我正在使用ios中的 SWRevealViewController
进行导航抽屉。我有一个主屏幕,默认情况下,当应用启动时,我还显示了其他屏幕,例如设置,help,hiold。因此,当用户之间的用户在屏幕之间切换后,然后重置了第一视图控制器的状态。我想坚持其状态,如果在屏幕上显示一些数据,则不应将其删除。
我正在使用以下代码在屏幕之间切换。
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell=[self.tableView cellForRowAtIndexPath:indexPath];
if(indexPath.row==0)
{
[self performSegueWithIdentifier:@"home" sender:cell];
[cell setSelected:YES];
}
else if(indexPath.row==1)
{
[self performSegueWithIdentifier:@"settings" sender:cell];
}
else if(indexPath.row==2)
{
[self performSegueWithIdentifier:@"help" sender:cell];
}
else if(indexPath.row==3)
{
[self performSegueWithIdentifier:@“about” sender:cell];
}
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
NSLog(@"Segue");
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
UINavigationController *destViewController = (UINavigationController*)segue.destinationViewController;
destViewController.title = [[titles objectAtIndex:indexPath.row] capitalizedString];
if([segue.identifier isEqualToString:@"settings"])
{
self.revealViewController.navigationItem.title = @"Settings";
}
else if([segue.identifier isEqualToString:@"help"])
{
self.revealViewController.navigationItem.title = @"help";
}
else if([segue.identifier isEqualToString:@"about"])
{
self.revealViewController.navigationItem.title = @"about";
}
if([segue isKindOfClass:[SWRevealViewControllerSegue class]])
{
SWRevealViewControllerSegue *swSegue = (SWRevealViewControllerSegue*) segue;
swSegue.performBlock = ^(SWRevealViewControllerSegue* rvc_segue, UIViewController* svc, UIViewController* dvc) {
UINavigationController* navController = (UINavigationController*)self.revealViewController.frontViewController;
[navController setViewControllers: @[dvc] animated: NO ];
[self.revealViewController setFrontViewPosition: FrontViewPositionLeft animated: YES];
};
}
}
一个解决方案我看到,要将ViewController保存在导航堆栈中,以便当用户转到"家居"时,ViewController不会被破坏,然后将其从导航堆栈中重新启动,而不是再次初始化视图控制器。
例如,对于helpvc,您将其属性存储在您的身边Mennu View Controller中:
@property (nonatomic, strong) HelpViewContoller* helpVC;
而不是在行选择中而不是调用您的segue,而是实例化视图控制器,但是在检查它是否已经实例化之前,您已经使用了:
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell=[self.tableView cellForRowAtIndexPath:indexPath];
if(indexPath.row==0) {
if (helpVC == nil) {
helpVC = [self.storyboard instantiateViewControllerWithIdentifier:@"helpVCidentifier"];
[self changeFrontVCto:helpVC];
}
}
}
-(void) changeFrontVCto:(UIViewController*)vc {
UINavigationController* navController = (UINavigationController*)self.revealViewController.frontViewController;
[navController setViewControllers: @[vc] animated: NO ];
[self.revealViewController setFrontViewPosition: FrontViewPositionLeft animated: YES];
}