UITextField secureTextEntry bullets with a custom

问题:

I’m using a custom font in a UITextField, which has secureTextEntry turned on. When I’m typing in the cell, I see the bullets in my chosen font, but when the field loses focus, those bullets revert to the system standard font. If I tap the field again, they change back to my font, and so on.

Is there a way I can ensure that they continue to display the custom font’s bullets, even when the field is out of focus?

回答1:

A subclass that works this issue around. Create an arbitrary UITextField, then set the secure property to YES (via KVC in IB).

Actually it implements a comment suggested by lukech. When textfield ends editing, it switches to an arbitrary textfield, then set a bulk of dots into, and some hack in text accessor to always get the actual text the field holds.

@interface SecureTextFieldWithCustomFont : UITextField
@property (nonatomic) BOOL secure;
@property (nonatomic, strong) NSString *actualText;
@end


@implementation SecureTextFieldWithCustomFont


-(void)awakeFromNib
{
    [super awakeFromNib];

    if (self.secureTextEntry)
    {
        // Listen for changes.
        [self addTarget:self action:@selector(editingDidBegin) forControlEvents:UIControlEventEditingDidBegin];
        [self addTarget:self action:@selector(editingDidChange) forControlEvents:UIControlEventEditingChanged];
        [self addTarget:self action:@selector(editingDidFinish) forControlEvents:UIControlEventEditingDidEnd];
    }
}

-(NSString*)text
{
    if (self.editing || self.secure == NO)
    { return [super text]; }

    else
    { return self.actualText; }
}

-(void)editingDidBegin
{
    self.secureTextEntry = YES;
    self.text = self.actualText;
}

-(void)editingDidChange
{ self.actualText = self.text; }

-(void)editingDidFinish
{
    self.secureTextEntry = NO;
    self.actualText = self.text;
    self.text = [self dotPlaceholder];
}

-(NSString*)dotPlaceholder
{
    int index = 0;
    NSMutableString *dots = @"".mutableCopy;
    while (index < self.text.length)
    { [dots appendString:@"•"]; index++; }
    return dots;
}


@end

May be augmented to work with non NIB instantiations, handling default values, etc, but you probably get the idea.

回答2:

For those having trouble with losing custom fonts when toggling secureTextEntry, I found a work-around (I'm using the iOS 8.4 SDK). I was trying to make a toggle for showing/hiding a password in a UITextField. Every time I'd toggle secureTextEntry = NO my custom font got borked, and only the last character showed the correct font. Something funky is definitely going on with this, but here's my solution:

-(void)showPassword {
    [self.textField resignFirstResponder];
    self.textField.secureTextEntry = NO;
}

First responder needs to be resigned for some reason. You don't seem to need to resign the first responder when setting secureTextEntry to YES, only when setting to NO.

回答3:

The actual problem appears to be that the editing view (UITextField does not draw its own text while editing) uses bullets (U+2022) to draw redacted characters, while UITextField uses black circles (U+25CF). I suppose that in the default fonts, these characters look the same.

Here's an alternate workaround for anyone interested, which uses a custom text field subclass, but doesn't require juggling the text property or other special configuration. IMO, this keeps things relatively clean.

@interface MyTextField : UITextField
@end

@implementation MyTextField

- (void)drawTextInRect:(CGRect)rect
{
    if (self.isSecureTextEntry)
    {
        NSMutableParagraphStyle *paragraphStyle = [NSMutableParagraphStyle new];
        paragraphStyle.alignment = self.textAlignment;

        NSMutableDictionary *attributes = [NSMutableDictionary dictionary];
        [attributes setValue:self.font forKey:NSFontAttributeName];
        [attributes setValue:self.textColor forKey:NSForegroundColorAttributeName];
        [attributes setValue:paragraphStyle forKey:NSParagraphStyleAttributeName];

        CGSize textSize = [self.text sizeWithAttributes:attributes];

        rect = CGRectInset(rect, 0, (CGRectGetHeight(rect) - textSize.height) * 0.5);
        rect.origin.y = floorf(rect.origin.y);

        NSMutableString *redactedText = [NSMutableString new];
        while (redactedText.length < self.text.length)
        {
            [redactedText appendString:@"\u2022"];
        }

        [redactedText drawInRect:rect withAttributes:attributes];
    }
    else
    {
        [super drawTextInRect:rect];
    }
}

@end

回答4:

While this is an iOS bug (and new in iOS 7, I should add), I do have another way to work around it that one might find acceptable. The functionality is still slightly degraded but not by much.

Basically, the idea is to set the font to the default font family/style whenever the field has something entered in it; but when nothing is entered, set it to your custom font. (The font size can be left alone, as it's the family/style, not the size, that is buggy.) Trap every change of the field's value and set the font accordingly at that time. Then the faint "hint" text when nothing is entered has the font that you want (custom); but when anything is entered (whether you are editing or not) will use default (Helvetica). Since bullets are bullets, this should look fine.

The one downside is that the characters, as you type before being replaced by bullets, will use default font (Helvetica). That's only for a split second per character though. If that is acceptable, then this solution works.

回答5:

I found a trick for this issue.

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
   if ([textField tag]== TAG_PASS || [textField tag]== TAG_CPASS)
    {
       // To fix password dot size
        if ([[textField text] isEqualToString:@"" ])
        {
          [textField setText:@" "];
          [textField resignFirstResponder];
          [textField becomeFirstResponder];
          [textField setText:@""];
        }  
    }
}

回答6:

[passWordTextField resignFirstResponder];
passWordTextField.secureTextEntry = !passWordTextField.secureTextEntry;
[passWordTextField becomeFirstResponder];

This is the fastest way to solve this bug！

回答7:

iOS is acting a bit strange when it comes to custom fonts. Try removing "Adjust to Fit" for that textfield. If that doesn't work, I'm guessing that what bothering you is the size increase of the font.

A simple solution for that would be:

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    if(textField.secureTextEntry)
    {
        [textField setFont:[UIFont fontWithName:@"Helvetica-Bold" size:10.0]];
    }
}

-(void)textFieldDidEndEditing:(UITextField *)textField
{
    if(textField.secureTextEntry)
    {
        [textField setFont:[UIFont fontWithName:@"Helvetica-Bold" size:10.0]];
    }
}

You'll need to play with the size a bit in order for it to look like there is no size change when loosing focus on the UITextField.

If you have a major spacing problem between characters like in the edited question, the simplest (and a bit ugly) solution would be to create a Bullet image that matches the above size & spacing and matches the amount of characters entered by the user that will appear when the user leaves the UITextField.

回答8:

A secureTextEntry text field can be avoided altogether:

NSString *pin = @"";
BOOL pasting = FALSE;
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    if(!pasting) {
        pin = [pin stringByReplacingCharactersInRange:range withString:string];

        // Bail out when deleting a character
        if([string length] == 0) {
            return YES;
        }

        pasting = TRUE;
        [textField paste:@"●"];

        return NO;
    } else {
        pasting = FALSE;
        return YES;
    }
}

回答9:

I recommend to resignFirstResponder before you change scureTextEntry and then becomeFirstResponder again as it is posted here: https://stackoverflow.com/a/34777286/1151916