数据在文本框不保存

这是我的.h文件数据在文本框不保存

#import <UIKit/UIKit.h> 

// for use in xib/storyboard: 
#define TAG_TEXT_FIELD 10000 
#define CELL_REUSE_IDENTIFIER @"EditableTextCell" 

@interface EditableListViewController : UITableViewController 

// list data: 
@property (nonatomic, copy) NSArray *contents; 

// methods for possible overriding: 
- (void)contentsDidChange; 
- (UITextField *)createTextFieldForCell:(UITableViewCell *)cell; 

@end

，这是我的.m文件

#import "EditableListViewController.h" 

static NSString *inactiveTextFieldHint = @"Tap to add item"; 
static NSString *activeTextFieldHint = @""; 
static NSString *returnTappedTextFieldHint = @"~"; // HACK to mark when return was tapped 

#pragma mark - Helper Categories 

@interface UITextField (ChangeReturnKey) 
- (void)changeReturnKey:(UIReturnKeyType)returnKeyType; 
@end 

@implementation UITextField (ChangeReturnKey) 
- (void)changeReturnKey:(UIReturnKeyType)returnKeyType 
{ 
    self.returnKeyType = returnKeyType; 
    [self reloadInputViews]; 
} 
@end 

#pragma mark - EditableListViewController 

@interface EditableListViewController() <UITextFieldDelegate> { 
    NSMutableArray *rowsContent; 
} 
@end 

@implementation EditableListViewController 

#pragma mark - Contents Assignment 

- (NSArray *)contents 
{ 
    return rowsContent; 
} 

- (void)setContents:(NSArray *)contents 
{ 
    rowsContent = [NSMutableArray arrayWithArray:contents]; 
    [self.tableView reloadData]; 
} 

#pragma mark - Table Changes 

- (void)deleteRow:(NSIndexPath *)indexPath 
{ 
    [rowsContent removeObjectAtIndex:indexPath.row]; 
    [self.tableView beginUpdates]; 
    [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationAutomatic]; 
    [self.tableView endUpdates]; 
    [self contentsDidChange]; 
} 

- (void)addRow:(NSIndexPath *)indexPath text:(NSString *)text 
{ 
    if (rowsContent == nil) { 
     rowsContent = [[NSMutableArray alloc] initWithCapacity:1]; 
    } 
    [rowsContent addObject:text]; 
    NSIndexPath *nextRow = [NSIndexPath indexPathForRow:indexPath.row+1 inSection:indexPath.section]; 
    [self.tableView beginUpdates]; 
    [self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationAutomatic]; 
    [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:nextRow] withRowAnimation:UITableViewRowAnimationAutomatic]; 
    [self.tableView endUpdates]; 
    [self contentsDidChange]; 
} 

- (void)contentsDidChange 
{ 
} 

#pragma mark - Table View Data Source 

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView 
{ 
    return 1; 
} 

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{ 
    return rowsContent.count + 1; // extra one for inserting new row 
} 

- (UITextField *)createTextFieldForCell:(UITableViewCell *)cell 
{ 
    CGFloat padding = 8.0f; 
    CGRect frame = CGRectInset(cell.contentView.bounds, padding, padding/2); 
    UITextField *textField = [[UITextField alloc] initWithFrame:frame]; 
    CGFloat spareHeight = cell.contentView.bounds.size.height - textField.font.pointSize; 
    frame.origin.y = self.tableView.style == UITableViewStyleGrouped ? spareHeight/2 : spareHeight - padding/2; 
    textField.frame = frame; 
    textField.tag = TAG_TEXT_FIELD; 
    textField.borderStyle = UITextBorderStyleNone; 
    textField.returnKeyType = UIReturnKeyDone; 
    textField.autocapitalizationType = UITextAutocapitalizationTypeSentences; 
    textField.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleTopMargin; 
    return textField; 
} 

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{ 
    static NSString *reuseIdentifier = CELL_REUSE_IDENTIFIER; 
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifier]; 
    if (cell == nil) { 
     cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:reuseIdentifier]; 
    } 

    UITextField *textField = (UITextField *)[cell viewWithTag:TAG_TEXT_FIELD]; 
    if (textField == nil) { 
     textField = [self createTextFieldForCell:cell]; 
     [cell.contentView addSubview:textField]; 
    } 
    textField.delegate = self; 
    if (indexPath.row < rowsContent.count) { 
     textField.text = [rowsContent objectAtIndex:indexPath.row]; 
     textField.placeholder = nil; 
    } else { 
     textField.text = nil; 
     textField.placeholder = NSLocalizedString(inactiveTextFieldHint, nil); 
    } 

    return cell; 
} 

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath 
{ 
    switch (editingStyle) { 

     case UITableViewCellEditingStyleDelete: { 
      [self deleteRow:indexPath]; 
      break; 
     } 

     case UITableViewCellEditingStyleInsert: { 
      UITableViewCell *sourceCell = [tableView cellForRowAtIndexPath:indexPath]; 
      UIView *textField = [sourceCell viewWithTag:TAG_TEXT_FIELD]; 
      [textField becomeFirstResponder]; 
      break; 
     } 

     case UITableViewCellEditingStyleNone: 
      break; 
    } 
} 

- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath 
{ 
    return (indexPath.section == 0); 
} 

- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath 
{ 
    return indexPath.section == 0 && indexPath.row < rowsContent.count; 
} 

- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath 
{ 
    NSString *rowContent = [rowsContent objectAtIndex:fromIndexPath.row]; 
    [rowsContent removeObjectAtIndex:fromIndexPath.row]; 
    [rowsContent insertObject:rowContent atIndex:toIndexPath.row]; 
    [self contentsDidChange]; 
} 

