另一个需要考虑的问题是，如果你在添加填充的地方有多个UITextField，就要为每个文本字段创建一个单独的UIView——因为它们不能共享。

就像这样子类UITextField (Swift版本):

import UIKit

class CustomTextField: UITextField {

    override func textRectForBounds(bounds: CGRect) -> CGRect {
       return CGRectInset(bounds, 25.0, 0)
    }

    override func editingRectForBounds(bounds: CGRect) -> CGRect {
       return self.textRectForBounds(bounds)
    }

}

这增加了25.0点的水平填充两边。

Swift 3的更新版本:

@IBDesignable
class FormTextField: UITextField {

    @IBInspectable var paddingLeft: CGFloat = 0
    @IBInspectable var paddingRight: CGFloat = 0

    override func textRect(forBounds bounds: CGRect) -> CGRect {
        return CGRect(x: bounds.origin.x + paddingLeft, y: bounds.origin.y, width: bounds.size.width - paddingLeft - paddingRight, height: bounds.size.height)
    }

    override func editingRect(forBounds bounds: CGRect) -> CGRect {
        return textRect(forBounds: bounds)
    }
}

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

Objective C代码

MyTextField.h

#import <UIKit/UIKit.h>

@interface MyTextField : UITextField

@property (nonatomic) IBInspectable CGFloat padding;

@end

MyTextField.m

#import "MyTextField.h"

IB_DESIGNABLE
@implementation MyTextField

@synthesize padding;

-(CGRect)textRectForBounds:(CGRect)bounds{
    return CGRectInset(bounds, padding, padding);
}

-(CGRect)editingRectForBounds:(CGRect)bounds{
    return [self textRectForBounds:bounds];
}

@end

Swift 2.0版本:

let paddingView: UIView = UIView(frame: CGRectMake(0, 0, 5, 20))
textField.leftView = paddingView
textField.leftViewMode = UITextFieldViewMode.Always;