iPhone UITextField - 更改占位符文本颜色

Question

我想更改我在UITextField控件中设置的占位符文本的颜色,使其变黑.

我更喜欢这样做而不使用普通文本作为占位符,并且必须覆盖所有方法来模仿占位符的行为.

我相信如果我重写这个方法:

- (void)drawPlaceholderInRect:(CGRect)rect

然后我应该能够做到这一点.但我不确定如何从此方法中访问实际的占位符对象.

Answer 1

自从在iOS 6中的UIViews中引入属性字符串以来,可以为占位符文本指定颜色,如下所示:

if ([textField respondsToSelector:@selector(setAttributedPlaceholder:)]) {
  UIColor *color = [UIColor blackColor];
  textField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:placeholderText attributes:@{NSForegroundColorAttributeName: color}];
} else {
  NSLog(@"Cannot set placeholder text's color, because deployment target is earlier than iOS 6.0");
  // TODO: Add fall-back code to set placeholder color.
}

Answer 2

容易和无痛,可能是一些容易的替代品.

_placeholderLabel.textColor

不建议生产,Apple可能会拒绝您的提交.

Answer 3

您可以这样覆盖drawPlaceholderInRect:(CGRect)rect以手动呈现占位符文本:

- (void) drawPlaceholderInRect:(CGRect)rect {
    [[UIColor blueColor] setFill];
    [[self placeholder] drawInRect:rect withFont:[UIFont systemFontOfSize:16]];
}

Answer 4

您可以使用以下代码将占位符文本颜色更改为您想要的任何颜色.

UIColor *color = [UIColor lightTextColor];
YOURTEXTFIELD.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"PlaceHolder Text" attributes:@{NSForegroundColorAttributeName: color}];

Answer 5

也许您想尝试这种方式,但Apple可能会警告您访问私有ivar:

[self.myTextField setValue:[UIColor darkGrayColor] 
                forKeyPath:@"_placeholderLabel.textColor"];

注:
根据MartinAlléus的说法,这不再适用于iOS 7.

Answer 6

这适用于Swift <3.0:

myTextField.attributedPlaceholder = 
NSAttributedString(string: "placeholder text", attributes: [NSForegroundColorAttributeName : UIColor.redColor()])

在iOS 8.2和iOS 8.3 beta 4中测试过.

斯威夫特3:

myTextfield.attributedPlaceholder =
NSAttributedString(string: "placeholder text", attributes: [NSForegroundColorAttributeName : UIColor.red])

斯威夫特4:

myTextfield.attributedPlaceholder =
NSAttributedString(string: "placeholder text", attributes: [NSAttributedStringKey.foregroundColor: UIColor.red])

Swift 4.2:

myTextfield.attributedPlaceholder =
NSAttributedString(string: "placeholder text", attributes: [NSAttributedString.Key.foregroundColor: UIColor.red])

Answer 7

在Swift中:

if let placeholder = yourTextField.placeholder {
    yourTextField.attributedPlaceholder = NSAttributedString(string:placeholder, 
        attributes: [NSForegroundColorAttributeName: UIColor.blackColor()])
}

在Swift 4.0中:

if let placeholder = yourTextField.placeholder {
    yourTextField.attributedPlaceholder = NSAttributedString(string:placeholder, 
        attributes: [NSAttributedStringKey.foregroundColor: UIColor.black])
}

Answer 8

Swift 3.0 +故事板

要在故事板中更改占位符颜色,请使用下一个代码创建扩展名.(随意更新此代码,如果您认为,它可以更清晰,更安全).

extension UITextField {
    @IBInspectable var placeholderColor: UIColor {
        get {
            guard let currentAttributedPlaceholderColor = attributedPlaceholder?.attribute(NSForegroundColorAttributeName, at: 0, effectiveRange: nil) as? UIColor else { return UIColor.clear }
            return currentAttributedPlaceholderColor
        }
        set {
            guard let currentAttributedString = attributedPlaceholder else { return }
            let attributes = [NSForegroundColorAttributeName : newValue]

            attributedPlaceholder = NSAttributedString(string: currentAttributedString.string, attributes: attributes)
        }
    }
}

Swift 4版

extension UITextField {
    @IBInspectable var placeholderColor: UIColor {
        get {
            return attributedPlaceholder?.attribute(.foregroundColor, at: 0, effectiveRange: nil) as? UIColor ?? .clear
        }
        set {
            guard let attributedPlaceholder = attributedPlaceholder else { return }
            let attributes: [NSAttributedStringKey: UIColor] = [.foregroundColor: newValue]
            self.attributedPlaceholder = NSAttributedString(string: attributedPlaceholder.string, attributes: attributes)
        }
    }
}

Answer 9

以下仅适用于iOS6 +(如Alexander W的评论中所示):

UIColor *color = [UIColor grayColor];
nameText.attributedPlaceholder =
   [[NSAttributedString alloc]
       initWithString:@"Full Name"
       attributes:@{NSForegroundColorAttributeName:color}];

Answer 10

有了这个,我们可以在iOS中更改textfield的占位符文本的颜色

[self.userNameTxt setValue:[UIColor colorWithRed:41.0/255.0 green:91.0/255.0 blue:106.0/255.0 alpha:1.0] forKeyPath:@"_placeholderLabel.textColor"];

Answer 11

我已经遇到过这个问题.在我的情况下,代码是正确的.

目标C.

