我想改变我在UITextField控件中设置的占位符文本的颜色,使其为黑色。
我更喜欢这样做,而不使用普通文本作为占位符,并且不得不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
那么我就能做这个了。但是我不确定如何从这个方法中访问实际的占位符对象。
我想改变我在UITextField控件中设置的占位符文本的颜色,使其为黑色。
我更喜欢这样做,而不使用普通文本作为占位符,并且不得不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
那么我就能做这个了。但是我不确定如何从这个方法中访问实际的占位符对象。
当前回答
在iOS7中处理垂直和水平对齐以及占位符的颜色。drawwinrect和drawAtPoint不再使用当前上下文的fillColor。
https://developer.apple.com/library/ios/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/CustomTextProcessing/CustomTextProcessing.html
卷-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
其他回答
此解决方案适用于Swift 4.1
textName.attributedPlaceholder = NSAttributedString(string: textName.placeholder!, attributes: [NSAttributedStringKey.foregroundColor : UIColor.red])
在Swift 3中
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
}
}
重写drawPlaceholderInRect:将是正确的方式,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上被调用。
参见drawTextInRect on UITextField not called
你可以使用digdog的解决方案。因为我不确定这是否通过了苹果的审查,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,模仿占位符行为。
这有点乱。 代码看起来像这样(注意,我在TextField的子类中这样做):
@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;
}
你可以改变占位符文本颜色的任何颜色,你想通过使用下面的代码。
UIColor *color = [UIColor lightTextColor];
YOURTEXTFIELD.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"PlaceHolder Text" attributes:@{NSForegroundColorAttributeName: color}];
自从ios6在UIViews中引入了带属性字符串,就可以像这样为占位符文本分配颜色:
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.
}