在开发中经常会用到搜索功能，但系统的searchBar很难满足UI的要求，就需要自定义searchBar了，直接上代码

#import <UIKit/UIKit.h>

@interface WXSearchBar : UITextField

+ (instancetype)searchBarWithFrame:(CGRect)frame;

@end```

import "WXSearchBar.h"

@implementation WXSearchBar

• (instancetype)initWithFrame:(CGRect)frame
  {
  self = [super initWithFrame:frame];

  if (self) {
  self.font = [UIFont systemFontOfSize:15];
  self.placeholder = @"请输入查询条件";
  self.background = [UIImage imageNamed:@""];

    UIImageView *searchIcon = [[UIImageView alloc] init];
    searchIcon.frame = CGRectMake(0, 0, 30, 30);
    searchIcon.contentMode = UIViewContentModeCenter;
    searchIcon.image = [UIImage imageNamed:@""];
    
    self.leftView = searchIcon;
    self.leftViewMode = UITextFieldViewModeAlways;
  

  }

  return self;

}

• (instancetype)searchBarWithFrame:(CGRect)frame
  {
  return [[self alloc] initWithFrame:frame];
  }```