你可以通过设置leftView来设置UITextField的文本插入。

是这样的:

UITextField *yourTextField = [[UITextField alloc] init];
UIView *leftView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 5, 5)];
leftView.backgroundColor = [UIColor clearColor];
yourTextField.leftViewMode = UITextFieldViewModeAlways;
yourTextField.leftView = leftView;

抛出另一个不需要子类化的解决方案:

UITextField *txtField = [UITextField new];
txtField.borderStyle = UITextBorderStyleRoundedRect;

// grab BG layer
CALayer *bgLayer = txtField.layer.sublayers.lastObject;
bgLayer.opacity = 0.f;

// add new bg view
UIView *bgView = [UIView new];
bgView.backgroundColor = [UIColor whiteColor];
bgView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
bgView.userInteractionEnabled = NO;

[txtField addSubview: bgView];
[txtField sendSubviewToBack: bgView];

在iOS 7和iOS 8上测试。这两个工作。苹果仍然有可能修改UITextField的层层次结构，把事情搞砸了。

你可以通过使文本字段成为UITextField的子类并覆盖-textRectForBounds:方法来调整文本在文本字段中的位置。

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

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;

重写-textRectForBounds:只会改变占位符文本的插入。要改变可编辑文本的插入，你还需要重写-editingRectForBounds:

// placeholder position
- (CGRect)textRectForBounds:(CGRect)bounds {
     return CGRectInset(bounds, 10, 10);
}

// text position
- (CGRect)editingRectForBounds:(CGRect)bounds {
     return CGRectInset(bounds, 10, 10);
}