iOS - 为啥我的下一个视图回调我以前的视图？
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【中文标题】iOS - 为啥我的下一个视图回调我以前的视图？【英文标题】：iOS - Why my next view callback my previous view?iOS - 为什么我的下一个视图回调我以前的视图？ 【发布时间】：2018-05-28 10:55:52 【问题描述】：我的情况是下一个：
我有两个视图控制器。
第一个包含UITableView。当我点击一个单元格时，会调用第二个视图并显示另一个 UITableView。
问题： 我的第二个视图立即显示出来，它被删除了，我的应用又回到了第一个视图。
在调试模式下，我可以看到viewDidLoad() 被调用并且TableView 已被初始化，因为TableView 已被填充。
但是不知道为什么，立即调用viewWillDisappear()，好像视图被移除了一样……
有人可以帮帮我吗？
编辑：
我的第一个视图：
#import "CIMSaddlesResearchesSavedViewController.h"
#import <Foundation/Foundation.h>
@interface CIMSaddlesResearchesSavedViewController ()
@property (weak, nonatomic) IBOutlet UITableView *tableView;
@end
@implementation CIMSaddlesResearchesSavedViewController
- (void)viewDidLoad
[super viewDidLoad];
self.tableView.tableFooterView = [[UIView alloc] initWithFrame:CGRectZero];
- (void) viewWillAppear:(BOOL)animated
[super viewWillAppear:animated];
[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"NavigationBarBackground"] forBarMetrics:UIBarMetricsDefault];
- (void) viewWillDisappear:(BOOL)animated
[super viewWillDisappear:animated];
[self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
- (UIStatusBarStyle) preferredStatusBarStyle
return UIStatusBarStyleLightContent;
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
return 1;
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
return [self.researches count];
- (UITableViewCell *)tableView:(nonnull UITableView *)tableView cellForRowAtIndexPath:(nonnull NSIndexPath *)indexPath
static NSString *reuseIdentifier = @"researchCell";
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:reuseIdentifier];
CIMSaddleResearch *research;
research = self.researches[indexPath.row];
if (cell == nil)
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:@"researchCell"];
cell.textLabel.textColor = [UIColor whiteColor];
cell.detailTextLabel.textColor = [UIColor whiteColor];
cell.backgroundColor = [UIColor clearColor];
if (research.dbId && ![research.dbId isEqual:@""])
CIMDbManager *dbMngr = [[CIMDbManager alloc] init];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"dd/MM/yyyy"];
NSMutableString *minPrice = [NSMutableString stringWithString:@""];
NSMutableString *maxPrice = [NSMutableString stringWithString:@""];
NSMutableString *currencyS = [NSMutableString stringWithString:@""];
CIMCurrency *currency = [[CIMCurrency alloc] init];;
NSMutableString *researchText = [NSMutableString stringWithString:@""];
if (research.customer && ![research.customer isEqual:@""])
CIMCustomer *customer = [[CIMCustomer alloc] init];
customer.dbId = research.customer;
customer = [dbMngr firstObjectFromDb:customer];
[researchText appendFormat:@"%@ le %@", customer.lastName, [formatter stringFromDate:research.date]];
CIMSaddleResearchLine *researchLine = [[CIMSaddleResearchLine alloc] init];
researchLine.saddleResearch = research.dbId;
NSArray *lines = [dbMngr objectsFromDb:researchLine];
for(CIMSaddleResearchLine *line in lines)
if([line.field isEqualToString:@"PRIX_MIN"])
[minPrice appendFormat:@"%@", line.value];
else if([line.field isEqualToString:@"PRIX_MAX"])
[maxPrice appendFormat:@"%@", line.value];
else if([line.field isEqualToString:@"DEVISE"])
[currencyS appendFormat:@"%@", line.value];
if(![minPrice isEqual:@""] || ![maxPrice isEqual:@""])
if(currencyS)
currency.dbId = currencyS;
currency = [dbMngr firstObjectFromDb:currency];
else
currency = [dbMngr defaultSocietyCurrency];
[researchText appendString:@" | Budget : "];
if(![minPrice isEqual:@""] && ![maxPrice isEqual:@""])
[researchText appendFormat:@"%@%@ → %@%@", minPrice, currency.symbol, maxPrice, currency.symbol];
else if(![minPrice isEqual:@""] && [maxPrice isEqual:@""])
[researchText appendFormat:@"%@%@ min.", minPrice, currency.symbol];
else if([minPrice isEqual:@""] && ![maxPrice isEqual:@""])
[researchText appendFormat:@"%@%@ max.", maxPrice, currency.symbol];
