我想更改我在UITextField
控件中设置的占位符文本的颜色,使其变为黑色。
我宁愿这样做而不使用普通文本作为占位符,并且不必重写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
那么我应该能够做到这一点。但我不确定如何从这个方法中访问实际的占位符对象。
我想更改我在UITextField
控件中设置的占位符文本的颜色,使其变为黑色。
我宁愿这样做而不使用普通文本作为占位符,并且不必重写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
那么我应该能够做到这一点。但我不确定如何从这个方法中访问实际的占位符对象。
由于在 iOS 6 中的 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.
}
简单无痛,对某些人来说可能是一个简单的选择。
_placeholderLabel.textColor
不建议用于生产,Apple 可能会拒绝您的提交。
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]];
}
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}];
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。
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])
斯威夫特 4.2:
myTextfield.attributedPlaceholder =
NSAttributedString(string: "placeholder text", attributes: [NSAttributedString.Key.foregroundColor: UIColor.red])
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"];
注意
根据 Martin Alléus 的说法,这不再适用于 iOS 7。
为了更改情节提要中的占位符颜色,请使用下一个代码创建扩展。(请随时更新此代码,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)
}
}
}
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)
}
}
}
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)
}
}
}
在斯威夫特:
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])
}
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}];
我已经面临这个问题。在我的情况下,下面的代码是正确的。
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])
您还可以将以下代码用于iOS 13
let iVar = class_getInstanceVariable(UITextField.self, "_placeholderLabel")!
let placeholderLabel = object_getIvar(tf_mobile, iVar) as! UILabel
placeholderLabel.textColor = .red
希望,这可以帮助你。
有了这个,我们可以在 iOS 中改变 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"];
在 Swift 3.X 中
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])
你为什么不直接使用UIAppearance
方法:
[[UILabel appearanceWhenContainedIn:[UITextField class], nil] setTextColor:[UIColor whateverColorYouNeed]];
[textfield setValue:your_color forKeyPath:@"_placeholderLabel.textColor"];
希望能帮助到你。
注意: 当我们访问私有 API 时,Apple 可能会拒绝(0.01% 的机会)您的应用程序。两年以来,我在所有项目中都使用它,但 Apple 并没有要求这样做。
对于 Xamarin.iOS 开发人员,我从这个文档 https://developer.xamarin.com/api/type/Foundation.NSAttributedString/中找到了它
textField.AttributedPlaceholder = new NSAttributedString ("Hello, world",new UIStringAttributes () { ForegroundColor = UIColor.Red });
斯威夫特版本。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
}
}
}
iOS 6 及更高版本attributedPlaceholder
提供UITextField
. iOS 3.2 及更高版本setAttributes:range:
提供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;
此解决方案适用于 Swift 4.1
textName.attributedPlaceholder = NSAttributedString(string: textName.placeholder!, attributes: [NSAttributedStringKey.foregroundColor : UIColor.red])
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填充颜色。
对象-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
类别 FTW。可以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
带有警告的 Swift 5。
let attributes = [ NSAttributedString.Key.foregroundColor: UIColor.someColor ]
let placeHolderString = NSAttributedString(string: "DON'T_DELETE", attributes: attributes)
txtField.attributedPlaceholder = placeHolderString
需要注意的是,您必须在“DON'T_DELETE”所在的位置输入一个非空String
值,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时间。
覆盖drawPlaceholderInRect:
将是正确的方法,但由于 API(或文档)中的错误,它不起作用。
该方法永远不会在UITextField
.
另请参阅未调用 UITextField 上的 drawTextInRect
您可能会使用 digdog 的解决方案。由于我不确定这是否能通过 Apple 的审核,所以我选择了一个不同的解决方案:用我自己的标签覆盖文本字段,该标签模仿占位符的行为。
不过这有点乱。代码如下所示(注意我在 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,我找到了一种达到相同效果的方法。
我用所需格式放置了一个 uilabel 代替占位符并将其隐藏在
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
switch (textField.tag)
{
case 0:
lblUserName.hidden=YES;
break;
case 1:
lblPassword.hidden=YES;
break;
default:
break;
}
}
我同意这是一种解决方法,而不是真正的解决方案,但效果与此链接相同
注意:仍然适用于 iOS 7 :|
对于那些使用 Monotouch (Xamarin.iOS) 的人,这里是 Adam 的答案,翻译成 C#:
public class MyTextBox : UITextField
{
public override void DrawPlaceholder(RectangleF rect)
{
UIColor.FromWhiteAlpha(0.5f, 1f).SetFill();
new NSString(this.Placeholder).DrawString(rect, Font);
}
}
对于 iOS7 和更少,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];
}
}
对于设置具有多种颜色的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 :-
我需要保持占位符对齐,所以亚当的回答对我来说还不够。
为了解决这个问题,我使用了一个小变化,希望对你们中的一些人也有帮助:
- (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"];
另一个不需要子类化的选项 - 将占位符留空,并在编辑按钮顶部放置标签。像管理占位符一样管理标签(一旦用户输入任何内容就清除..)
在斯威夫特 3
import UIKit
let TEXTFIELD_BLUE = UIColor.blue
let TEXTFIELD_GRAY = UIColor.gray
class DBTextField: UITextField {
/// Tetxfield Placeholder Color
@IBInspectable var palceHolderColor: UIColor = TEXTFIELD_GRAY
func setupTextField () {
self.attributedPlaceholder = NSAttributedString(string:self.placeholder != nil ? self.placeholder! : "",
attributes:[NSForegroundColorAttributeName: palceHolderColor])
}
}
class DBLocalizedTextField : UITextField {
override func awakeFromNib() {
super.awakeFromNib()
self.placeholder = self.placeholder
}
}
我会建议另一种解决方案。由于占位符文本使用文本字段的默认字体设置,只需将初始字体颜色设置为您想要的占位符字体颜色即可。然后设置你的 UITextField 的委托并实现以下方法:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
//set color for text input
textField.textColor = [UIColor blackColor];
return YES;
}
- (BOOL)textFieldShouldClear:(UITextField *)textField
{
//set color for placeholder text
textField.textColor = [UIColor redColor];
return YES;
}
因此,如果用户开始在文本字段中输入,文本的颜色将变为黑色,并且在再次清除文本字段后,占位符文本将再次显示为红色。
干杯,安卡