ios--OC调用JS并获得返回值(实例)

原地址：http://www.2cto.com/kf/201402/281514.html

1、准备一个本地化的html网页，如jsIOS.html

  <meta http-equiv= "content-type" content= "text/html;charset=utf-8" >
  <title>js调用oc</title>
  <script type= "text/javaScript" >
      function postStr(){
           return document.getElementById( "text1" ).value;
           //return "javaScript返回值啦";
      }
  </script>


<p><input type= "text" id= "text1" value= "返回值" ></p>

2、将此html文件放到项目代码目录里面，如图：

3、拖一个UIWebView控件和UIButton控件到xxxViewController对应的.xib或.storyboard视图的UIView上；

在xxxViewController的.h文件中分别声明UIWebView类型变量和UIButton类型的变量，以及一个按钮点击事件(并且跟视图里面的控件连线)，

并且添加一个UIWebViewDelegate类型的委托。<喎�"http://www.2cto.com/kf/ware/vc/" target="_blank" class="keylink">vcD4KPHA+eHh4Vmlld0NvbnRyb2xsZXIuaM7EvP7E2sjdyOfPwqO6PC9wPgo8cD48L3A+CjxwIGNsYXNzPQ=="p1">

# import <uikit uikit.h= "" >

@interface ViewController : UIViewController <uiwebviewdelegate>
@property (nonatomic,retain) IBOutlet UIWebView *webview;
@property (nonatomic,retain) IBOutlet UIButton *button;
-(IBAction)IOS_JS:(id)sender;
@end </uiwebviewdelegate></uikit>

4、在xxxViewController.m文件中实现通过点击事件，调用javaScript的方法并取得返回值。

代码如下：

# import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController
@synthesize webview;

- ( void )viewDidLoad
{
    [ super viewDidLoad];
    //设置webView
    webview.backgroundColor = [UIColor clearColor];
    //webview.scalesPageToFit =YES;
    webview.delegate =self;
    //找到jsIOS.html文件的路径
    NSString *basePath = [[NSBundle mainBundle]bundlePath];
    NSString *helpHtmlPath = [basePath stringByAppendingPathComponent:@ "jsIOS.html" ];
    NSURL *url = [NSURL fileURLWithPath:helpHtmlPath];
    //加载本地html文件
    [webview loadRequest:[NSURLRequest requestWithURL:url]];
}

/*
 * 点击事件
 * 调用javaScript的方法postStr()并取得返回值
 * 输出返回值到控制台
 */
-(IBAction)IOS_JS:(id)sender
{
    NSString *str = [self.webview stringByEvaluatingJavaScriptFromString:@ "postStr();" ];
    NSLog(@ "JS返回值：%@" ,str);
}


- ( void )didReceiveMemoryWarning
{
    [ super didReceiveMemoryWarning];
}
@end