iPhone UITextField-更改占位符文本颜色

我想更改在UITextField控件中设置的占位符文本的颜色，使其变黑。

我更愿意在不使用常规文本作为占位符的情况下执行此操作，而必须重写所有方法来模仿占位符的行为。

我相信如果我重写此方法：

- (void)drawPlaceholderInRect:(CGRect)rect

那么我应该能够做到这一点。但是我不确定如何从此方法中访问实际的占位符对象。

由于iOS 6的UIViews中引入了属性字符串，因此可以为占位符文本分配颜色，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.
}

简单且无痛苦，对于某些人来说可能是一个简单的选择。

_placeholderLabel.textColor

不建议生产，Apple可能会拒绝您的提交。

您可以这样重写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]];
}

您可以使用以下代码将占位符文本颜色更改为所需的任何颜色。

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

也许您想尝试这种方式，但是Apple可能会警告您有关访问私有ivar的信息：

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

注意
根据MartinAlléus的说法，这在iOS 7上不再有效。

在Swift <3.0中可以使用：

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

在iOS 8.2和iOS 8.3 beta 4中进行了测试。

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])

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])
}

Swift 3.0 +故事板

为了在情节提要中更改占位符颜色，请使用下一个代码创建扩展。（如果您认为可以随意更新此代码，则可以更清楚，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版本

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)
        }
    }
}

Swift 5版本

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: [NSAttributedString.Key: UIColor] = [.foregroundColor: newValue]
            self.attributedPlaceholder = NSAttributedString(string: attributedPlaceholder.string, attributes: attributes)
        }
    }
}

以下仅适用于iOS6 +（如Alexander W的评论所示）：

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

我已经遇到了这个问题。就我而言，以下代码是正确的。

目标C

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

对于Swift 4.X

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

对于iOS 13 Swift代码

tf_mobile.attributedPlaceholder = NSAttributedString(string:"PlaceHolder Text", attributes: [NSAttributedString.Key.foregroundColor: UIColor.red])

您还可以针对iOS 13使用以下代码

let iVar = class_getInstanceVariable(UITextField.self, "_placeholderLabel")!
let placeholderLabel = object_getIvar(tf_mobile, iVar) as! UILabel
placeholderLabel.textColor = .red

希望对您有帮助。

这样我们就可以在iOS中更改文本字段占位符文本的颜色

[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"];

你为什么不只使用UIAppearance方法：

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

同样在情节提要中，无需单行代码

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])

对于iOS 6.0 +

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

希望能帮助到你。

注意： 由于我们正在访问私有API，Apple可能会拒绝（0.01％的机会）您的应用程序。自两年以来，我在所有项目中都使用了此功能，但Apple并没有要求这样做。

对于Xamarin.iOS开发人员，我可以从本文档中找到它 https://developer.xamarin.com/api/type/Foundation.NSAttributedString/

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

迅捷版。可能会帮助某人。

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

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

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

对象

@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

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;

Swift 4.1的此解决方案

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

重写drawPlaceholderInRect:是正确的方法，但是由于API（或文档）中的错误，它无法正常工作。

该方法永远不会在上调用UITextField。

另请参见UITextField上的drawTextInRect未调用

您可以使用digdog的解决方案。由于我不确定是否能通过苹果的审查，因此我选择了另一种解决方案：用我自己的标签覆盖文本字段，以模仿占位符行为。

不过这有点混乱。代码看起来像这样（注意，我正在TextField的子类中执行此操作）：

@implementation PlaceholderChangingTextField

- (void) changePlaceholderColor:(UIColor*)color
{    
    // Need to place the overlay placeholder exactly above the original placeholder
    UILabel *overlayPlaceholderLabel = [[[UILabel alloc] initWithFrame:CGRectMake(self.frame.origin.x + 8, self.frame.origin.y + 4, self.frame.size.width - 16, self.frame.size.height - 8)] autorelease];
    overlayPlaceholderLabel.backgroundColor = [UIColor whiteColor];
    overlayPlaceholderLabel.opaque = YES;
    overlayPlaceholderLabel.text = self.placeholder;
    overlayPlaceholderLabel.textColor = color;
    overlayPlaceholderLabel.font = self.font;
    // Need to add it to the superview, as otherwise we cannot overlay the buildin text label.
    [self.superview addSubview:overlayPlaceholderLabel];
    self.placeholder = nil;
}

