ios 当遇到继承与UISearchBar失败后

作者: 雪_晟 | 来源:发表于2017-06-19 13:46 被阅读118次

项目中有需要检索功能的时候，就需要使用到UISearchBar,如果想做类似微信那种点击搜索框进入下一个页面，同时将搜索框迁移到Nabbar上。可能你会想使用UISearchController,可是使用的时候感觉要改的东西很多，能力有限，就自己来了。

示意图看一下：

SearchBar.gif

首先是要确定UISearchBar 的布局，有几个方法，
1、打印子视图
2、看层级视图关系
3、拿到私有变量

打印子视图其实最好还是结合层级关系，

UISearchBar层级关系如下：

层级.png

可以看到主要是由一个背景ImageView与UITextFild组成。
打印一下子视图如下：

  for (UIView* subview  in [_searchBar.subviews firstObject].subviews) {
            NSLog(@"%@", subview.class);
}
2017-06-19 13:01:22.930 LXSearchBar[6314:170257] UISearchBarBackground
2017-06-19 13:01:22.931 LXSearchBar[6314:170257] UISearchBarTextField

通过debug 调试可以看清具体的类型：

层级2.png

说明 UISearchBarTextField 的类型是UITextFild类型

关于通过runtime拿到私有属性方法如下：

第一步：引入头文件：#import <objc/runtime.h>
第二步：方法：

1unsigned int outCount = 0;
    Ivar *ivars = class_copyIvarList([UISearchBar class], &outCount);
    
    for (NSInteger i = 0; i < outCount; ++i) {
        // 遍历取出该类成员变量
        Ivar ivar = *(ivars + i);
        
        NSLog(@"\n name = %s  ======= type = %s", ivar_getName(ivar),ivar_getTypeEncoding(ivar));
    }
    
    // 根据内存管理原则释放指针
    free(ivars);

清楚UISearchBar 的层级关系后，我们可以通过遍历，去设置我们需要的改变的一些属性：

通过上面可以很清楚的知道，UISearchBar是由一张背景图片和UITextField组成的，所以已经很明确了。
如果要修改输入区域的颜色等等，可以通过设置UITextField，如果设置背景图，可以设置一张颜色生成的图片作为背景。

for (UIView* subview  in [_searchBar.subviews firstObject].subviews) {
            NSLog(@"%@", subview.class);
            // 打印出两个结果:
            /*
             UISearchBarBackground
             UISearchBarTextField
             */
            
            if ([subview isKindOfClass:[UITextField class]]) {
                
                searchField = (UITextField*)subview;
                // leftView就是放大镜
                // searchField.leftView=nil;
                // 删除searchBar输入框的背景
                [searchField setBackground:nil];
                [searchField setBorderStyle:UITextBorderStyleNone];
                searchField.backgroundColor = self.searchAreaColor;
                // 设置圆角
                searchField.layer.cornerRadius = 15;
                searchField.layer.masksToBounds = YES;
                break;
            }
            if ([subview isKindOfClass:[NSClassFromString(@"UISearchBarBackground") class]]) {
                UIImageView *backImageView = (UIImageView *)subview;
                
                backImageView.image =[UIImage imageWithColor:[UIColor hexStringToColor:@"dddddd"] size:_searchBar.frame.size];
                    }
            

        }

======插一个颜色生成图片的方法---

+(UIImage *)imageWithColor:(UIColor*)color size:(CGSize)size{
    
    CGRect rect =CGRectMake(0,0, size.width, size.height);
    
    UIGraphicsBeginImageContext(rect.size);
    
    CGContextRef context =UIGraphicsGetCurrentContext();
    
    CGContextSetFillColorWithColor(context, [color CGColor]);
    
    CGContextFillRect(context, rect);
    
    UIImage *image =UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return image;
    
}

通过上面我们已经修改了搜索区域的颜色已经背景图；

如果我们要修改UISearchBar的取消按钮的文字或者颜色，就需要接下来的设置，网上看到可以通过上面的方法直接通过KVC获取_cancelButton，因为iOS升级的原因，目前已经拿不到了，需要我们设置取消按钮显示时候可以拿到取消按钮,设置时机就是在即将开始编辑的时候设置显示。

-(BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar{
    searchBar.showsCancelButton = YES;
    // 然后设置searchBar的tint颜色
    //    [searchBar setBarTintColor:[UIColor whiteColor]];
    for(id cc in [searchBar subviews]){
        for (id subView in [cc subviews]) {
            if ([subView isKindOfClass:[UITextField class]]) {

