修改UITextFeild占位符字符串的颜色

一. 修改占位字符串的 颜色：

=======方法一 ======================================

#import "ViewController.h"
#import "MyTextField.h"

@interface ViewController ()
{
   UITextField *_textF;
}
@end

@implementation ViewController

- (void)viewDidLoad {
   [super viewDidLoad];
   
   self.view.backgroundColor=[UIColor whiteColor];
   
   MyTextField *textF = [[MyTextField alloc] initWithFrame:CGRectMake(100, 100, 200, 40)];
   _textF = textF;
   [self.view addSubview:textF];
   
   textF.backgroundColor = [UIColor whiteColor];
   textF.borderStyle = UITextBorderStyleRoundedRect;
   textF.leftViewMode = UITextFieldViewModeWhileEditing;
   
   UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 30, 30)];
   btn.backgroundColor=[UIColor greenColor];
   textF.leftView = btn;
   
   textF.placeholder = @"哈哈";
   
   UIColor *color = [UIColor colorWithRed:100/255.0 green:200/255.0 blue:100/255.0 alpha:0.7];
   [textF setValue:color forKeyPath:@"_placeholderLabel.textColor"];//修改占位字符串“哈哈”的颜色
   
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
   [_textF resignFirstResponder];
}

@end


======= 方法二 =================================

#import "MyTextField.h"

@implementation MyTextField

- (void)drawPlaceholderInRect:(CGRect)rect{
   UIColor *placeholderColor = [UIColor redColor];//设置颜色
   [placeholderColor setFill];
   
   CGRect placeholderRect = CGRectMake(rect.origin.x+30, (rect.size.height- self.font.pointSize)/5, rect.size.width, self.font.pointSize);//设置距离
   
   NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
   style.lineBreakMode = NSLineBreakByTruncatingMiddle;
   style.alignment = self.textAlignment;
   NSDictionary *attr = [NSDictionary dictionaryWithObjectsAndKeys:style,NSParagraphStyleAttributeName, self.font, NSFontAttributeName, placeholderColor, NSForegroundColorAttributeName, nil];
   
   [self.placeholder drawInRect:placeholderRect withAttributes:attr];
}

@end



#import "ViewController.h"
#import "MyTextField.h"

@interface ViewController ()
{
   UITextField *_textF;
}
@end

@implementation ViewController

- (void)viewDidLoad {
   [super viewDidLoad];
   
   self.view.backgroundColor=[UIColor whiteColor];
 

   MyTextField *textF = [[MyTextField alloc] initWithFrame:CGRectMake(100, 100, 200, 40)];
   _textF = textF;
   [self.view addSubview:textF];
   
   textF.backgroundColor = [UIColor whiteColor];
   textF.borderStyle = UITextBorderStyleRoundedRect;
   textF.leftViewMode = UITextFieldViewModeWhileEditing;
   
   UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 30, 30)];
   btn.backgroundColor=[UIColor greenColor];
   textF.leftView = btn;
   
   textF.placeholder = @"哈哈哈哈哈哈";
   
//    UIColor *color = [UIColor colorWithRed:100/255.0 green:200/255.0 blue:100/255.0 alpha:0.7];
//    [textF setValue:color forKeyPath:@"_placeholderLabel.textColor"];//修改占位字符串“哈哈”的颜色
   
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
   [_textF resignFirstResponder];
}

@end