为UITextField添加填充的一个好方法是子类化并添加一个edgeInsets属性。然后设置edgeInsets和UITextField将相应地绘制。对于自定义的leftView或rightView集，这也能正确地发挥作用。

OSTextField.h

#import <UIKit/UIKit.h>

@interface OSTextField : UITextField

@property (nonatomic, assign) UIEdgeInsets edgeInsets;

@end

OSTextField.m

#import "OSTextField.h"

@implementation OSTextField

- (id)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if (self) {
        self.edgeInsets = UIEdgeInsetsZero;
    }
    return self;
}

-(id)initWithCoder:(NSCoder *)aDecoder{
    self = [super initWithCoder:aDecoder];
    if(self){
        self.edgeInsets = UIEdgeInsetsZero;
    }
    return self;
}

- (CGRect)textRectForBounds:(CGRect)bounds {
    return [super textRectForBounds:UIEdgeInsetsInsetRect(bounds, self.edgeInsets)];
}

- (CGRect)editingRectForBounds:(CGRect)bounds {
    return [super editingRectForBounds:UIEdgeInsetsInsetRect(bounds, self.edgeInsets)];
}

@end

你不能设置填充。而是有一个UIView，里面有你的背景图像和UITextField。设置UITextField的宽度为UIViewWidth-(paddingSize x 2)和高度相似，然后设置它在点paddingSize,paddingSize。

我发现了一个整洁的小hack来设置左侧填充的确切情况。

基本上，你设置UITextField的leftView属性为你想要的填充大小的空视图:

UIView *paddingView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 5, 20)];
textField.leftView = paddingView;
textField.leftViewMode = UITextFieldViewModeAlways;

对我来说简直就是魔法!

在Swift 3/ Swift 4中，可以通过这样做来实现

let paddingView: UIView = UIView(frame: CGRect(x: 0, y: 0, width: 5, height: 20))
textField.leftView = paddingView
textField.leftViewMode = .always

以下是如何在SWIFT中实现这一点

@IBOutlet weak var yourTextField: UITextField!

override func viewDidLoad() {
super.viewDidLoad()
let paddingView = UIView(frame: CGRectMake(0, 0, 10, self.yourTextField.frame.height))
yourTextField.leftView = paddingView
yourTextField.leftViewMode = UITextFieldViewMode.Always
}
}

资源

下面是一个Swift代码，在UITextfield中提供填充

 func txtPaddingVw(txt:UITextField) {
     let paddingView = UIView(frame: CGRectMake(0, 0, 10, 10))
     txt.leftViewMode = .Always
     txt.leftView = paddingView
 }

调用using

self.txtPaddingVw(txtPin)

基于Evil Trout的回答，你可能想要创建一个类别，使它更容易在多个应用程序中使用。

头文件:

@interface UITextField (PaddingText)

-(void) setLeftPadding:(int) paddingValue;

-(void) setRightPadding:(int) paddingValue;
@end

实现文件:

#import "UITextField+PaddingText.h"

@implementation UITextField (PaddingText)

-(void) setLeftPadding:(int) paddingValue
{
    UIView *paddingView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, paddingValue, self.frame.size.height)];
    self.leftView = paddingView;
    self.leftViewMode = UITextFieldViewModeAlways;
}

-(void) setRightPadding:(int) paddingValue
{
    UIView *paddingView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, paddingValue, self.frame.size.height)];
    self.rightView = paddingView;
    self.rightViewMode = UITextFieldViewModeAlways;
}

@end

使用的例子

#import "UITextField+PaddingText.h"

[self.YourTextField setLeftPadding:20.0f];

希望这对你们有所帮助

干杯