Obj-c/Cocoa touch：有UITableViewCell - CellTextField只接受數字字符？

Question

我想有一個UITableViewCell中的CellTextField只接受數字字符。 我編程方式創建UITableViewCells這樣的：

-(UITableViewCell*) getCellContentView: (NSString*) cellIdentifier { 

     ... 

     UITableViewCell *cell = [[UITableViewCell alloc] initWithFrame:cellFrame reuseIdentifier:cellIdentifier]; 

     ... 

     CellTextField *txt; 
     txt = [[CellTextField alloc] initWithFrame:amountFrame]; 

     ... //here we should setup a delegate or similar to handle char validation for txt 

     [cell.contentView addSubview:txt]; 
     return cell; 
    } 

因爲我們有一個委託「shouldChangeCharactersInRange」的UITextField組件，但我找不到CellTextFields相當。

Answer 1

試試這個

.H

@interface YourClass : ParentClass <UITextFieldDelegate>{ 
    NSNumberFormatter *integerNumberFormatter; 
    } 
    @end 

.M

-(void)viewDidLoad 
{ 
     [integerNumberFormatter setMaximumFractionDigits:0]; 
     yourTextField.delegate = self; 
} 

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string { 

    NSString* proposedString = [textField.text stringByReplacingCharactersInRange:range withString:string]; 
    NSNumber *proposedNumber = [integerNumberFormatter numberFromString:proposedString]; 
    if (proposedNumber) { 
     NSString *integerString = [integerNumberFormatter stringFromNumber:proposedNumber]; 
     if ([integerString isEqualToString:proposedString]) { 
      // proposed string is an integer 
      return YES; 
     } 
    } 

    return NO; 
}