistPositionSection];
[aTableView scrollToRowAtIndexPath:iP atScrollPosition:UITableViewScrollPositionTop animated:NO];
}
break;
}
}
// remember the top row that was last viewed
- (void)viewDidDisappear:(BOOL)animated {
NSIndexPath *ip;
switch (bookmarksSegmentControl.selectedSegmentIndex) {
case 0: // Bookmarks 1 selected
if ([ptrBookmarks1 count] > 0) { // make sure that there is something in the table before scrolling to it, otherwise will crash
ip = [[aTableView indexPathsForVisibleRows] objectAtIndex:0];
bookmark1listPositionSection = ip.section;
bookmark1listPositionRow = ip.row;
}
break;
case 1: // Bookmarks 2 selected
if ([ptrBookmarks2 count] > 0) { // make sure that there is something in the table before scrolling to it, otherwise will crash
ip = [[aTableView indexPathsForVisibleRows] objectAtIndex:0];
bookmark2listPositionSection = ip.section;
bookmark2listPositionRow = ip.row;
}
break;
case 2: // My Songs selected
if ([ptrMySongs count] > 0) { // make sure that there is something in the table before scrolling to it, otherwise will crash
ip = [[aTableView indexPathsForVisibleRows] objectAtIndex:0];
mysongslistPositionSection = ip.section;
mysongslistPositionRow = ip.row;
}
break;
}
}