ios中NSUserDefaults的施用

ios中NSUserDefaults的使用
创建一个user defaults方法有多个，最简单得快速创建方法:

图片一：保存数据之前；或者上一次没有保存数据，第二次启动的界面

图片二：保存了数据，第二次打开所看到的启动初始界面
- (void)defaultCheck:(id)sender{    NSLog(@" check按钮被按下   "); NSUserDefaults *accountDefaults = [NSUserDefaults standardUserDefaults]; if ([accountDefaults boolForKey:NCUserDefaultBoolForRegister] == NO) {  ((UIButton*)sender).selected = YES;  [accountDefaults setBool:YES forKey:NCUserDefaultBoolForRegister];  [accountDefaults setObject:nameField.text forKey:NCUserDefaultNameKey];  [accountDefaults setObject:pwdField.text forKey:NCUserDefaultPasswordKey]; } else {//YES  ((UIButton*)sender).selected = NO;  [accountDefaults setBool:NO forKey:NCUserDefaultBoolForRegister];  [accountDefaults setObject:nil forKey:NCUserDefaultNameKey];  [accountDefaults setObject:nil forKey:NCUserDefaultPasswordKey]; }}- (void)loadView {  [super loadView]; nameField = [[UITextField alloc]initWithFrame:CGRectMake(0, 0, 100, 30)]; pwdField = [[UITextField alloc]initWithFrame:CGRectMake(0, 0, 100, 30)]; [nameField setCenter:CGPointMake(160, 100)]; [pwdField setCenter:CGPointMake(160, 150)];  NSUserDefaults *accountDefaults = [NSUserDefaults standardUserDefaults];         //存的是bool值一定要用boolForKey:获取        //如果之前已经保存了User Defaults,那么在读取的时候就要将数据读取出来，显示在用户名和密码框中（这里没有加密）。 if ([accountDefaults boolForKey:NCUserDefaultBoolForRegister] == YES) {  nameField.text = [accountDefaults objectForKey:NCUserDefaultNameKey];  pwdField.text = [accountDefaults objectForKey:NCUserDefaultPasswordKey]; }else {    [nameField setPlaceholder:@"用户名"];        [pwdField setPlaceholder:@"密码"]; }  nameField.borderStyle = UITextBorderStyleBezel; [pwdField setBorderStyle:UITextBorderStyleRoundedRect]; [self.view addSubview:nameField]; [self.view addSubview:pwdField];  UIButton * loginBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect]; [loginBtn setFrame:CGRectMake(0, 0, 50, 30)]; [loginBtn setCenter:CGPointMake(200, 200)]; [loginBtn addTarget:self action:@selector(loginToWeiBo:) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:loginBtn];  UIButton * checkBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect]; [checkBtn setFrame:CGRectMake(0, 0, 20, 20)]; [checkBtn setCenter:CGPointMake(160, 180)];   //选中之后得图标 [checkBtn setBackgroundImage:[UIImage imageNamed:@"lock.png"] forState:(UIControlState)UIControlStateHighlighted]; [checkBtn setBackgroundImage:[UIImage imageNamed:@"lock.png"] forState:(UIControlState)UIControlStateSelected];      //未选中 [checkBtn setBackgroundImage:[UIImage imageNamed:@"unlock.png"] forState:(UIControlState)UIControlStateNormal]; [checkBtn addTarget:self action:@selector(defaultCheck:) forControlEvents:UIControlEventTouchUpInside];   //用户名和密码已经保存 if([accountDefaults boolForKey:NCUserDefaultBoolForRegister] == YES)  {  [checkBtn setSelected:YES]; }  [self.view addSubview:Btn];}
文章出处：http://xiaohui3837843.blog.163.com/blog/static/5438874020115823834836/