下面是在Swift 3中编写的相同子类UITextField。它与之前的Swift版本有很大的不同，正如你将看到的:

import UIKit

class MyTextField: UITextField
    {
    let inset: CGFloat = 10

    // placeholder position
    override func textRect(forBounds bounds: CGRect) -> CGRect
        {
        return bounds.insetBy(dx: inset, dy: inset)
        }

    // text position
    override func editingRect(forBounds bounds: CGRect) -> CGRect
        {
        return bounds.insetBy(dx: inset, dy: inset)
        }

    override func placeholderRect(forBounds bounds: CGRect) -> CGRect
        {
        return bounds.insetBy(dx: inset, dy: inset)
        }
    }

顺便说一句，如果你只想控制一侧的插入，你也可以像下面这样做。如果你把一个图像放在UITextField的顶部，但你想让它在用户看来是在文本框中，那么这个只调整左边插图的特殊例子就很方便了:

    override func editingRect(forBounds bounds: CGRect) -> CGRect
        {
        return CGRect.init(x: bounds.origin.x + inset, y: bounds.origin.y, width: bounds.width - inset, height: bounds.height)
        }

快速解决没有子类&也检查

extension UITextField {
    @IBInspectable var textInsets: CGPoint {
            get {
                return CGPoint.zero
            }
            set {
                layer.sublayerTransform = CATransform3DMakeTranslation(newValue.x, newValue.y, 0);
            }
        }
}

我做到了:

myTextField.layer.sublayerTransform = CATransform3DMakeTranslation(5, 0, 0);

当然记得导入QuartzCore并将框架添加到您的项目中。

我子类化UITextField来处理这个，它支持左，上，右和底部的插入，以及清除按钮的定位。

MRDInsetTextField.h

#import <UIKit/UIKit.h>

@interface MRDInsetTextField : UITextField

@property (nonatomic, assign) CGRect inset;

@end

MRDInsetTextField.m

#import "MRDInsetTextField.h"

@implementation MRDInsetTextField

- (id)init
{
    self = [super init];
    if (self) {
        _inset = CGRectZero;
    }
    return self;
}

- (id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];
    if (self) {
        _inset = CGRectZero;
    }
    return self;
}

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        _inset = CGRectZero;
    }
    return self;
}

- (void)setInset:(CGRect)inset {
    _inset = inset;

    [self setNeedsLayout];
}

- (CGRect)getRectForBounds:(CGRect)bounds withInset:(CGRect)inset {

    CGRect newRect = CGRectMake(
                         bounds.origin.x + inset.origin.x,
                         bounds.origin.y + inset.origin.y,
                         bounds.origin.x + bounds.size.width - inset.origin.x - inset.size.width,
                         bounds.origin.y + bounds.size.height - inset.origin.y - inset.size.height
                         );

    return newRect;
}

- (CGRect)textRectForBounds:(CGRect)bounds {
    return [self getRectForBounds:[super textRectForBounds:bounds] withInset:_inset];
}

- (CGRect)placeholderRectForBounds:(CGRect)bounds {
    return [self getRectForBounds:bounds withInset:_inset];
}

- (CGRect)editingRectForBounds:(CGRect)bounds {
    return [self getRectForBounds:[super editingRectForBounds:bounds] withInset:_inset];
}

- (CGRect)clearButtonRectForBounds:(CGRect)bounds {
    return CGRectOffset([super clearButtonRectForBounds:bounds], -_inset.size.width, _inset.origin.y/2 - _inset.size.height/2);
}

@end

*_someTextField*来自nib/storyboard视图，带有MRDInsetTextField自定义类的用法示例

[(MRDInsetTextField*)_someTextField setInset:CGRectMake(5, 0, 5, 0)]; // left, top, right, bottom inset

如果你想改变TOP和LEFT缩进只有这样

//占位符

- (CGRect)textRectForBounds:(CGRect)bounds {

CGRect frame = bounds;
frame.origin.y = 3;
 frame.origin.x = 5;
bounds = frame;
return CGRectInset( bounds , 0 , 0 );
}

//文本位置

- (CGRect)editingRectForBounds:(CGRect)bounds {

CGRect frame = bounds;
frame.origin.y = 3;
 frame.origin.x = 5;
bounds = frame;
return CGRectInset( bounds , 0 , 0 );
}

下面是一个全面的Swift答案，包括一个leftView(自定义图标)和一个自定义清除按钮，两者都设置在界面生成器中，具有可定制的insets。

import UIKit

@IBDesignable
class InsetTextField: UITextField {
@IBInspectable var leftInset:CGFloat = 0
@IBInspectable var rightInset:CGFloat = 0
@IBInspectable var icon:UIImage? { didSet {
    let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 16, height: 16))
    imageView.image = icon
    self.leftView = imageView
    self.leftViewMode = .Always
} }

@IBInspectable var clearButton:UIImage? { didSet {
    let button = UIButton(type: .Custom)
    button.setImage(clearButton, forState: .Normal)
    button.addTarget(self, action: "clear", forControlEvents: UIControlEvents.TouchUpInside)
    button.frame = CGRect(x: 0, y: 0, width: 18, height: 18)
    self.rightView = button
    self.rightViewMode = .WhileEditing
} }

func clear() {
    self.text = ""
}

override func leftViewRectForBounds(bounds: CGRect) -> CGRect {
    var height:CGFloat = 0
    var width:CGFloat = 0
    if let leftView = self.leftView {
        height = leftView.bounds.height
        width = leftView.bounds.width
    }

    return CGRect(x: leftInset, y: bounds.height/2 - height/2, width: width, height: height)
}

override func rightViewRectForBounds(bounds: CGRect) -> CGRect {
    var height:CGFloat = 0
    var width:CGFloat = 0
    if let rightView = self.rightView {
        height = rightView.bounds.height
        width = rightView.bounds.width
    }

    return CGRect(x: bounds.width - width - rightInset, y: bounds.height/2 - height/2, width: width, height: height)
}

}