如何从子类委托方法调用超类委托方法

Question

我有一个 SuperClass 实现了 <UIWebViewDelegate>，在这个 class 我实现了方法 webView:shouldStartLoadWithRequest:navigationType:

@interface SuperClass
...
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request1 navigationType:(UIWebViewNavigationType)navigationType {
     // SuperClass treatment
}
...
@end

然后我有一个 SubClass 扩展这个 SuperClass。 SubClass 也实现了 <UIWebViewDelegate>，方法 webView:shouldStartLoadWithRequest:navigationType: 也实现了 :

@interface SubClass: SuperClass
...
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request1 navigationType:(UIWebViewNavigationType)navigationType {
     // SubClass treatment
}
...
@end

该代码对我有用，因为我需要对 SubClass 进行特定处理。但是在特定情况下，我需要调用 SuperClass webView:shouldStartLoadWithRequest:navigationType: 方法。

我需要委托来执行 SuperClass UIWebViewDelegate 方法。

我尝试使用super调用SuperClass方法，但是没有用！

这可能吗？

Answer 1

@interface SuperClass
- (void)handleWebViewShouldStartLoadWithRequest:(NSURLRequest *)request;

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
     [self handleWebViewShouldStartLoadWithRequest:request];
}

@end

在子类handleWebViewShouldStartLoadWithRequest:中，可以调用[super handleWebViewShouldStartLoadWithRequest:request];

Answer 2

超级班

@interface ViewController () <UIWebViewDelegate>
@end

@implementation ViewController

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request1 navigationType:(UIWebViewNavigationType)navigationType 
{    
  NSLog(@"superview");
  return true;    
}

子类 (ViewController1.m)

@interface ViewController1 () <UIWebViewDelegate>
    
@property (strong, nonatomic) IBOutlet UIWebView *webview;

@end

@implementation ViewController1

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request1 navigationType:(UIWebViewNavigationType)navigationType {

     NSLog(@"subclass");
     [super webView:webView shouldStartLoadWithRequest:request1 navigationType:navigationType];
     return true;

 }

- (IBAction)action:(id)sender {

    NSLog(@"loading");
    [_webview loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.google.co.in"]]];

 }

在日志中显示为：

2016-06-29 17:51:39.807 Test[31575:8224563] loading

2016-06-29 17:51:41.008 Test[31575:8224563] subclass

2016-06-29 17:51:41.008 Test[31575:8224563] superview

如何从子类委托方法调用超类委托方法

How to call SuperClass delegate method from SubClass delegate method

delegates

objective-c

uiwebview

ios