WebView--UIWebView 和 WKWebView （APP与JS交互）,JS和OC 相互传值调用

一.WKWebView的使用：
参考：
http://www.360doc.com/content/15/1111/15/19119980_512349271.shtml
http://blog.csdn.net/meegomeego/article/details/47721797
1.初始化：

 WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 64, AppScreenWidth, AppScreenHeight-64) ];   
 webView.UIDelegate = self;   
 webView.navigationDelegate = self;   
 [self.view addSubview:webView];
 [webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:urlStr]]];

2.代理方法执行顺序：

（1）webView:decidePolicyForNavigationAction:decisionHandler:
（相当于 webView: shouldStartloadWithRequest:navigationType,在这个方法中做拦截，然后处理decisionHandler(WKNavigationActionPolicyAllow);
（2）webView:didStartProvisionalNavigation:
（3）webView:didCommitNavigation:
（4）webView:didFinishNavigation:

二.知识点：
1.WKWebView 从iOS8.0开始，相比于UIWebView，有更多的优势：
更多支持HTML5的特性；
官方宣称高达60fps的滚动刷新频率及内置手势；
增加加载进度的属性；
拆分成了14个类和3个协议。
极大的减少了内存的占用。

2.不仅可以加载Html页面，还支持PDF，Word，txt,及各种图片的展示。
3.收到网页中的脚本消息，

- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message;
实现这个代理方法

4.性能的分析可以参考网址文章：
性能数据跟白屏时间，页面耗时，加载链接的一些性能数据。
http://www.cnblogs.com/junhuawang/p/5759224.html

5.动态加载并运行JS

用于在客户端内部加入JS
代码，并执行，示例如下： // 图片缩放的js代码
NSString *js = @"var count = document.images.length;for (var i = 0; i < count; i++) {var image = document.images[i];image.style.width=320;};
window.alert('找到' + count + '张图');";
// 根据JS字符串初始化WKUserScript对象
WKUserScript *script = [[WKUserScript alloc] initWithSource:js injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES];
// 根据生成的WKUserScript对象，初始化
WKWebViewConfigurationWKWebViewConfiguration *config = [[WKWebViewConfiguration alloc] init];
[config.userContentController addUserScript:script];
_webView = [[WKWebView alloc] initWithFrame:self.view.bounds configuration:config];
[_webView loadHTMLString:@""baseURL:nil];
[self.view addSubview:_webView];

6、OC和JS之间相互传值方式一：
HTML端注入的对象调用示例：

 
function showtest(string){
            alert(string);
            window.webkit.messageHandlers.showAlertViewMessage.postMessage({body: string});
        }
备注：此处的showAlertViewMessage，是在OC端定义好的方法名称，对象名称。
调用.postMessage进行传值。

OC端代码：

  NSString *path = [[NSBundle mainBundle] pathForResource:@"testHtmldemo.html" ofType:nil];
    NSURL *htmlUrl = [NSURL fileURLWithPath:path];
    NSURLRequest *request = [NSURLRequest requestWithURL:htmlUrl];
    [JSObejctCmodel registerConfiguration:self.detailWebView.configuration withScriptMessageHandler:self];
    [self.detailWebView loadRequest:[NSURLRequest requestWithURL:htmlUrl]];

#import 

#import 
#import 


@protocol JavaScriptObjectcModelDelegate 

- (void)showAlertViewMessage:(NSDictionary *)dictString;

@end

@interface JSObejctCmodel : NSObject

+ (void)registerConfiguration:(WKWebViewConfiguration *)configuration withScriptMessageHandler:(id)handler;
+ (void)removeNameWithConfiguration:(WKWebViewConfiguration *)configuration;
+ (void)dealWithMessage:(WKScriptMessage *)message;

.m文件中

#import "JSObejctCmodel.h"
#import 
#import 

@implementation JSObejctCmodel

+ (void)registerConfiguration:(WKWebViewConfiguration *)configuration withScriptMessageHandler:(id)handler
{
    unsigned int count;
    Method *methods = class_copyMethodList([self class], &count);
    for (int i  = 0 ; i < count; i++) {
        Method oneMethod = methods[i];
        SEL selector = method_getName(oneMethod);
        NSString *name = [NSStringFromSelector(selector) stringByReplacingOccurrencesOfString:@":" withString:@""];
        [configuration.userContentController addScriptMessageHandler:handler name:name];
    }
}

+ (void)removeNameWithConfiguration:(WKWebViewConfiguration *)configuration
{
    unsigned int count;
    Method *methods = class_copyMethodList([self class], &count);
    for (int i = 0; i < count; i ++) {
        Method method = methods[i];
        SEL selector = method_getName(method);
        NSString *name = [NSStringFromSelector(selector) stringByReplacingOccurrencesOfString:@":" withString:@""];
        [configuration.userContentController removeScriptMessageHandlerForName:name];
    }
}

+ (void)dealWithMessage:(WKScriptMessage *)message
{
    unsigned int count;
    Method *methods = class_copyMethodList([self class], &count);
    for (int i = 0; i < count; i ++ ) {
        Method method = methods[i];
        SEL selector = method_getName(method);
        NSString *name = [NSStringFromSelector(selector) stringByReplacingOccurrencesOfString:@":" withString:@""];
        if ([message.name isEqualToString:name]) {
            JSObejctCmodel *model = [[JSObejctCmodel alloc] init];
            NSDictionary *dataDict = message.body;
            if ([model respondsToSelector:selector]) {
                [model performSelectorOnMainThread:selector withObject:dataDict waitUntilDone:NO];
            }
        }
    }
}

- (void)showAlertViewMessage:(NSDictionary *)dictString
{
    NSLog(@"测试数据:%@",dictString[@"body"]);
    UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"JS调用OC" message:dictString[@"body"] delegate:self cancelButtonTitle:@"ok" otherButtonTitles:nil, nil];
    [alert show];
}

控制器当中的代理方法：

@interface LoadWebController ()

- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message
{
    [JSObejctCmodel dealWithMessage:message];
}