IOS 实现UI状态保持和恢复

AppDelegate -(BOOL) application:(UIApplication *)application shouldSaveApplicationState:
(NSCoder *)coder
{
return YES;
}
-(BOOL) application:(UIApplication *)application shouldRestoreApplicationState:
(NSCoder *)coder
{
return YES;
}



在需要恢复的UIm文件中需要实现的函数：

-(void)encodeRestorableStateWithCoder:(NSCoder *)coder
{
[super encodeRestorableStateWithCoder:coder];
[coder encodeObject:self.txtField.text forKey:@"kSaveKey"];
}
-(void)decodeRestorableStateWithCoder:(NSCoder *)coder
{
[super decodeRestorableStateWithCoder:coder];
self.txtField.text = [coder decodeObjectForKey:@"kSaveKey"];
}