iOS:在OC中调用JS脚本

示例一：在webView中调用js脚本进行搜索

1.首先导入JavaScriptCore.framework这个框架

2.创建webView、设置代理、请求手机端百度

#import "ViewController.h"
#import <JavaScriptCore/JavaScriptCore.h>

#define SCREEN_WIDTH [UIScreen mainScreen].bounds.size.width
#define SCREEN_HEIGHT [UIScreen mainScreen].bounds.size.height

@interface ViewController ()<UIWebViewDelegate> @property (strong,nonatomic)UIWebView *webView; @property (assign,nonatomic)BOOL isFirstLoadWeb; @end

@implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; self.webView = [[UIWebView alloc]initWithFrame:self.view.bounds]; self.webView.scalesPageToFit = YES; self.webView.backgroundColor = [UIColor clearColor]; self.webView.delegate = self; [self.view addSubview:self.webView]; NSURL *URL = [NSURL URLWithString:@"http://m.baidu.com"]; NSURLRequest *request = [[NSURLRequest alloc]initWithURL:URL]; [self.webView loadRequest:request]; }

3.通过代理方法,在里面调用自定义的JS脚本

-(void)webViewDidFinishLoad:(UIWebView *)webView{ //程序会一直调用该方法,所以判断若是第一次加载后使用我们自定义的js,此后不再调用JS,否则会出现网页抖动现象
    if (!_isFirstLoadWeb) { _isFirstLoadWeb = YES; //获取当前页面的url
        NSString *url = [webView  stringByEvaluatingJavaScriptFromString:@"document.location.href"]; //获取页面的title
        NSString *title = [webView stringByEvaluatingJavaScriptFromString:@"document.title"]; NSLog(@"%@----%@",url,title); //给webView添加一个自定义的JavaScript
        [webView stringByEvaluatingJavaScriptFromString:@"var script = document.createElement('script');"
            "script.type = 'text/javascript';"
            "script.text = \"function myFuncation(){"
            "var field = document.getElementsByName('word')[0];"
            "field.value = '夏先森的博客园';"
            "document.forms[0].submit();"
         "}\";"
         "document.getElementsByTagName('head')[0].appendChild(script);"]; //开始调用自定义的JavaScript
        [webView stringByEvaluatingJavaScriptFromString:@"myFuncation();"]; }else{ return; } } @end

演示截图如下：

2016-04-18 21:37:24.670 OC调用JS[7568:356964] https://m.baidu.com/----百度一下

  

 

 

示例二：通过滑动条动态改变网页中字体的大小

1.首先导入JavaScriptCore.framework这个框架

2.创建webView、设置代理、请求手机端百度

#import "ViewController.h"
#import <JavaScriptCore/JavaScriptCore.h>

#define SCREEN_WIDTH [UIScreen mainScreen].bounds.size.width
#define SCREEN_HEIGHT [UIScreen mainScreen].bounds.size.height

@interface ViewController ()<UIWebViewDelegate> @property (strong,nonatomic)UIWebView *webView; @property (strong,nonatomic)UIActivityIndicatorView *activityIndicator; @property (strong,nonatomic)UISlider *slider; @end

@implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; //1.创建slider
    _slider = [[UISlider alloc]initWithFrame:CGRectMake(10, 40, SCREEN_WIDTH-20, 20)]; [_slider addTarget:self action:@selector(SliderChanged) forControlEvents:UIControlEventValueChanged]; _slider.maximumValue = 1000.0f; _slider.minimumValue = 10.0f; _slider.value = 10.0f; [self.view addSubview:_slider]; //2.创建webView
    self.webView = [[UIWebView alloc]initWithFrame:CGRectMake(0, 80, SCREEN_WIDTH, SCREEN_HEIGHT-80)]; self.webView.scalesPageToFit = YES; self.webView.backgroundColor = [UIColor clearColor]; self.webView.delegate = self; [self.view addSubview:self.webView]; NSURL *URL = [NSURL URLWithString:@"http://m.baidu.com"]; NSURLRequest *request = [[NSURLRequest alloc]initWithURL:URL]; [self.webView loadRequest:request]; //3.创建活动指示器
    _activityIndicator = [[UIActivityIndicatorView alloc]initWithFrame:CGRectMake(0, 0, 40, 50)]; _activityIndicator.center = self.view.center; _activityIndicator.backgroundColor = [UIColor grayColor]; _activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyleWhiteLarge; [self.view addSubview:_activityIndicator]; }

3.滑动滑动条来改变网页字体大小

-(void)SliderChanged{ NSString *str1 = [NSString stringWithFormat:@"document.getElementsByTagName('body')[0].style.webkitTextSizeAdjust = '%f%%'",_slider.value]; [_webView stringByEvaluatingJavaScriptFromString:str1]; } @end

演示截图如下：