UITextFieldからenterBackground、アプリケーションクラッシュ

Question

カスタムUITextField：クリックしたTextField入力で、キーボードポップアップの後に背景を入力して再びフォアグラウンドに入ると、アプリクラッシュ！あなたは、TextField入力、背景や前景の変換をクリックしないと

、それは正常であり、コードの一部：

@implementatio BKSearchViewController 
    - (void)setNavgationView { 
     BKSearchBar *searchBar = [[BKSearchBar alloc] initWithFrame:CGRectMake(20, 27, kScreenWidth - 90, 30)]; 
     searchBar.placeholder = @"输入昵称/拜托号"; 
     searchBar.delegate = self; 
     [searchBar setKeyboardType:UIKeyboardTypeDefault]; 
     [searchBar setReturnKeyType:UIReturnKeySearch]; 
     [searchBar setPlaceholderColor:kcallColor(@"a4a4a4")]; 
     [searchBar setPlaceholderFont:kFont(14)]; 
     [searchBar addTarget:self action:@selector(SearchTextFieldDidChange:) forControlEvents:UIControlEventEditingChanged]; 
     [navgationView addSubview:searchBar]; 
    } 
    @end 

    //BKSearchBar The key code 
       @implementation BKSearchBar 
       - (id)initWithFrame:(CGRect)frame 
       { 
        self = [super initWithFrame:frame]; 
        if (self) { 
         // 设置背景 
         self.backgroundColor = kcallColor(@"7d1d57"); 
         self.returnKeyType = UIReturnKeySearch; 
         // 设置内容 -- 垂直居中 
         self.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter; 
         [self UI]; 
        } 
        return self; 
       } 
    - (void)UI{ 
     // 设置左边显示一个放大镜 
     UIImageView *leftView = [[UIImageView alloc] init]; 
     omit... 
     //右边的view 
     UIImageView *rightView = [[UIImageView alloc] init]; 
     omit... 
    } 
      - (CGRect)placeholderRectForBounds:(CGRect)bounds{ 
       CGRect rect = CGRectMake(self.leftView.right, (self.height - 24)/2, bounds.size.width, 14); 
       return rect; 
      } 
      - (void)clearText{ 
       self.text = nil; 
      } 
      - (void)setPlaceholderColor:(UIColor *)color{ 
       [self setValue:color forKeyPath:@"_placeholderLabel.textColor"]; 
      } 
      - (void)setPlaceholderFont:(UIFont *)font{ 
       [self setValue:font forKeyPath:@"_placeholderLabel.font"]; 
      } 

Answer 1

は、すべての感謝の問題が解決されるため、実行時の

！！！

+ (void)swizzleInstanceMethod:(Class)class originSelector:(SEL)originSelector otherSelector:(SEL)otherSelector 
{ 
    Method otherMehtod = class_getInstanceMethod(class, otherSelector); 
    Method originMehtod = class_getInstanceMethod(class, originSelector); 
    // 交换2个方法的实现 
    method_exchangeImplementations(otherMehtod, originMehtod); 
}