iOS【动态修改第三方类方法】

#import "WKWebViewJavascriptBridge+ReplaceMethod.h"

@implementation WKWebViewJavascriptBridge (ReplaceMethod)

- (void)webView:(WKWebView *)webView
decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction
decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    
    
    WKWebView *tempWeb;
    id<WKNavigationDelegate> _tempWebViewDelegate;
    WebViewJavascriptBridgeBase *_tempBase;
    
    unsigned int count = 0;
    Ivar *ivar = class_copyIvarList([self class], &count);
    for (int i = 0; i<count; i++) {
        Ivar var = ivar[i];
        const char *varName = ivar_getName(var);
        NSString *proname = [NSString stringWithUTF8String:varName];
        
//        NSLog(@"-----web:   %@",proname);
//        const char * name = ivar_getName(var);
//        const char * type = ivar_getTypeEncoding(var);
//        NSLog(@"-----web 类型为 %s 的 %s ",type, name);
        
        
        if ([proname isEqualToString:@"_webView"]) {
            tempWeb = object_getIvar(self, var);
        } else if([proname isEqualToString:@"_webViewDelegate"]) {
            _tempWebViewDelegate = object_getIvar(self, var);
        } else if([proname isEqualToString:@"_base"]) {
            _tempBase = object_getIvar(self, var);
        }
        
    }

    if(tempWeb != webView && tempWeb) {
        return;
    }
    
    NSURL *url = navigationAction.request.URL;
    __strong typeof(_tempWebViewDelegate) strongDelegate = _tempWebViewDelegate;
    
    if ([_tempBase isCorrectProcotocolScheme:url]) {
        
        if ([_tempBase isCorrectProcotocolScheme:url]) {
            if ([_tempBase isBridgeLoadedURL:url]) {
                [_tempBase injectJavascriptFile];
            } else if ([_tempBase isQueueMessageURL:url]) {
                
                if (class_respondsToSelector([self class],@selector(WKFlushMessageQueue))) {
                    [self performSelector:@selector(WKFlushMessageQueue)];
                }
            } else {
                [_tempBase logUnkownMessage:url];
            }
            decisionHandler(WKNavigationActionPolicyCancel);
            
            return;//添加此句解决三方库里的崩溃
        }
    }
    
    if (strongDelegate && [strongDelegate respondsToSelector:@selector(webView:decidePolicyForNavigationAction:decisionHandler:)]) {
        [_tempWebViewDelegate webView:webView decidePolicyForNavigationAction:navigationAction decisionHandler:decisionHandler];
    } else {
        decisionHandler(WKNavigationActionPolicyAllow);
    }
    
}
@end