iOS WebView Post传参用法（注意URLEncoding编码）
UIWebView用法
post请求传参数
UIWebView *webView = [[UIWebView alloc] initWithFrame:[UIScreen mainScreen].bounds];
// 将UIWebView添加到当前View
[self.view addSubview:webView];
// 设置访问的URL
NSURL *url = [NSURL URLWithString:@"http://www.example.com"];
NSURL *url = [NSURL URLWithString: @"需要填写自己的URL"];
NSString *body = [NSString stringWithFormat: @"arg1=%@&arg2=%@", @"val1",@"val2"]; NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL: url];
body = [body stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet characterSetWithCharactersInString:@"#%<>[\]^`{|}"]+"].invertedSet];//切记要注意urlEnding编码 这个是坑啊
[request setHTTPMethod: @"POST"];
[request setHTTPBody: [body dataUsingEncoding: NSUTF8StringEncoding]];
[webView loadRequest: request];
WebView UrlEncoding陈年老坑

WKWebview post请求提交参数 存在参数不能提交的问题 附上解决问题链接
WKWebview代理方法
/* 1.在发送请求之前，决定是否跳转 */

• (void)webView:(WKWebView *)webView
  decidePolicyForNavigationAction:(WKNavigationAction )navigationAction
  decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler;
  / 2.页面开始加载 */
• (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation )navigation;
  / 3.在收到服务器的响应头，根据response相关信息，决定是否跳转。 */
• (void)webView:(WKWebView *)webView
  decidePolicyForNavigationResponse:(WKNavigationResponse )navigationResponse
  decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler;
  / 4.开始获取到网页内容时返回，需要注入JS，在这里添加 */
• (void)webView:(WKWebView *)webView didCommitNavigation:(WKNavigation )navigation;
  / 5.页面加载完成之后调用 */
• (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation )navigation;
  / error - 页面加载失败时调用 */
• (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation )navigation;
  / 其他 - 处理服务器重定向Redirect */
• (void)webView:(WKWebView *)webView
  didReceiveServerRedirectForProvisionalNavigation:(WKNavigation *)navigation;