UIWebView 未加载视图答案

【问题标题】：UIWebView Not Loading ViewUIWebView 未加载视图
【发布时间】：2014-03-25 21:52:29
【问题描述】：

我的 UIWebView 似乎没有加载：

- (void)viewDidAppear:(BOOL)animated {

[super viewDidAppear:animated];

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *urlAddress = [defaults stringForKey:@"webPage"];
NSLog(@"%@", urlAddress);

NSURLRequest *requestObj = [NSURLRequest requestWithURL:[NSURL URLWithString:urlAddress]];
webView.delegate = self;
[webView loadRequest:requestObj];

}

它在 UIViewController 中（通过 IB 连接）并且 urlAddress 返回 google.com

【问题讨论】：

标签： ios objective-c uiwebview

【解决方案1】：

你能检查获取的 URL 是否有效吗？

    NSString *urlAddress = [defaults stringForKey:@"webPage"];
    NSLog(@"%@", urlAddress);
    NSURL *u = [NSURL URLWithString:urlAddress];
    if(u){
      NSURLRequest *requestObj = [NSURLRequest requestWithURL:u];
      webView.delegate = self;
      [webView loadRequest:requestObj];
    }else{
      [[[UIAlertView alloc] initWithTitle:@"" message:@"invalid url." delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil] show];
    }

google.com 不是有效的 URL，它应该是 http://www.google.com。所以也许这就是这里的问题。

【讨论】：

对http:有效

【解决方案2】：

试试这个代码：

    - (void)viewDidAppear:(BOOL)animated 
    {
        [super viewDidAppear:animated];
        webView.delegate = self;
        NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
        NSString *urlAddress = [defaults stringForKey:@"webPage"];
        NSLog(@"%@", urlAddress);
        [self openURLFromString:urlAddress];
    }

    - (void) openURLFromString:(NSString*) urlString
    {
        NSURL *url = [self validateAddress:urlString];
        NSMutableURLRequest* request = [[NSMutableURLRequest alloc] initWithURL:url];
        [webView loadRequest:request];
    }

    - (NSURL*) validateAddress:(NSString*) address
    {
        NSURL* result = [NSURL URLWithString:address];
        if (!result.scheme)
        {
            NSString* modifiedURLString = [NSString stringWithFormat:@"http://%@", address];
            result = [NSURL URLWithString:modifiedURLString];
        }

        return result;
    }

    #pragma mark - UIWebViewDelegate
    - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSMutableURLRequest *)urlRequest navigationType:(UIWebViewNavigationType)navigationType
    {
        return YES;
    }

【讨论】：

【解决方案3】：

您缺少 URL (Click here to read more about this) 的 基本 URL 部分，这是必需的。

所以试试这个：

- (void)viewDidAppear:(BOOL)animated {

[super viewDidAppear:animated];

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *urlAddress = [defaults stringForKey:@"webPage"];
NSString * theURL = [NSString stringWithFormat:@"http://%@", urlAddress]; // you can also use stringByAppendingString if you prefer
NSLog(@"%@", theURL);

NSURLRequest *requestObj = [NSURLRequest requestWithURL:[NSURL URLWithString:theURL]];
webView.delegate = self;
[webView loadRequest:requestObj];

}

HTH :)

【讨论】：