NSMutableString *researchDetailText = [NSMutableString stringWithFormat:@"Relance le : %@", [formatter stringFromDate:research.deadline]];
CIMResearchStatus *status = [[CIMResearchStatus alloc] init];
status.dbId = research.status;
status = [dbMngr firstObjectFromDb:status];
if(status)
[researchDetailText appendFormat:@" (%@)", status.name];
cell.textLabel.text = researchText;
cell.detailTextLabel.text = researchDetailText;
if (research.comment && ![research.comment isEqual:@""] )
cell.accessoryType = UITableViewCellAccessoryDetailDisclosureButton;
else
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"saddleCell"];
cell.backgroundColor = [UIColor clearColor];
cell.textLabel.text = NSLocalizedString(@"The saddle is not in this list", nil);
cell.textLabel.textAlignment = NSTextAlignmentCenter;
return cell;
-(void) tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath
CIMSaddleResearch *research = self.researches[indexPath.row];
if (research.comment && ![research.comment isEqual:@""] )
UIAlertController *alert = [UIAlertController alertControllerWithTitle:NSLocalizedString(@"Comment", nil)
message:research.comment
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *actionOk = [UIAlertAction actionWithTitle:NSLocalizedString(@"Ok", nil)
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action)];
[alert addAction:actionOk];
[self presentViewController:alert animated:YES completion:nil];
[tableView deselectRowAtIndexPath:indexPath animated:YES];
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
[self.navigationController popViewControllerAnimated:YES];
[tableView deselectRowAtIndexPath:indexPath animated:YES];
#pragma mark - Navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
if ([segue.identifier isEqualToString:@"openResultResearch"])
UITableView *table = (UITableView*)[(UITableViewCell*)sender superview];
NSIndexPath *index = [table indexPathForCell:(UITableViewCell*) sender];
CIMSaddleResearch *research = self.researches[index.row];
CIMDbManager *dbMngr = [[CIMDbManager alloc] init];
CIMSaddleResearchLine *researchLine = [[CIMSaddleResearchLine alloc] init];
CIMSaddleResearchFormViewController *form = [[CIMSaddleResearchFormViewController alloc] init];
form.minimumPriceRow = [[XLFormRowDescriptor alloc] init];
form.maximumPriceRow = [[XLFormRowDescriptor alloc] init];
form.minimumYearRow = [[XLFormRowDescriptor alloc] init];
form.maximumYearRow = [[XLFormRowDescriptor alloc] init];
form.currency = [[CIMCurrency alloc] init];
NSMutableDictionary *filters = [[NSMutableDictionary alloc] initWithObjectsAndKeys:
[[NSMutableArray alloc] init], @"brand",
[[NSMutableArray alloc] init], @"model",
[[NSMutableArray alloc] init], @"size",
[[NSMutableArray alloc] init], @"color",
[[NSMutableArray alloc] init], @"finishing",
nil];
researchLine.saddleResearch = research.dbId;
NSArray *lines = [dbMngr objectsFromDb:researchLine];
NSSortDescriptor *sortFieldDesc = [[NSSortDescriptor alloc] initWithKey:@"field" ascending:YES selector:@selector(compare:)];
NSSortDescriptor *sortOrderDesc = [[NSSortDescriptor alloc] initWithKey:@"order" ascending:YES selector:@selector(compare:)];
lines = [lines sortedArrayUsingDescriptors:@[sortFieldDesc, sortOrderDesc]];
for(CIMSaddleResearchLine *line in lines)
if([line.field isEqualToString:@"PRIX_MIN"])
form.minimumPriceRow.value = line.value;
else if([line.field isEqualToString:@"PRIX_MAX"])
form.maximumPriceRow.value = line.value;
else if([line.field isEqualToString:@"ANNEE_MIN"])
form.minimumYearRow.value = line.value;
else if([line.field isEqualToString:@"ANNEE_MAX"])
form.maximumYearRow.value = line.value;
else if([line.field isEqualToString:@"DEVISE"])
form.currency.dbId = line.value;
form.currency = [dbMngr firstObjectFromDb:form.currency];
else if([line.field isEqualToString:@"GA_REFCONSTRUC"])
form.serialNumberRow.value = line.value;
else if([line.field isEqualToString:@"GA_QUARTIER"])