[textField setValue:[UIColor whiteColor] forKeyPath:@"_placeholderLabel.textColor"];

对于Swift 4.X

tf_mobile.setValue(UIColor.white, forKeyPath: "_placeholderLabel.textColor")

希望,这可能会对你有所帮助.

Answer 12

你为什么不用UIAppearance方法:

[[UILabel appearanceWhenContainedIn:[UITextField class], nil] setTextColor:[UIColor whateverColorYouNeed]];

Answer 13

同样在你的故事板中,没有单行代码

Answer 14

适用于iOS 6.0 +

[textfield setValue:your_color forKeyPath:@"_placeholderLabel.textColor"];

希望能帮助到你.

注意: Apple可能会拒绝(0.01%几率)您的应用,因为我们正在访问私有API.我在两年后的所有项目中都使用了这个,但Apple没有要求这个.

Answer 15

对于Xamarin.iOS开发人员,我在本文档中找到了它 https://developer.xamarin.com/api/type/Foundation.NSAttributedString/

textField.AttributedPlaceholder = new NSAttributedString ("Hello, world",new UIStringAttributes () { ForegroundColor =  UIColor.Red });

Answer 16

Swift版本.可能它会帮助某人.

class TextField: UITextField {
   override var placeholder: String? {
        didSet {
            let placeholderString = NSAttributedString(string: placeholder!, attributes: [NSForegroundColorAttributeName: UIColor.whiteColor()])
            self.attributedPlaceholder = placeholderString
        }
    }
}

Answer 17

迅速3.X

textField.attributedPlaceholder = NSAttributedString(string: "placeholder text", attributes:[NSForegroundColorAttributeName: UIColor.black])

迅速5

textField.attributedPlaceholder = NSAttributedString(string: "placeholder text", attributes: [NSAttributedString.Key.foregroundColor : UIColor.black])

Answer 18

这个 Swift 4.1 的解决方案

    textName.attributedPlaceholder = NSAttributedString(string: textName.placeholder!, attributes: [NSAttributedStringKey.foregroundColor : UIColor.red])

Answer 19

iOS 6或更高版本提供attributedPlaceholder的UITextField.的iOS 3.2和更高版本提供setAttributes:range:的NSMutableAttributedString.

您可以执行以下操作:

NSMutableAttributedString *ms = [[NSMutableAttributedString alloc] initWithString:self.yourInput.placeholder];
UIFont *placeholderFont = self.yourInput.font;
NSRange fullRange = NSMakeRange(0, ms.length);
NSDictionary *newProps = @{NSForegroundColorAttributeName:[UIColor yourColor], NSFontAttributeName:placeholderFont};
[ms setAttributes:newProps range:fullRange];
self.yourInput.attributedPlaceholder = ms;

Answer 20

在iOS7中处理垂直和水平对齐以及占位符的颜色.drawInRect和drawAtPoint不再使用当前上下文fillColor.

https://developer.apple.com/library/ios/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/CustomTextProcessing/CustomTextProcessing.html

OBJ-C

@interface CustomPlaceHolderTextColorTextField : UITextField

@end


@implementation CustomPlaceHolderTextColorTextField : UITextField


-(void) drawPlaceholderInRect:(CGRect)rect  {
    if (self.placeholder) {
        // color of placeholder text
        UIColor *placeHolderTextColor = [UIColor redColor];

        CGSize drawSize = [self.placeholder sizeWithAttributes:[NSDictionary dictionaryWithObject:self.font forKey:NSFontAttributeName]];
        CGRect drawRect = rect;

        // verticially align text
        drawRect.origin.y = (rect.size.height - drawSize.height) * 0.5;

        // set alignment
        NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
        paragraphStyle.alignment = self.textAlignment;

        // dictionary of attributes, font, paragraphstyle, and color
        NSDictionary *drawAttributes = @{NSFontAttributeName: self.font,
                                     NSParagraphStyleAttributeName : paragraphStyle,
                                     NSForegroundColorAttributeName : placeHolderTextColor};


        // draw
        [self.placeholder drawInRect:drawRect withAttributes:drawAttributes];
    }
}

@end

Answer 21

类别FTW.可以进行优化以检查有效的颜色变化.

#import <UIKit/UIKit.h>

@interface UITextField (OPConvenience)

@property (strong, nonatomic) UIColor* placeholderColor;

@end

#import "UITextField+OPConvenience.h"

@implementation UITextField (OPConvenience)

- (void) setPlaceholderColor: (UIColor*) color {
    if (color) {
        NSMutableAttributedString* attrString = [self.attributedPlaceholder mutableCopy];
        [attrString setAttributes: @{NSForegroundColorAttributeName: color} range: NSMakeRange(0,  attrString.length)];
        self.attributedPlaceholder =  attrString;
    }
}

- (UIColor*) placeholderColor {
    return [self.attributedPlaceholder attribute: NSForegroundColorAttributeName atIndex: 0 effectiveRange: NULL];
}

@end

Answer 22

带有警告的斯威夫特 5。

let attributes = [ NSAttributedString.Key.foregroundColor: UIColor.someColor ]
let placeHolderString = NSAttributedString(string: "DON'T_DELETE", attributes: attributes)
txtField.attributedPlaceholder = placeHolderString

需要注意的是，您必须String在“DON'T_DELETE”所在的位置输入非空，即使该字符串是在其他地方的代码中设置的。可能会为您节省五分钟的头疼时间。