            }else if([subView isKindOfClass:[UIButton class]]){
                // 修改取消按钮
                UIButton *btn = (UIButton *)subView;
                [btn setTitle:self.cancelBtnName forState:UIControlStateNormal];
                [btn setTitleColor:self.canceBtnColor forState:(UIControlStateNormal)];
            }
        }
    }
    
    return YES;
}

隐藏取消按钮的时机：

-(void)searchBarCancelButtonClicked:(UISearchBar *)searchBar{
    searchBar.showsCancelButton = NO;
    [searchBar resignFirstResponder];
    
}

这样我们自定义UISearchBar就基本上完成了。

接下来继承与UISearchBar ，可是失败了。

新建类继承与UISearBar后，打印的层级关系如下：

  for (UIView* subview  in [_searchBar.subviews firstObject].subviews) {
            NSLog(@"%@", subview.class);
}
2017-06-19 13:01:22.930 LXSearchBar[6314:170257] UISearchBarBackground

太操蛋了，`只有一个背景图`

所以放弃自定义UISearchBar。可以为了复用，可以写一个基类，暴露一个searchBar属性。

#import <UIKit/UIKit.h>

@interface LXSearchController : UIViewController<UISearchBarDelegate>

@property(nonatomic,strong)UISearchBar *searchBar;

@end

#import "LXSearchController.h"

@interface LXSearchController ()
@property(nonatomic,strong)UIColor *searchAreaColor;//搜索区域的颜色
@property(nonatomic,copy)NSString *cancelBtnName;//取消按钮的名字
@property(nonatomic,strong)UIColor *canceBtnColor; //取消按钮的颜色
@property(nonatomic,strong)UIColor *backImageviewColor;//背景图的颜色
@property(nonatomic,assign)UIOffset mouseOffSet;//光标位置

@end

@implementation LXSearchController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.navigationController.navigationBar.translucent = NO;
    self.navigationController.navigationBar.barTintColor = [UIColor hexStringToColor:@"#393d63"];
    self.extendedLayoutIncludesOpaqueBars = YES;
    self.automaticallyAdjustsScrollViewInsets = NO;
    self.view.backgroundColor =[UIColor whiteColor];
   
}
-(BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar{
    searchBar.showsCancelButton = YES;
    // 然后设置searchBar的tint颜色
    //    [searchBar setBarTintColor:[UIColor whiteColor]];
    for(id cc in [searchBar subviews]){
        for (id subView in [cc subviews]) {
            if ([subView isKindOfClass:[UITextField class]]) {

            }else if([subView isKindOfClass:[UIButton class]]){
                // 修改取消按钮
                UIButton *btn = (UIButton *)subView;
                [btn setTitle:self.cancelBtnName forState:UIControlStateNormal];
                [btn setTitleColor:self.canceBtnColor forState:(UIControlStateNormal)];
            }
        }
    }
    
    return YES;
}

-(UISearchBar *)searchBar{
    if (!_searchBar) {
       _searchBar = [[UISearchBar alloc] initWithFrame:(CGRectMake(0, 64, Device_Width, 40))];
        _searchBar.placeholder = @"姓名/昵称/电话";
        _searchBar.delegate = self;
        // 样式
        _searchBar.tintColor = self.canceBtnColor;
        _searchBar.searchBarStyle = UISearchBarStyleProminent;
        
//        UISearchBar有一个searchTextPositionAdjustment属性就是设置光标偏移量的，类型为UIOffset结构体，赋值即可
        
       //第一个值是水平偏移量，第二个是竖直方向的偏移量
        _searchBar.searchTextPositionAdjustment = self.mouseOffSet;
        // ** 自定义searchBar的样式 **
        UITextField* searchField = nil;
        // 注意searchBar的textField处于孙图层中
//        _searchBar.backgroundColor = ;
        for (UIView* subview  in [_searchBar.subviews firstObject].subviews) {
            NSLog(@"%@", subview.class);
            // 打印出两个结果:
            /*
             UISearchBarBackground
             UISearchBarTextField
             */
            
            if ([subview isKindOfClass:[UITextField class]]) {
                
                searchField = (UITextField*)subview;
                // leftView就是放大镜
                // searchField.leftView=nil;
                // 删除searchBar输入框的背景
                [searchField setBackground:nil];
                [searchField setBorderStyle:UITextBorderStyleNone];
                searchField.backgroundColor = self.searchAreaColor;
                // 设置圆角
                searchField.layer.cornerRadius = 15;
                searchField.layer.masksToBounds = YES;
                break;
            }
            if ([subview isKindOfClass:[NSClassFromString(@"UISearchBarBackground") class]]) {
                UIImageView *backImageView = (UIImageView *)subview;
                
                backImageView.image =[UIImage imageWithColor:[UIColor hexStringToColor:@"dddddd"] size:_searchBar.frame.size];
                    }
            

        }

    }
    return _searchBar;
}
-(void)viewWillDisappear:(BOOL)animated{
    [super viewWillDisappear:animated];
    self.searchBar.showsCancelButton = NO;
    [ self.searchBar resignFirstResponder];
    [self.view endEditing:YES];
    
}
-(void)searchBarCancelButtonClicked:(UISearchBar *)searchBar{
    searchBar.showsCancelButton = NO;
    [searchBar resignFirstResponder];
    
}
-(UIColor *)searchAreaColor{
    if (!_searchAreaColor) {
        _searchAreaColor =[UIColor hexStringToColor:@"F0EFF5"];
    }
    return _searchAreaColor;
}
-(NSString *)cancelBtnName{
    if (!_cancelBtnName) {
        _cancelBtnName = @"取消";
    }
    return _cancelBtnName;
}
-(UIColor *)canceBtnColor{
    if (!_canceBtnColor) {
        _canceBtnColor =[UIColor hexStringToColor:@"64c961"];
    }
    return _canceBtnColor;
}
-(UIColor *)backImageviewColor{
    if (!_backImageviewColor) {
        _backImageviewColor =[UIColor hexStringToColor:@"dddddd"];
    }
    return _backImageviewColor;
}
-(UIOffset)mouseOffSet{
   
   UIOffset  offset=  UIOffsetMake(10, 0);
    return offset;
}
@end

至于UISearchBar添加到父视图的操作放在子类里进行。

新建一个类继承与刚才的基类：

@interface NextController : LXSearchController

@end

点击UISearchBar就进入搜索结果页面，并且添加相应的过渡动画,UISearchBar放在NabBar下面：

#import "NextController.h"
#import "SearchResultController.h"
@interface NextController ()

@end

@implementation NextController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    [self.view addSubview:self.searchBar];
    
    
}
-(BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar{

    
    SearchResultController *nextVc =[[SearchResultController alloc]init];
    
    CATransition* transition = [CATransition animation];
    transition.duration = 0.3;
    transition.type = kCATransitionFade;            //改变视图控制器出现的方式
    
    transition.subtype = kCATransitionFromTop;     //出现的位置
    
    [self.navigationController.view.layer addAnimation:transition forKey:kCATransition];
    
    [self.navigationController pushViewController:nextVc animated:NO];
    
    
    return YES;
}

搜索结果类进行同样的处理，继承与刚才的基类,返回按钮做一些处理，以及在加载UISearchBar的时候让UISearchBar就进入编辑状态 `[self searchBarShouldBeginEditing:self.searchBar];`,并且把UISearBar设置为titleView:`self.navigationItem.titleView = self.searchBar;`

#import "SearchResultController.h"

@interface SearchResultController ()

@end

@implementation SearchResultController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    UIView *view =[UIView new];
    self.navigationItem.leftBarButtonItem =[[UIBarButtonItem alloc]initWithCustomView:view];
    

    [self searchBarShouldBeginEditing:self.searchBar];
    [self.searchBar becomeFirstResponder];
    self.navigationItem.titleView = self.searchBar;
}

-(void)searchBarCancelButtonClicked:(UISearchBar *)searchBar{
    searchBar.showsCancelButton = NO;
    [searchBar resignFirstResponder];
    
    [self.navigationController popViewControllerAnimated:NO];
}

示意图看一下：

SearchBar.gif

demo地址：自定义UISearchBar

ios 当遇到继承与UISearchBar失败后

打印子视图其实最好还是结合层级关系，

说明 UISearchBarTextField 的类型是UITextFild类型

关于通过runtime拿到私有属性方法如下：

太操蛋了，`只有一个背景图`

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iOS Developer

ios 当遇到继承与UISearchBar失败后

打印子视图其实最好还是结合层级关系，

说明 UISearchBarTextField 的类型是UITextFild类型

关于通过runtime拿到私有属性方法如下：

太操蛋了，只有一个背景图

相关文章

网友评论

延伸阅读

深度阅读

栏目导航

热点阅读

iOS Developer

太操蛋了，`只有一个背景图`