[IOS]UIWebView实现保存页面和读取服务器端json数据

如何通过viewView保存访问过的页面？和如何获取并解析服务器端发送过来的json数据？通过一个简单的Demo来学习一下吧！

操作步骤：

1.创建SingleViewApplication应用，新建VIewController，并在xib试图中添加WebView，继承webview的Delegate协议。

2.将ViewController类遵循UIWebViewDelegate和NSURLConnectionDataDelegate协议，并且实现协议中的方法。

ViewController.h：

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UIWebViewDelegate,NSURLConnectionDataDelegate>
@property (retain, nonatomic) IBOutlet UIWebView *webview;
@property (retain, nonatomic) UIAlertView * alert;
@property (retain, nonatomic) IBOutlet UITextField *searchText;
- (IBAction)searchClick:(id)sender;


@property (retain, nonatomic) IBOutlet UILabel *label;
@property (retain, nonatomic) NSURLConnection * connection;
@property (retain, nonatomic) NSMutableData * data;
@end

VIewController.m:

#import "ViewController.h"

@interfaceViewController ()

@end

@implementation ViewController

- (void)viewDidLoad

{

    [superviewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

    

    //请求网络页面

//    NSURL * url = [NSURL URLWithString:@"http://www.taobao.com"];   //一定要加http://

//    NSURLRequest * request = [NSURLRequest requestWithURL:url];

//    [self.webview loadRequest:request];

//    

//    

//    //html加载本地网页

//    NSString * str = [[NSBundle mainBundle] pathForResource:@"百度图片—全球最大中文图片库" ofType:@"html"];

//    str = [NSString stringWithContentsOfFile:str encoding:NSUTF8StringEncoding error:nil];

//    NSLog(@"%@",str);

//    [self.webview loadHTMLString:str baseURL:[[NSBundle mainBundle]bundleURL]];

//    

    

    

    self.label.text = @"正在请求数据";

    //step1:请求地址

    //保存页面

    //NSString * urlString = @"http://www.baidu.com";

    //访问服务器获取json数据

    NSString * urlString = @"http://www.weather.com.cn/data/cityinfo/101020100.html";

    NSURL * url = [NSURL URLWithString:urlString];

    //step2:实例化一个request

    NSURLRequest * request = [NSURLRequestrequestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicytimeoutInterval:30.0];

    //step3:创建链接

    self.connection = [[NSURLConnectionalloc] initWithRequest:request delegate:self];

    if(self.connection)

    {

        NSLog(@"创建链接成功");

    }else{

        NSLog(@"创建链接失败");

    }

    [url release];

    [urlString release];

    

}

- (void)didReceiveMemoryWarning

{

    [superdidReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

- (void)dealloc {

    [_webview release];

    [_searchTextrelease];

    [_label release];

    [super dealloc];

}

//获取数据

-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response

{

    //接受一个服务端回话，再次一般初始化接受数据的对象

    //NSLog(@"返回数据类型%@",[response ]);

    //NSLog(@"返回数据编码%@",[response text]);

    NSMutableData * data = [[NSMutableDataalloc] init];

    self.data = data;

    [data release];

}

//不断的获取数据

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data

{

    //接受返回数据，这个方法可能会被调用多次，因此将多次返回数据加起来

    NSInteger datalength = [data length];

    NSLog(@"返回数据量：%d",datalength);

    [self.data appendData:data];

}

//获取文件地址

-(NSString *)dataFilePath:(NSString*)fileName

{

    NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    NSString *document=[paths objectAtIndex:0];

    return [document stringByAppendingPathComponent:fileName];

}

-(void)connectionDidFinishLoading:(NSURLConnection *)connection

{

//    //连接结束

    NSLog(@"%d",[self.data length]);

    self.label.text = @"请求结束";

    //可以下载图片

    //[self.data writeToFile:[self dataFilePath:@"image.jpg"] atomically:YES];

    

    NSString * mystr = [[NSStringalloc] initWithData:self.dataencoding:NSUTF8StringEncoding];

    [mystr writeToFile:[self dataFilePath:@"百度图片—全球最大中文图片库.html"] atomically:YES encoding:NSUTF8StringEncoding error:nil];

    NSLog(@"最后的结果%@",mystr);

    [mystr release];

    

//    NSDictionary *weather = [NSJSONSerialization JSONObjectWithData:self.data options:NSJSONReadingMutableContainers  error:nil];

//    NSLog(@"%@",weather);

//    [weather writeToFile:[self dataFilePath:@"weather.plist"] atomically:YES];

}

-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error

{

    self.label.text = @"连接失败";

}

- (IBAction)searchClick:(id)sender {

}

@end

结果：

2013-08-27 16:09:18.821 WebViewDemo[673:c07] 创建链接成功

2013-08-27 16:09:19.161 WebViewDemo[673:c07] 返回数据量：153

2013-08-27 16:09:19.161 WebViewDemo[673:c07] 153

2013-08-27 16:09:19.193 WebViewDemo[673:c07] 最后的结果{"weatherinfo":{"city":"上海","cityid":"101020100","temp1":"32℃","temp2":"27℃","weather":"多云","img1":"d1.gif","img2":"n1.gif","ptime":"11:00"}}