ios 一些简单的 方法

从window中取得当前的活动的viewController

+ (UIViewController*)currentViewController:(UIWindow *)window {
    // 固定路径MenuViewController->UINavigationController->lastObject
    UIViewController *rootViewController=(UIViewController *)window.rootViewController;
    @try {
        UINavigationController *navigationController=[rootViewController childViewControllers][0];
        return [navigationController.viewControllers lastObject];
    }
    @catch (NSException *exception) {
        return rootViewController;
    }
}

返回指定的ViewController

for(UIViewController *viewController in self.navigationController.viewControllers) {

        if ([viewController isKindOfClass:[ProductDetailViewController class]]) {
            ProductDetailViewController *foundationViewController = (ProductDetailViewController *)viewController;
            [self.navigationController popToViewController:foundationViewController animated:YES];
            break;
        }else if ([viewController isKindOfClass:[SettingViewController class]]){
            SettingViewController *settingViewCOntroller=(SettingViewController *)viewController;
            [self.navigationController popToViewController:settingViewCOntroller animated:YES];
            break;
        }else{
            [self.navigationController popViewControllerAnimated:YES];
    }
    }  
//或者另一种
NSArray *viewControllers=self.navigationController.viewControllers;
     [self.navigationController popToViewController:[viewControllers objectAtIndex:viewControllers.count-2] animated:YES];

网络请求URL 转码

- (NSString *)urlEncode:(NSString *)str {
return (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef)str, NULL, CFSTR("!*'();:@&=+$,/?%#[]"), kCFStringEncodingUTF8));
}

**ios webView 获取webview 的内容高度的方法
**

int hight = [[webView stringByEvaluatingJavaScriptFromString:@"document.body.clientHeight"] intValue];

**这个方法写在webViewDidFinishLoad方法里面就可以实现获取webview 的高度
另外推荐一个webview 加载loading 动画的库**

NJKWebViewProgress库
https://github.com/songbai1211/NJKWebViewProgress
关于webview一些方法介绍
http://blog.csdn.net/alincexiaohao/article/details/42458663