fix issue

@@ -21,7 +21,7 @@
 @property (nonatomic) BOOL enableProgressBar;
 
 @property (weak, nonatomic) UIView * currentNaviBar;
-- (UIView *)webView;
+- (WKWebView *)webView;
 
 - (instancetype)initWithFrame:(CGRect)frame withNaviBar:(UIView *)naviBar;
 /**

@@ -131,7 +131,7 @@
     return _webViewController;
 }
 
-- (UIView *)webView
+- (WKWebView *)webView
 {
     return self.webViewController.webView;
 }