IOS - UIWebView隐藏工具条

最近研究富文本编辑器的web版实现时，发现输入键盘上的工具条隐藏不掉，试过了很多的方法，也无法实现。
后来在一个富文本项目中，找到了解决的方案。

.h文件

#import <UIKit/UIKit.h>
#import <objc/runtime.h>

@interface UIWebView (Ext)

@property (nonatomic, assign) BOOL hidesInputAccessoryView;

@end

.m文件

#import "UIWebView+Ext.h"

@implementation UIWebView (Ext)


static const char * const hackishFixClassName = "UIWebBrowserViewMinusAccessoryView";
static Class hackishFixClass = Nil;

- (UIView *)hackishlyFoundBrowserView {
    UIScrollView *scrollView = self.scrollView;
    
    UIView *browserView = nil;
    for (UIView *subview in scrollView.subviews) {
        if ([NSStringFromClass([subview class]) hasPrefix:@"UIWebBrowserView"]) {
            browserView = subview;
            break;
        }
    }
    return browserView;
}

- (id)methodReturningNil {
    return nil;
}

- (void)ensureHackishSubclassExistsOfBrowserViewClass:(Class)browserViewClass {
    if (!hackishFixClass) {
        Class newClass = objc_allocateClassPair(browserViewClass, hackishFixClassName, 0);
        newClass = objc_allocateClassPair(browserViewClass, hackishFixClassName, 0);
        IMP nilImp = [self methodForSelector:@selector(methodReturningNil)];
        class_addMethod(newClass, @selector(inputAccessoryView), nilImp, "@@:");
        objc_registerClassPair(newClass);
        
        hackishFixClass = newClass;
    }
}

- (BOOL) hidesInputAccessoryView {
    UIView *browserView = [self hackishlyFoundBrowserView];
    return [browserView class] == hackishFixClass;
}

- (void) setHidesInputAccessoryView:(BOOL)value {
    UIView *browserView = [self hackishlyFoundBrowserView];
    if (browserView == nil) {
        return;
    }
    [self ensureHackishSubclassExistsOfBrowserViewClass:[browserView class]];
    
    if (value) {
        object_setClass(browserView, hackishFixClass);
    }
    else {
        Class normalClass = objc_getClass("UIWebBrowserView");
        object_setClass(browserView, normalClass);
    }
    [browserView reloadInputViews];
}

@end