ZHWebView

为了解决UIWebView系统占用内存过大的问题，苹果官方新出了WebKit框架。WKWebView在性能方面比UIWebView好多，并且WKWebView可以通过KVO监听网页加载的进度。然而WKWeView也有缺陷，就是不支持离线缓存。

ZHWebView是为了兼容iOS7,是对UIWebView和WKWebView的封装。在iOS8以上的系统会自动选择WKWebView，API的设计参考UIWebView的API。使用前需要导入WebKit和JavaScriptCore框架

新特性：

• 添加加载进度的显示
• 根据系统版本选择UIWebView或者WKWebView
• 添加WebView与JS的交互

UIWebView与js的交互

设置步骤

1. ZHWebView.h文件中的JSExportDelegate定义JS调用OC的方法。
2. 在控制器或者其他对象实现JSExportDelegate协议方法
3. 设置交互对象view.JSExportObject = self;

注意点:

当js调用OC的方法中有多个参数值，html中定义的方法为OC的方法实用驼峰命名拼接起来。

例如:

//JSExportDelegate中定义
- (void)showAlert:(NSString *)title msg:(NSString *)msg;

//html中的调用
mycs.showAlertMsg('js title', 'js message')

WKWebView与js交互

只需要在代理中实现一下方法就可以

- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message;

部分API

#import <UIKit/UIKit.h>
#import <WebKit/WebKit.h>
#import <JavaScriptCore/JavaScriptCore.h>

@protocol ZHWebViewDelegate <NSObject>

@optional
- (BOOL)ZHWebView:(UIView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType;

- (void)ZHWebViewDidStartLoad:(UIView *)webView;

- (void)ZHWebViewDidFinishLoad:(UIView *)webView;

- (void)ZHWebView:(UIView *)webView didFailLoadWithError:(NSError *)error;

//WKWebView中JS调用OC代码
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message;

//iOS8以后需要实现,否则不会弹窗
@required
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler ;

- (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL))completionHandler;

- (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString *))completionHandler;

@end

//UIWebView中JS调用OC方法
@protocol JSExportDelegate <JSExport>

@required
- (void)callSystemCamera;
// 在JS中调用时，函数名应该为showAlertMsg(arg1, arg2)
- (void)showAlert:(NSString *)title msg:(NSString *)msg;
// 通过JSON传过来
- (void)callWithDict:(NSDictionary *)params;
// JS调用Oc，然后在OC中通过调用JS方法来传值给JS。
- (void)jsCallObjcAndObjcCallJsWithDict:(NSDictionary *)params;

@end

@interface ZHWebView : UIView

@property (nonatomic,assign) BOOL iOS8_OR_LATER;

@property (nonatomic,strong) UIView *webView;

@property (nonatomic,weak) id<ZHWebViewDelegate> delegate;

//是否显示加载进度条-》默认NO
@property (nonatomic,assign) BOOL shouldShowProgressView;
//进度条的颜色->默认是orange
@property (nonatomic,strong) UIColor *progressColor;

//UIWebView与JS交互的对象
@property (nonatomic,strong) id<JSExportDelegate> JSExportObject;

@property (nonatomic, readonly, strong) UIScrollView *scrollView;

- (void)loadRequest:(NSURLRequest *)request;
- (void)loadHTMLString:(NSString *)string baseURL:(NSURL *)baseURL;
- (void)loadData:(NSData *)data MIMEType:(NSString *)MIMEType textEncodingName:(NSString *)textEncodingName baseURL:(NSURL *)baseURL;

@property (nonatomic, readonly, strong) NSURLRequest *request;

- (void)reload;
- (void)stopLoading;

- (void)goBack;
- (void)goForward;

@property (nonatomic, readonly, getter=canGoBack) BOOL canGoBack;
@property (nonatomic, readonly, getter=canGoForward) BOOL canGoForward;
@property (nonatomic, readonly, getter=isLoading) BOOL loading;

- (void)evaluatingJavaScriptFromString:(NSString *)js completionHandler:(void (^)(id, NSError *))completionHandler;

@property (nonatomic) BOOL scalesPageToFit;

@end



@property (nonatomic) BOOL scalesPageToFit;

@end