iOS用WKWebView与JS交互获取系统图片及WKWebView的Alert,Confirm,TextInput的监听代理方法使用，屏蔽WebView的可选菜单

本文链接：https://blog.youkuaiyun.com/Boyqicheng/article/details/52812968

最近做一个项目，开始是使用WebView与JS交互的，由于内存管理方面WebView欠佳。WKWebVIew的内存线程管理好，所以选择使用 WKWebVIew(使用WKWebView 的缺点在于，这个控件加载的H5页面不支持ajax请求，所以需要自己把网络请求在OC上实现)。

一、首先说下应该注意的问题：

1.要获取拍照或相册的图片，如果是iOS 10系统，需要设置访问权限（在 Info-plist 中设置）

相机权限： Privacy - Camera Usage Description 是否允许此App使用你的相机？
相册权限： Privacy - Photo Library Usage Description 是否允许此App访问你的媒体资料库？

2.WebView和WKWebView和JS互调的方法和使用的传参类型不同

WebView 使用（window.iosModel.getImage(JSON.stringify(parameter)); //JSON.stringify(参数字符串) 这个方法是把字符串转换成json字符串 parameter是参数字符串
）传值给 OC

WKWebView 使用（window.webkit.messageHandlers.iosModel.postMessage(parameter)）

3.需要特别注意的是：WKWebView 不执行JS写的 ajax请求（WKWebView 可能由于基于 WebKit，并不会执行 C socket 相关的函数对 HTTP 请求进行处理）如果有网络请求，需要自己用OC实现

4.使用的时候不要忘记挂上使用到的代理，和导入代理

@interface ViewController () <WKScriptMessageHandler, WKNavigationDelegate, WKUIDelegate,UINavigationControllerDelegate,UIImagePickerControllerDelegate>

5.屏蔽WebView的可选菜单（即不会出现拷贝、全选等弹出菜单）在加载完成后的代理中执行以下两段JS

// 导航完成时，会回调（也就是页面载入完成了）
- (void)webView:(WKWebView *)webView didFinishNavigation:(null_unspecified WKNavigation *)navigation {
    NSLog(@"66===%s", __FUNCTION__);
    // 禁用选中效果
    [self.webView evaluateJavaScript:@"document.documentElement.style.webkitUserSelect='none'" completionHandler:nil];
    [self.webView evaluateJavaScript:@"document.documentElement.style.webkitTouchCallout='none'" completionHandler:nil];
}

二、代码：

<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<div>
            <h3>JS与iOS交互</h3>
            <h4>JS页面获取iOS系统图片</h5>
        </div>
		<div>
			<input type = "button" style="width: 50%;height: 5%;" id="Button" value="打开相机获取图片" onclick="getIOSImage()"></button>
		</div><dir />
		<div>
			<img src="testImage.png" id="changeImage"style="width: 30%; height: 30%;" onclick="getIOSImage()"><!--src="图片的相对路径" 如果把html文件导入工程中，图片路径和OC一样只写图片名字和后缀就可以，（记得要先把图片添加到工程） 图片也可以实现按钮的方法getIOSImage -->
		</div>
        <span id="iosParame" style="width: 200px; height: 50%; color:orangered; font-size:15px" value="等待获取ios参数" >
            </div>
		<script>
			var getIOSImage = function(){
				var parameter = {'title':'JS调OC','describe':'这里就是JS传给OC的参数'};
				// 在下面这里实现js 调用系统原生api iosDelegate
                //JSON.stringify(参数字符串) 这个方法是 把字符串转换成json字符串
	window.iosDelegate.getImage(JSON.stringify(parameter));// 实现数据的 json 格式字符串
			}
        // 这里是 iOS调用js的方法
        function setImageWithPath(arguments){
            document.getElementById('changeImage').src = arguments['imagePath'];
            document.getElementById('iosParame').innerHTML = arguments['iosContent'];
        }
		</script>
	</body>
</html>

<pre name="code" class="objc">#import "ViewController.h"
#import <JavaScriptCore/JavaScriptCore.h>
#import <WebKit/WebKit.h>
#import "SaveImage_Util.h"

@interface ViewController () <WKScriptMessageHandler, WKNavigationDelegate, WKUIDelegate,UINavigationControllerDelegate,UIImagePickerControllerDelegate>

@property (nonatomic, strong) WKWebView *webView;
@property (nonatomic, strong) UIProgressView *progressView;

@end

@implementation ViewController
{
    int indextNumb;// 交替图片名字
    UIImage *getImage;//获取的图片
}
- (void)viewDidLoad {
  [super viewDidLoad];
  
  self.edgesForExtendedLayout = UIRectEdgeNone;
  self.automaticallyAdjustsScrollViewInsets = NO;
  
