ios开发入门篇（四）：UIWebView结合UISearchBar的简单用法

2019-11-14 19:51:33

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　　 UIWebView是ios开发中比较常用的一个控件。我们可以用它来浏览网页、打开文档等，今天笔者在这里简单介绍下UIWebView和UISearchBar结合起来的用法，做一个简单的类浏览器。

　　一：首先定义这两个控件，并在.h文件中实现UISearchBarDelegate,UIWebViewDelegate两个代理

　　@interface TestView : UIViewController<UISearchBarDelegate,UIWebViewDelegate>

　　@PRoperty(nonatomic)UISearchBar* searchBar;

　@property(nonatomic,retain)UIWebView* webView;

　　二：加载这两个控件

//加载searcBar-(void)initSearchBar{    self.searchBar = [[UISearchBar alloc]initWithFrame:CGRectMake(0, 20, [UIScreen mainScreen].bounds.size.width, 40)];    self.searchBar.delegate = self;             //接受委托    self.searchBar.text = @"http://";    //UISearchBar上按钮的默认文字为Cancel，这里改为“GO”版本不同方法有些许区别    for(id cc in [self.searchBar subviews])    {        for (UIView *view in [cc subviews]) {            if ([NSStringFromClass(view.class) isEqualToString:@"UINavigationButton"])            {                UIButton *btn = (UIButton *)view;                [btn setTitle:@"GO" forState:UIControlStateNormal];            }        }    }        [self.view addSubview:self.searchBar];    }//加载webview-(void)initWebView{    self.webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 60, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height-60)];    [self.webView setUserInteractionEnabled:YES];             //设置是否支持交互    [self.webView setDelegate:self];                          //接受委托    [self.webView setScalesPageToFit:YES];                    //设置自动缩放    [self.view addSubview:self.webView];}

在viewDidLoad执行加载

-(void)viewDidLoad{    [super viewDidLoad];    [self.view setBackgroundColor:[UIColor whiteColor]];    [self initSearchBar];    [self initWebView];    }

　　三：实现seachBar的代理方法

#pragma UISearchBar//点击searchbar上的GO  时调用- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar{    [self doSearch:searchBar];}//点击键盘上的search时调用- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar{    [searchBar resignFirstResponder];    [self doSearch:searchBar];}//开始执行搜索  - (void)doSearch:(UISearchBar *)searchBar{    [searchBar resignFirstResponder];    NSURL* url = [NSURL URLWithString:[NSString stringWithFormat:@"%@",searchBar.text]];    NSURLRequest *request =[NSURLRequest requestWithURL:url];    [self.webView loadRequest:request];}

在这里

　　NSURL* url = [NSURL URLWithString:[NSString stringWithFormat:@"%@",searchBar.text]];    NSURLRequest *request =[NSURLRequest requestWithURL:url];    [self.webView loadRequest:request];

这段代码就是为webView加载网页的方式，其他方式的还有

 //加载本地文件资源//    NSURL *url = [NSURL fileURLWithPath:@"文件路径"]; //    NSURLRequest *request = [NSURLRequest requestWithURL:url];//    [webView loadRequest:request]；//读入一个HTML代码//    NSString *htmlPath = [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent:@"HTML文件地址"];//    NSString *htmlString = [NSString stringWithContentsOfFile: htmlPath encoding:NSUTF8StringEncoding error:NULL];//    [webView loaDHTMLString:htmlString baseURL:[NSURL fileURLWithPath:htmlPath]];

四：实现webView加载失败时的代理方法

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error{    UIAlertView *alterview = [[UIAlertView alloc] initWithTitle:@"访问出错" message:[error localizedDescription]  delegate:nil cancelButtonTitle:nil otherButtonTitles:@"OK", nil];    [alterview show];}

另外，UIWebView常用的代理方法还有

- (void )webViewDidStartLoad:(UIWebView  *)webView   //网页开始加载的时候调用- (void )webViewDidFinishLoad:(UIWebView  *)webView  //网页加载完成的时候调用-(BOOL )webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType )navigationType//当UIWebView加载网页的时候就会调用到此函数，然后执行webViewDidStartLoad函数，可以在函数中进行请求解析，地址分析等

代码敲完后，来看一下运行的结果