如何在xCode 4.2中从settings.bundle加载url

Question

我尝试用xCode编程，但这对我来说是新的。我想为ios5编写一个简单的webview应用程序。我的应用程序必须加载每次打开时在设置中定义的url。我创建xCode项目并添加设置。绑定到它：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>PreferenceSpecifiers</key>
    <array>
        <dict>
            <key>DefaultValue</key>
            <string>http://192.168.0.4/portal.aspx</string>
            <key>Key</key>
            <string>serverName</string>
            <key>KeyboardType</key>
            <string>Alphabet</string>
            <key>Title</key>
            <string>Server</string>
            <key>Type</key>
            <string>PSTextFieldSpecifier</string>
        </dict>
    </array>
    <key>StringsTable</key>
    <string>Root</string>
</dict>
</plist>

我的代码：

(void)viewDidLoad
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];   
    server = [defaults objectForKey:@"serverName"];    
    if(server==nil)
        server=@"http://google.com";    
    [super viewDidLoad];
    [proView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString: server]]];
    proView.scalesPageToFit= YES;
}

但我的应用程序总是启动谷歌页面。为什么服务器为零？服务器必须具有默认值？怎么了？

Answer 1

据我所知，您必须手动设置默认值，否则它们将为null。试试这个：

-(void)viewDidLoad {
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *server = [defaults objectForKey:@"serverName"];
NSLog(@"%@", server); // <-- should print null
//If the default value is null, set a value
if(server==nil) {
[defaults setObject:@"http://192.168.0.4/portal.aspx" forKey:@"serverName"];
//change your string to reflect the changes.
server = [defaults ObjectForKey:@"serverName"];
NSLog(@"%@", server); // <-- should print your URL
}
[defaults synchronize]; //Saves defaults.
[super viewDidLoad];
[proView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString: server]]];
proView.scalesPageToFit= YES;
}