IOS provides many ways of storing data of an application. One of
this way is called NSUserDefaults. NSUserDefaults allow you to save and
retrieve data in the form of key, value pair.
NSUserDefaults class provides its own built in mechanisms
to save float, double, integers, Boolean and URL data. To save a custom object
it should be converted to NSData object using NSUserDefaults.
Storing
NSUserDefaults.StandardUserDefaults.SetString("value",
"key");
Example1:
NSUserDefaults values = new NSUserDefaults();
// Store value on Userdefaults
values .SetString(txtString.Text, "stringvalue");
values .SetInt(Int32.Parse(txtInteger.Text), "integervalue");
// Get values form Userdefaults
lblString.Text = values .StringForKey("stringvalue");
lblInteger.Text = values .IntForKey("integervalue").ToString();
lblBoolean.Text = values .BoolForKey("swithvalue").ToString();
NSUserDefaults.StandardUserDefaults.Synchronize();
Retrieve
NSUserDefaults.StandardUserDefaults.StringForKey("key");
Clear:
NSUserDefaults.StandardUserDefaults.RemoveObject("key");
Example 2:
public partial class ViewController : UIViewController
{
public static string UserNameKey = "user_name";
protected ViewController(IntPtr handle) : base(handle)
{
// Note: this .ctor should not contain any initialization logic.
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
SaveUserName(UserNameKey, "Subramanyam");
var readUserName = ReadUserName();
}
public override void DidReceiveMemoryWarning()
{
base.DidReceiveMemoryWarning();
// Release any cached data, images, etc that aren't in use.
}
void SaveUserName(string key, string value){
var plist = NSUserDefaults.StandardUserDefaults;
plist.SetString(value, key);
plist.Synchronize();
}
string ReadUserName( )
{
return NSUserDefaults.StandardUserDefaults.StringForKey(UserNameKey);
}
}