form.flapRow.value = line.value;
else if([line.field isEqualToString:@"GA_MARQUE"])
CIMBrand *brand = [[CIMBrand alloc] init];
brand.dbId = line.value;
[[filters objectForKey:@"brand"] addObject:[dbMngr firstObjectFromDb:brand]];
else if([line.field isEqualToString:@"GA_MODEL"])
CIMModel *model = [[CIMModel alloc] init];
model.dbId = line.value;
[[filters objectForKey:@"model"] addObject:[dbMngr firstObjectFromDb:model]];
else if([line.field isEqualToString:@"GA_TAILLE"])
CIMSize *size = [[CIMSize alloc] init];
size.dbId = line.value;
[[filters objectForKey:@"size"] addObject:[dbMngr firstObjectFromDb:size]];
else if([line.field isEqualToString:@"GA_COULEUR"])
CIMColor *color = [[CIMColor alloc] init];
color.dbId = line.value;
[[filters objectForKey:@"color"] addObject:[dbMngr firstObjectFromDb:color]];
else if([line.field isEqualToString:@"GA_FINITION"])
CIMFinishing *finishing = [[CIMFinishing alloc] init];
finishing.dbId = line.value;
[[filters objectForKey:@"finishing"] addObject:[dbMngr firstObjectFromDb:finishing]];
if(!form.currency.dbId && [form.currency.dbId isEqualToString:@""])
CIMCustomer *customer = [[CIMCustomer alloc] init];
customer.dbId = research.customer;
customer = [dbMngr firstObjectFromDb:customer];
form.currency.dbId = customer.currency;
form.currency = [dbMngr firstObjectFromDb:form.currency];
CIMSaddlesViewController *saddlesViewController = segue.destinationViewController;
saddlesViewController.filters = filters;
saddlesViewController.saddleDbId = [NSMutableString stringWithString:@""];
saddlesViewController.selectionMode = NO;
saddlesViewController.saddleNotFoundOption = NO;
saddlesViewController.showSaddlePictures = YES;
saddlesViewController.showSaddleWarehouse = YES;
saddlesViewController.showToolbar = NO;
saddlesViewController.saddles = [dbMngr stockSaddlesWithFilters:filters
andSerialNumber:form.serialNumberRow.value
andFlap:form.flapRow.value
betweenMinimumPrice:form.minimumPriceRow.value
andMaximumPrice:form.maximumPriceRow.value
inCurrency:form.currency.dbId
betweenMinimumYear:form.minimumYearRow.value
andMaximumYear:form.maximumYearRow.value
inStock:YES];
saddlesViewController.formResearch = form;
saddlesViewController.saddlesPricesCurrency = form.currency;
@end
我的第二个观点：
#import "CIMSaddlesViewController.h"
@interface CIMSaddlesViewController ()
@property (weak, nonatomic) IBOutlet UITableView *tableView;
@end
@implementation CIMSaddlesViewController
- (void)viewDidLoad
[super viewDidLoad];
self.tableView.tableFooterView = [[UIView alloc] initWithFrame:CGRectZero];
- (void) viewWillAppear:(BOOL)animated
[super viewWillAppear:animated];
[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"NavigationBarBackground"] forBarMetrics:UIBarMetricsDefault];
- (void) viewWillDisappear:(BOOL)animated
[super viewWillDisappear:animated];
[self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
- (UIStatusBarStyle) preferredStatusBarStyle
return UIStatusBarStyleLightContent;
- (void)didReceiveMemoryWarning
[super didReceiveMemoryWarning];
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
return 1;
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
return [self.saddles count];
- (UITableViewCell *)tableView:(nonnull UITableView *)tableView cellForRowAtIndexPath:(nonnull NSIndexPath *)indexPath
static NSString *reuseIdentifier = @"saddleCell";
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:reuseIdentifier];
CIMItem *saddle;
saddle = self.saddles[indexPath.row];
if (cell == nil)
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:@"saddleCell"];
cell.textLabel.textColor = [UIColor whiteColor];
cell.detailTextLabel.textColor = [UIColor whiteColor];
cell.backgroundColor = [UIColor clearColor];
if (saddle.dbId && ![saddle.dbId isEqual:@""])
NSMutableString *saddleText = [NSMutableString stringWithString:saddle.dbId];