  WKWebViewConfiguration *config = [[WKWebViewConfiguration alloc] init];
  // 设置偏好设置
  config.preferences = [[WKPreferences alloc] init];
  // 默认为0
  config.preferences.minimumFontSize = 10;
  // 默认认为YES
  config.preferences.javaScriptEnabled = YES;
  // 在iOS上默认为NO，表示不能自动通过窗口打开
  config.preferences.javaScriptCanOpenWindowsAutomatically = NO;


  // web内容处理池
  config.processPool = [[WKProcessPool alloc] init];

  // 通过JS与webview内容交互
  config.userContentController = [[WKUserContentController alloc] init];
  // 注入JS对象名称AppModel，当JS通过AppModel来调用时，
  // 我们可以在WKScriptMessageHandler代理中接收到
  [config.userContentController addScriptMessageHandler:self name:@"iosModel"];



        //通过默认的构造器来创建对象
  self.webView = [[WKWebView alloc] initWithFrame:self.view.bounds configuration:config];
    // 导航代理
    self.webView.navigationDelegate = self;
    // 与webview UI交互代理
    self.webView.UIDelegate = self;
  NSURL *path = [[NSBundle mainBundle] URLForResource:@"testJS" withExtension:@"html"];
  [self.webView loadRequest:[NSURLRequest requestWithURL:path]];
  [self.view addSubview:self.webView];
  
  

  // 添加KVO监听
  [self.webView addObserver:self
                 forKeyPath:@"loading"
                    options:NSKeyValueObservingOptionNew
                    context:nil];
  [self.webView addObserver:self
                 forKeyPath:@"title"
                    options:NSKeyValueObservingOptionNew
                    context:nil];
  [self.webView addObserver:self
                 forKeyPath:@"estimatedProgress"
                    options:NSKeyValueObservingOptionNew
                    context:nil];

  // 添加进入条
  self.progressView = [[UIProgressView alloc] init];
  self.progressView.frame = self.view.bounds;
  [self.view addSubview:self.progressView];
  self.progressView.backgroundColor = [UIColor blackColor];
  
  self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"后退" style:UIBarButtonItemStyleDone target:self action:@selector(goback)];
  self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"前进" style:UIBarButtonItemStyleDone target:self action:@selector(gofarward)];
}

- (void)goback {
  if ([self.webView canGoBack]) {
    [self.webView goBack];
  }
}

- (void)gofarward {
  if ([self.webView canGoForward]) {
    [self.webView goForward];
  }
}

#pragma mark - WKScriptMessageHandler
// 通过这个方法获取 JS传来的json字符串
- (void)userContentController:(WKUserContentController *)userContentController
      didReceiveScriptMessage:(WKScriptMessage *)message
{
  if ([message.name isEqualToString:@"iosModel"]) {
    // 打印所传过来的参数，只支持NSNumber, NSString, NSDate, NSArray,
    // NSDictionary, and NSNull类型
      NSLog(@"JS传来的json字符串 ：  %@", message.body);
      NSDictionary *jsDictionary = message.body;
      if ([jsDictionary[@"means"] isEqualToString:@"获取系统图片"])
      {
          [self beginOpenPhoto];
      }
  }
}

#pragma mark - KVO
- (void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object
                        change:(NSDictionary<NSString *,id> *)change
                       context:(void *)context {
  if ([keyPath isEqualToString:@"loading"]) {
    NSLog(@"loading");
  } else if ([keyPath isEqualToString:@"title"]) {
    self.title = self.webView.title;
  } else if ([keyPath isEqualToString:@"estimatedProgress"]) {
    NSLog(@"progress: %f", self.webView.estimatedProgress);
    self.progressView.progress = self.webView.estimatedProgress;
  }
  if (!self.webView.loading) {
    [UIView animateWithDuration:0.5 animations:^{
      self.progressView.alpha = 0;
    }];
  }
}

#pragma mark - WKNavigationDelegate
    // 请求开始前，会先调用此代理方法
    // 与UIWebView的
    // - (BOOL)webView:(UIWebView *)webView
    // shouldStartLoadWithRequest:(NSURLRequest *)request
    // navigationType:(UIWebViewNavigationType)navigationType;
    // 类型，在请求先判断能不能跳转（请求）

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:
(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
  NSString *hostname = navigationAction.request.URL.host.lowercaseString;
  if (navigationAction.navigationType == WKNavigationTypeLinkActivated
      && ![hostname containsString:@".lanou.com"]) {
// 对于跨域，需要手动跳转， 用系统浏览器（Safari）打开
    [[UIApplication sharedApplication] openURL:navigationAction.request.URL];
    
    // 不允许web内跳转
    decisionHandler(WKNavigationActionPolicyCancel);
  } else {
    self.progressView.alpha = 1.0;
    decisionHandler(WKNavigationActionPolicyAllow);
  }
  
