Question

我有一个基于视图的应用程序。现在在开场视图中，我有一些按钮，一张图片和一个小网页视图。

Web视图有自己的.h / .m文件，调用JSON请求来填充它。这很好用。

我的问题是，当应用关闭并重新打开时，webview不会更新。如何让它工作？

welcomeMessage.m（连接到webview）

- (void)awakeFromNib{ 

[NSThread sleepForTimeInterval:1];
NSUserDefaults *gMess =[NSUserDefaults standardUserDefaults];
NSString *myMess=[gMess stringForKey:@"welcomeMessage"];
NSLog(@"WEBVIEW CLASS %@",myMess);
if (myMess == NULL) {
    NSString *html = [NSString stringWithFormat:@"<body style ='background-color:#FFFF33' align='center'><p>Welcome</p><p>Check out our Daily Winners</p></body>"];
    [welcomeMessage loadHTMLString:html baseURL:[NSURL URLWithString:@"http://www.myapp.com/api/welcome/welcomemessage.php?iappid=37"]];
}
else{

    NSString *html = [NSString stringWithFormat:@"<body style ='background-color:#FFFF33' align='center'> %@ </body>", myMess];
    [welcomeMessage loadHTMLString:html baseURL:[NSURL URLWithString:@"http://www.myapp.com/api/welcome/welcomemessage.php?iappid=37"]];
}    
}

Mainviewcontroller json

- (void)viewDidLoad
{
// Create new SBJSON parser object

SBJsonParser *object = [[SBJsonParser alloc] init];

// Prepare URL request to download statuses from Twitter
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.kickintheapp.com/api/welcome/welcomemessage.php?iappid=37"]];
// NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://twitter.com/statuses/public_timeline.json"]];

// Perform request and get JSON back as a NSData object
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

// Get JSON as a NSString from NSData response
NSString *json_string = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];


NSError *jsonParseError;
NSDictionary *status = [object objectWithString:json_string error:&jsonParseError];
if (!status) {
    // there's been a parse error; look at jsonParseError
    // for example:
    NSLog(@"JSON parse error: %@", jsonParseError);
}
NSString *messValue = [status objectForKey:@"message"];
NSUserDefaults *gMess = [NSUserDefaults standardUserDefaults];
[gMess setObject:messValue forKey:@"welcomeMessage"];
}

Answer 1

查看Apple关于iOS生命周期的文档。你会在那里找到你需要的所有回调：

http://developer.apple.com/library/ios/#documentation/uikit/reference/UIApplicationDelegate_Protocol/Reference/Reference.html

特别是– applicationWillEnterForeground:会让你感兴趣。

自动从主视图重新加载UIwebview（基于视图的应用程序）

1 个答案: