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;

斯威夫特

    // adjust place holder text
    let paddingView = UIView(frame: CGRectMake(0, 0, 10, usernameOrEmailField.frame.height))
    usernameOrEmailField.leftView = paddingView
    usernameOrEmailField.leftViewMode = UITextFieldViewMode.Always

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

使用textRectForBounds:是正确的方法。我已经在我的子类中包装了这个，所以你可以简单地使用textEdgeInsets。看到SSTextField。

我通常尽量避免子类化，但如果你已经:

// add a property 
@property (nonatomic) UIEdgeInsets edgeInsets;

// and override:

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

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

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);
            }
        }
}