}


    // 在响应完成时，会回调此方法
    // 如果设置为不允许响应，web内容就不会传过来
- (void)webView:(WKWebView *)webView
decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse
decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler {
  decisionHandler(WKNavigationResponsePolicyAllow);
  
}


// 开始导航跳转时会回调
- (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(null_unspecified WKNavigation *)navigation {
   
}

    // 接收到重定向时会回调
- (void)webView:(WKWebView *)webView
didReceiveServerRedirectForProvisionalNavigation:(null_unspecified WKNavigation *)navigation {
   
}


    // 导航失败时会回调
- (void)webView:(WKWebView *)webView
didFailProvisionalNavigation:(null_unspecified WKNavigation *)navigation withError:(NSError *)error {
    
}


// 页面内容到达main frame时回调
- (void)webView:(WKWebView *)webView didCommitNavigation:(null_unspecified WKNavigation *)navigation {
    
}

// 导航完成时，会回调（也就是页面载入完成了）
- (void)webView:(WKWebView *)webView didFinishNavigation:(null_unspecified WKNavigation *)navigation {
    NSLog(@"66===%s", __FUNCTION__);
    // 禁用选中效果
    [self.webView evaluateJavaScript:@"document.documentElement.style.webkitUserSelect='none'" completionHandler:nil];
    [self.webView evaluateJavaScript:@"document.documentElement.style.webkitTouchCallout='none'" completionHandler:nil];
}
    // 导航失败时会回调
- (void)webView:(WKWebView *)webView didFailNavigation:
(null_unspecified WKNavigation *)navigation withError:(NSError *)error
{
    
}


/* 对于HTTPS的都会触发此代理，如果不要求验证，传默认就行
    如果需要证书验证，与使用AFN进行HTTPS证书验证是一样的 */

- (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:
(NSURLAuthenticationChallenge *)challenge completionHandler:
(void (^)(NSURLSessionAuthChallengeDisposition disposition,
          NSURLCredential *__nullable credential))completionHandler
{
  completionHandler(NSURLSessionAuthChallengePerformDefaultHandling, nil);
}


// 9.0才能使用，web内容处理中断时会触发
/*
- (void)webViewWebContentProcessDidTerminate:(WKWebView *)webView {
}
*/
#pragma mark - WKUIDelegate
- (void)webViewDidClose:(WKWebView *)webView {
    
}
/* 在JS端调用alert函数时，会触发此代理方法。JS端调用alert时所传的数据可以通过message拿到 在原生得到结果后，需要回调JS，是通过completionHandler回调 */
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message
initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler
{
  UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"alert" message:message preferredStyle:UIAlertControllerStyleAlert];
  [alert addAction:[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
    completionHandler();
  }]];
  
  [self presentViewController:alert animated:YES completion:NULL];
  NSLog(@"%@", message);
 
}

    // JS端调用confirm函数时，会触发此方法
    // 通过message可以拿到JS端所传的数据
    // 在iOS端显示原生alert得到YES/NO后
    // 通过completionHandler回调给JS端
- (void)webView:(WKWebView *)webView
runJavaScriptConfirmPanelWithMessage:(NSString *)message
initiatedByFrame:(WKFrameInfo *)frame
completionHandler:(void (^)(BOOL result))completionHandler {
  UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"confirm" message:message preferredStyle:UIAlertControllerStyleAlert];
  [alert addAction:[UIAlertAction actionWithTitle:@"确定"
    style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action){
    completionHandler(YES);
  }]];
  [alert addAction:[UIAlertAction actionWithTitle:@"取消"
  style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action)
    {
    completionHandler(NO);
  }]];
  [self presentViewController:alert animated:YES completion:NULL];
  NSLog(@"%@", message);
}
 // JS端调用prompt函数时，会触发此方法
    // 要求输入一段文本
    // 在原生输入得到文本内容后，通过completionHandler回调给JS
- (void)webView:(WKWebView *)webView
runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt
    defaultText:(nullable NSString *)defaultText
initiatedByFrame:(WKFrameInfo *)frame
completionHandler:(void (^)(NSString * __nullable result))completionHandler
{
  UIAlertController *alert = [UIAlertController alertControllerWithTitle:prompt message:defaultText preferredStyle:UIAlertControllerStyleAlert];
  [alert addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {
    textField.textColor = [UIColor redColor];
  }];
  [alert addAction:[UIAlertAction actionWithTitle:@"确定"
    style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
    completionHandler([[alert.textFields lastObject] text]);
  }]];
  