NSMutableString *saddleDetailText = [NSMutableString stringWithString:saddle.name];
// Serial number
if (saddle.serialNumber && ![saddle.serialNumber isEqual:@""])
[saddleText appendFormat:@" - %@", saddle.serialNumber];
// Warehouse
if (self.showSaddleWarehouse)
CIMDbManager *dbMngr = [[CIMDbManager alloc] init];
CIMStock *stock = [[CIMStock alloc] init];
stock.item = saddle.dbId;
stock.quantity = [NSNumber numberWithInt:1];
stock = [dbMngr firstObjectFromDb:stock];
if (stock)
CIMWarehouse *warehouse = [[CIMWarehouse alloc] init];
warehouse.dbId = stock.warehouse;
warehouse = [dbMngr firstObjectFromDb:warehouse];
[saddleText appendFormat:@" → [%@]", warehouse.name];
// Estimed price
if (self.saddlesPricesCurrency)
CIMDbManager *dbMngr = [[CIMDbManager alloc] init];
CIMSaddlePrices *saddlePrices = [[CIMSaddlePrices alloc] init];
saddlePrices.item = saddle.dbId;
saddlePrices.currency = self.saddlesPricesCurrency.dbId;
saddlePrices = [dbMngr firstObjectFromDb:saddlePrices];
if (saddlePrices)
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setMaximumFractionDigits:0];
[numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
[numberFormatter setCurrencyCode:self.saddlesPricesCurrency.isoCode];
NSString *isEstimateStr;
if ([saddlePrices.isEstimate isEqual:@"-"])
isEstimateStr = NSLocalizedString(@"Official price", nil);
else
isEstimateStr = NSLocalizedString(@"Estimation", nil);
[saddleText appendFormat:@" | %@ (%@)", [numberFormatter stringFromNumber:saddlePrices.price], isEstimateStr];
cell.textLabel.text = saddleText;
cell.detailTextLabel.text = saddleDetailText;
// Saddle pictures
if (self.showSaddlePictures && [[self.saddlesPicturesDictionary allKeys] containsObject:saddle.dbId])
UIButton *accessoryButton = [[UIButton alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 40.0f, 40.0f)];
if ([self.saddlesiPadPictures containsObject:saddle.dbId])
[accessoryButton setImage:[UIImage imageNamed:@"SaddleiPadPictureButton"] forState:UIControlStateNormal];
else
[accessoryButton setImage:[UIImage imageNamed:@"SaddlePictureButton"] forState:UIControlStateNormal];
accessoryButton.tag = indexPath.row;
[accessoryButton addTarget:self action:@selector(showSaddlePicturesViewForSaddleWithSender:) forControlEvents:UIControlEventTouchDown];
cell.accessoryView = accessoryButton;
else
cell.accessoryView = nil;
else
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"saddleCell"];
cell.backgroundColor = [UIColor whiteColor];
cell.textLabel.text = NSLocalizedString(@"The saddle is not in this list", nil);
cell.textLabel.textAlignment = NSTextAlignmentCenter;
return cell;
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
if (self.selectionMode)
CIMItem *saddle = self.saddles[indexPath.row];
[self.saddleDbId setString:saddle.dbId];
[self.navigationController popViewControllerAnimated:YES];
else
[self.tableView deselectRowAtIndexPath:indexPath animated:YES];
@end
说实话，这个项目很大，我从两个月前就开始做，我一个人在做。我之前没有在 Objective-C 中工作，甚至更少使用 X-Code。我正在逐渐发现功能和 Objective-C...
【问题讨论】：
显示您的第二次查看代码 是的，请添加您的第二个视图控制器的完整代码 【参考方案1】：在您的第一个 VC 中，您调用 [self.navigationController popViewControllerAnimated:YES];，它告诉 navigationVC 弹出当前可见的视图控制器。如果您在第一个 VC 中为 tableview didSelectRowAtIndexPath: 设置断点，在第二个 VC 中为 viewDidLoad 设置断点，您将看到它们被调用的顺序。我感觉执行顺序可能如下：
-
为 firstVC 中的 segue 做准备
在 secondVC 中确实加载了视图
didSelectRowAtIndexPath 在第一个 VC 中
你的第二个 VC 终于卸载了
这是我的想法，未经测试。请确保您确实需要在 didSelectRow 中弹出 VC
【讨论】：
你的想法是错误的，但它帮助我找到了真正的解决方案，它接近你的想法：我评论了 [self.navigationController popViewControllerAnimated:YES];在我的第一个 VC 中，它可以工作......但我不确定为什么 如果你从单元格到 secondVC 设置一个 segue，则 segue 在 didselectrow 之前被调用，并且当 popViewcontroller 被调用时，你在导航 VC 中有第二个 VC（因此它在 viewDidLoad 之后立即返回）。试试这个：删除你的 segue，创建一个新的 viewController segue（从一个 viewController 拖到另一个并给它一个标识符）。这会改变执行顺序，并且 didselectRow 将在 prepareForSegue 之前被调用。不要忘记在 didSelectRowatIndexPath 方法中调用[self performSegueWithIdentifier:@"Segue" sender:self]。以上是关于iOS - 为啥我的下一个视图回调我以前的视图？的主要内容，如果未能解决你的问题，请参考以下文章