#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>

#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