  [self presentViewController:alert animated:YES completion:NULL];
}

//  获取图片
- (void)beginOpenPhoto
{
    // 主队列 异步打开相机
    dispatch_async(dispatch_get_main_queue(), ^{
        [self takePhoto];
    });
}
#pragma mark 取消选择照片代理方法
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [picker dismissViewControllerAnimated:YES completion:nil];
}
#pragma mark      //打开本地照片
- (void) localPhoto
{
    UIImagePickerController *imagePicker = [[UIImagePickerController alloc]init];
    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    imagePicker.delegate = self;
    [self presentViewController:imagePicker animated:YES completion:nil];
}
#pragma mark      //打开相机拍照
- (void) takePhoto
{
    UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypeCamera;
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    {
        UIImagePickerController *picker = [[UIImagePickerController alloc]init];
        picker.delegate = self;
        picker.allowsEditing = YES;
        picker.sourceType = sourceType;
        picker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
        [self presentViewController:picker animated:YES completion:nil];
    }
    else
    {
        NSLog(@"模拟器中不能打开相机");
        [self localPhoto];
    }
}
//  选择一张照片后进入这里
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
    NSString *type = [info objectForKey:UIImagePickerControllerMediaType];
    //  当前选择的类型是照片
    if ([type isEqualToString:@"public.image"])
    {
        // 获取照片
        getImage = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
        NSLog(@"===Decoded image size: %@", NSStringFromCGSize(getImage.size));
        // obtainImage 压缩图片 返回原尺寸
        indextNumb = indextNumb == 1?2:1;
        NSString *nameStr = [NSString stringWithFormat:@"Varify%d.jpg",indextNumb];
        [SaveImage_Util saveImage:getImage ImageName:nameStr back:^(NSString *imagePath) {
            dispatch_async(dispatch_get_main_queue(), ^{
                NSLog(@"图片路径：%@",imagePath);
                /**
                 *  这里是IOS 调 js 其中 setImageWithPath 就是js中的方法 setImageWithPath(),参数是字典
                 */
                NSString *callJSString = [NSString stringWithFormat:@"%@({\"imagePath\":\"%@\",\"iosContent\":\"获取图片成功，把系统获取的图片路径传给js 让html显示\"})",@"setImageWithPath",imagePath];
                [self.webView evaluateJavaScript:callJSString completionHandler:^(id resultObject, NSError * _Nullable error) {
                    if (!error)
                    {
                        NSLog(@"OC调 JS成功");
                    }
                    else
                    {
                        NSLog(@"OC调 JS 失败");
                    }
                }];
            });
        }];
        [picker dismissViewControllerAnimated:YES completion:nil];
    }
}

@end

下面是图片处理的工具类

//  SaveImage_Util.h
//  JS和iOS交互
//
//  Created by user on 16/10/14.
//  Copyright © 2016年 user. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
@interface SaveImage_Util : NSObject
#pragma mark  保存图片到document
+ (BOOL)saveImage:(UIImage *)saveImage ImageName:(NSString *)imageName back:(void(^)(NSString *imagePath))back;

@end

//  SaveImage_Util.m
//  JS和iOS交互
//
//  Created by user on 16/10/14.
//  Copyright © 2016年 user. All rights reserved.
//

#import "SaveImage_Util.h"

@implementation SaveImage_Util
#pragma mark  保存图片到document
+ (BOOL)saveImage:(UIImage *)saveImage ImageName:(NSString *)imageName back:(void(^)(NSString *imagePath))back
{
    NSString *path = [SaveImage_Util getImageDocumentFolderPath];
    NSData *imageData = UIImagePNGRepresentation(saveImage);
    NSString *documentsDirectory = [NSString stringWithFormat:@"%@/", path];
    // Now we get the full path to the file
    NSString *imageFile = [documentsDirectory stringByAppendingPathComponent:imageName];
    // and then we write it out
    NSFileManager *fileManager = [NSFileManager defaultManager];
    //如果文件路径存在的话
    BOOL bRet = [fileManager fileExistsAtPath:imageFile];
    if (bRet)
    {
        //        NSLog(@"文件已存在");
        if ([fileManager removeItemAtPath:imageFile error:nil])
        {
            //            NSLog(@"删除文件成功");
            if ([imageData writeToFile:imageFile atomically:YES])
            {
                //                NSLog(@"保存文件成功");
                back(imageFile);
            }
        }
        else
        {
            
        }
        
    }
    else
    {
        if (![imageData writeToFile:imageFile atomically:NO])
        {
            [fileManager createDirectoryAtPath:documentsDirectory withIntermediateDirectories:YES attributes:nil error:nil];
            if ([imageData writeToFile:imageFile atomically:YES])
            {
                back(imageFile);
            }
        }
        else
        {
            return YES;
        }
        
    }
    return NO;
}
#pragma mark  从文档目录下获取Documents路径
+ (NSString *)getImageDocumentFolderPath
{
    NSString *patchDocument = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
    return [NSString stringWithFormat:@"%@/Images", patchDocument];
}
@end

以上内容仅供参考，部分内容来之网络，如有重复，请联系修改，谢谢！

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