uitextfield 设置左图标以及图标文字间距，输入框背景图切换

[code]#import <UIKit/UIKit.h>
@interface YLSTextField : UITextField
@end

#import "YLSTextField.h"
@implementation YLSTextField
//改变文字位置
-(CGRect) textRectForBounds:(CGRect)bounds{
    CGRect iconRect=[super textRectForBounds:bounds];
    iconRect.origin.x+=10;
    return iconRect;
}
//改变编辑时文字位置
-(CGRect) editingRectForBounds:(CGRect)bounds{
    CGRect iconRect=[super editingRectForBounds:bounds];
    iconRect.origin.x+=10;
    return iconRect;
}
@end

[code]self.loginuser.delegate=self;
    self.loginpass.delegate=self;
    //设置输入框左边图标
    UIImageView *image1=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"user.png"]];
    image1.frame=CGRectMake(0, 0, 27, 27);
    self.loginuser.leftView=image1;
    self.loginuser.leftViewMode=UITextFieldViewModeAlways;
    UIImageView *image2=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"mima.png"]];
    image2.frame=CGRectMake(0, 0, 27, 27);
    self.loginpass.leftView=image2;
    self.loginpass.leftViewMode=UITextFieldViewModeAlways;

[code]//改变输入框背景图片
-(void)textFieldDidBeginEditing:(YLSTextField *)textField{
    if (textField.tag==3) {
        [self.loginuser setBackground:[UIImage imageNamed:@"inputlan.png"]];
    }else if(textField.tag==4){
        [self.loginpass setBackground:[UIImage imageNamed:@"inputlan.png"]];
    }
}

-(void)textFieldDidEndEditing:(YLSTextField *)textField{
    if (textField.tag==3) {
        [self.loginuser setBackground:[UIImage imageNamed:@"inputhui.png"]];
    }else if(textField.tag==4){
        [self.loginpass setBackground:[UIImage imageNamed:@"inputhui.png"]];
    }
}