我是Xcode的新手，我找到了一种实现相同效果的方法。

我将uilabel放置在所需格式的占位符上，并将其隐藏在

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    switch (textField.tag)
    {
        case 0:
            lblUserName.hidden=YES;
            break;

        case 1:
            lblPassword.hidden=YES;
            break;

        default:
            break;
    }
}

我同意它是可以解决的，而不是真正的解决方案，但是从此链接获得的效果是相同的

注意：在iOS 7上仍然可以使用：

带CAVEAT的Swift 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String是，即使在其他地方的代码中设置了该字符串，也必须在“ DON'T_DELETE”所在的位置输入非空值。可能会节省您五分钟的时间。

对于iOS7及以下版本，我能做的最好的事情是：

- (CGRect)placeholderRectForBounds:(CGRect)bounds {
  return [self textRectForBounds:bounds];
}

- (CGRect)editingRectForBounds:(CGRect)bounds {
  return [self textRectForBounds:bounds];
}

- (CGRect)textRectForBounds:(CGRect)bounds {
  CGRect rect = CGRectInset(bounds, 0, 6); //TODO: can be improved by comparing font size versus bounds.size.height
  return rect;
}

- (void)drawPlaceholderInRect:(CGRect)rect {
  UIColor *color =RGBColor(65, 65, 65);
  if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
    [self.placeholder drawInRect:rect withAttributes:@{NSFontAttributeName:self.font, UITextAttributeTextColor:color}];
  } else {
    [color setFill];
    [self.placeholder drawInRect:rect withFont:self.font];
  }
}

对于使用Monotouch（Xamarin.iOS）的用户，以下是亚当的答案，已翻译为C＃：

public class MyTextBox : UITextField
{
    public override void DrawPlaceholder(RectangleF rect)
    {
        UIColor.FromWhiteAlpha(0.5f, 1f).SetFill();
        new NSString(this.Placeholder).DrawString(rect, Font);
    }
}

我需要保持占位符对齐，因此亚当的答案对我来说还不够。

为了解决这个问题，我使用了一个小的变体，希望对您有所帮助：

- (void) drawPlaceholderInRect:(CGRect)rect {
    //search field placeholder color
    UIColor* color = [UIColor whiteColor];

    [color setFill];
    [self.placeholder drawInRect:rect withFont:self.font lineBreakMode:UILineBreakModeTailTruncation alignment:self.textAlignment];
}

[txt_field setValue:ColorFromHEX(@"#525252") forKeyPath:@"_placeholderLabel.textColor"];

对于具有多种颜色的设置属性文本字段占位符，

只需指定Text，

  //txtServiceText is your Textfield
 _txtServiceText.placeholder=@"Badal/ Shah";
    NSMutableAttributedString *mutable = [[NSMutableAttributedString alloc] initWithString:_txtServiceText.placeholder];
     [mutable addAttribute: NSForegroundColorAttributeName value:[UIColor whiteColor] range:[_txtServiceText.placeholder rangeOfString:@"Badal/"]]; //Replace it with your first color Text
    [mutable addAttribute: NSForegroundColorAttributeName value:[UIColor orangeColor] range:[_txtServiceText.placeholder rangeOfString:@"Shah"]]; // Replace it with your secondcolor string.
    _txtServiceText.attributedPlaceholder=mutable;

输出：-

另一个不需要子类化的选项-将占位符留空，并在“编辑”按钮的顶部放置一个标签。就像管理占位符一样管理标签（用户输入任何内容时清除。）