#pragma mark - Table View Delegate 

- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath 
{ 
    if (indexPath.section != 0) return UITableViewCellEditingStyleNone; 
    return indexPath.row < rowsContent.count ? UITableViewCellEditingStyleDelete : UITableViewCellEditingStyleInsert; 
} 

- (NSIndexPath *)tableView:(UITableView *)tableView 
    targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath 
    toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath 
{ 
    return proposedDestinationIndexPath.section == 0 && proposedDestinationIndexPath.row < rowsContent.count 
     ? proposedDestinationIndexPath 
     : [NSIndexPath indexPathForRow:rowsContent.count-1 inSection:0]; 
} 

#pragma mark - UITextFieldDelegate 

- (NSIndexPath *)cellIndexPathForField:(UITextField *)textField 
{ 
    UITableViewCell *parentCell = (UITableViewCell *)[[textField superview] superview]; 
    return [self.tableView indexPathForCell:parentCell]; 
} 

- (NSUInteger)rowIndexForField:(UITextField *)textField 
{ 
    return [self cellIndexPathForField:textField].row; 
} 

- (void)textFieldDidBeginEditing:(UITextField *)textField 
{ 
    if ([textField.text length] == 0) { 
     textField.placeholder = NSLocalizedString(activeTextFieldHint, nil); 
    } 
} 

- (BOOL)textFieldShouldReturn:(UITextField *)textField 
{ 
    textField.placeholder = returnTappedTextFieldHint; 
    [textField resignFirstResponder]; 
    return YES; 
} 

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string 
{ 
    if (textField.text.length == 0) { 
     // if it's the last field, change the return key to "Next" 
     if ([self rowIndexForField:textField] == rowsContent.count) { 
      [textField changeReturnKey:UIReturnKeyNext]; 
     } 
    } 
    else { 
     // if return button is "Next" and field is about to be empty, change to "Done" 
     if (textField.returnKeyType == UIReturnKeyNext && string.length == 0 && range.length == textField.text.length) { 
      [textField changeReturnKey:UIReturnKeyDone]; 
     } 
    } 

    return YES; 
} 

- (BOOL)textFieldShouldClear:(UITextField *)textField 
{ 
    if (textField.returnKeyType == UIReturnKeyNext) { 
     [textField changeReturnKey:UIReturnKeyDone]; 
    } 

    return YES; 
} 

- (void)textFieldDidEndEditing:(UITextField *)textField 
{ 
    NSIndexPath *currRow = [self cellIndexPathForField:textField]; 
    NSUInteger cellIndex = currRow.row; 
    if (cellIndex < rowsContent.count) { 
     if ([textField.text length]) { 
      if (![textField.text isEqualToString:[rowsContent objectAtIndex:cellIndex]]) { 
       [rowsContent replaceObjectAtIndex:cellIndex withObject:textField.text]; 
       [self contentsDidChange]; 
      } 
     } 
     else { 
      [self deleteRow:currRow]; 
     } 
    } 
    else { // new row 
     if ([textField.text length]) { 
      [self addRow:currRow text:textField.text]; 
      [textField changeReturnKey:UIReturnKeyDone]; 
      if ([textField.placeholder isEqual:returnTappedTextFieldHint]) { // if tapped return, go to the next field 
       UITableViewCell *nextCell = [self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:cellIndex+1 inSection:currRow.section]]; 
       UIView *nextTextField = [nextCell viewWithTag:TAG_TEXT_FIELD]; 
       [nextTextField becomeFirstResponder]; 
      } 
     } 
     else { 
      textField.placeholder = NSLocalizedString(inactiveTextFieldHint, nil); 
     } 
    } 
} 

#pragma mark - View lifecycle 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    self.navigationItem.rightBarButtonItem = self.editButtonItem; 
} 

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation 
{ 
    // Return YES for supported orientations 
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); 
} 

@end

当一些用户类型，并离开该应用程序，退出程序在多任务处理中，用户放入的文本消失并将文本重置为喜欢它的文本是在开始时。

我该怎么做，以便用户放入的文本能够保存。

请帮助我！

来源

2013-03-09 user2102538

保存在文本NSUserDefaults的时候用户完成编辑。然后下一次运行显示从NSUserDefaults获取的initialText。 – 2013-03-09 05:28:36

我使用哪些代码来使用NSUserDefaults – user2102538 2013-03-12 19:44:31

@ user2102538正如您所问，这是使用NSUserDefaults的方式。

Saving 

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults]; 

// saving an NSString 
[prefs setObject:@"TextToSave" forKey:@"keyToLookupString"]; 

// saving an NSInteger 
[prefs setInteger:42 forKey:@"integerKey"]; 

// saving a Double 
[prefs setDouble:3.1415 forKey:@"doubleKey"]; 

// saving a Float 
[prefs setFloat:1.2345678 forKey:@"floatKey"]; 

// This is suggested to synch prefs. 


[prefs synchronize];///////Very Important. This SAVES THE NEWLY ADDED INTO NSUserDefaults 


Retrieving 

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults]; 

// getting an NSString 
NSString *myString = [prefs stringForKey:@"keyToLookupString"]; 

// getting an NSInteger 
NSInteger myInt = [prefs integerForKey:@"integerKey"]; 

// getting an Float 
float myFloat = [prefs floatForKey:@"floatKey"];

可以检查NSUserDefault是否有对象与

[[NSUserDefaults standardUserDefaults] boolForKey:@"yourKey"] // returns bool

，甚至可以使用这样

if(![[NSUserDefaults standardUserDefaults] objectForKey:@"yourKey"]) 
{ 
//no object present. Set the object. 
} 
else 
{ 
//retrieve the object and do what u wish 
}

来源

2013-03-13 15:54:22

数据在文本框不保存

回答

相关问题