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 );
}

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);
            }
        }
}

Swift 5版本的克里斯托弗的答案与额外的用法示例

import UIKit

private class InsetTextField: UITextField {
    var insets: UIEdgeInsets

    init(insets: UIEdgeInsets) {
        self.insets = insets
        super.init(frame: .zero)
    }

    required init(coder aDecoder: NSCoder) {
        fatalError("not intended for use from a NIB")
    }

    // placeholder position
    override func textRect(forBounds bounds: CGRect) -> CGRect {
         return super.textRect(forBounds: bounds.inset(by: insets))
    }
 
    // text position
    override func editingRect(forBounds bounds: CGRect) -> CGRect {
         return super.editingRect(forBounds: bounds.inset(by: insets))
    }
}

extension UITextField {

    class func textFieldWithInsets(insets: UIEdgeInsets) -> UITextField {
        return InsetTextField(insets: insets)
    }

}

用法:-

class ViewController: UIViewController {

  private let passwordTextField: UITextField = {

        let textField = UITextField.textFieldWithInsets(insets: UIEdgeInsets(top: 10, left: 15, bottom: 10, right: 15))
     // ---
   
        return textField
    }()

}

对于那些正在寻找更简单解决方案的人来说。

在UIView中添加UITextField。为了模拟文本框周围的插入，我保持左10像素，宽度比视图小20像素。对于文本框周围的圆角边框，请使用视图的边框

viewBG.layer.cornerRadius = 8.0;
viewBG.layer.borderColor = [UIColor darkGrayColor].CGColor;
viewBG.layer.borderWidth = 1.0;

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)
}

}

为UITextField添加填充的一个好方法是子类化UITextField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 = UIEdgeInsetsMake(0, 0, 0, 0);
    }
    return self;
}

-(id)initWithCoder:(NSCoder *)aDecoder{
    self = [super initWithCoder:aDecoder];
    if(self){
        self.edgeInsets = UIEdgeInsetsMake(0, 0, 0, 0);
    }
    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