我在 viewController 中有以下代码。我在视图上有一个 NavigationController（这是子视图 - 父视图的代码工作正常）
当我在父级上选择一个选项时会发生什么，这个 viewController 会加载。用户可以从子 viewController 中选择一个选项来打开带有 DocumentInteractionController 的 PDF 文件（效果很好）。
问题是当我尝试返回父视图控制器时，消息被发送到子视图控制器，就好像它仍然被分配一样。我在设置它时看到了类似的东西，因为对子 viewController 中的方法有多次调用。
对我做错了什么有任何想法吗？
#import "DetailViewController.h"
@interface DetailViewController ()
@end
@implementation DetailViewController
@synthesize node;
@synthesize replies;
@synthesize docController;
- (void) viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self.tableView reloadData];
[self.tableView setContentOffset:CGPointZero animated:NO];
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
[self.docController init];
// Do any additional setup after loading the view from its nib.
}
- (void) dealloc
{
[self.docController release];
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (NSInteger) numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger) tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if (self.replies == nil)
{
self.replies = [[NSArray alloc] init];
self.actions = [[NSArray alloc] init];
}
if(self.replies.count == 0)
{
self.replies = [self.node nodesForXPath:@"./question/reply/text" error:nil];
self.actions = [self.node nodesForXPath:@"./question/reply/response/action" error:nil];
}
return self.replies.count;
}
- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"QuestionCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
// Get the object to display and set the value in the cell
NSString *cellText = [[replies objectAtIndex:indexPath.row] stringValue];
cell.textLabel.text = cellText;
return cell;
}
- (void) showOptionsMenu:(NSString *) fileName
{
NSString *fileToOpen = [[NSBundle mainBundle] pathForResource:fileName ofType:@"pdf"];
NSURL *fileURL = [NSURL fileURLWithPath:fileToOpen];
self.docController = [self setupControllerWithURL:fileURL usingDelegate:self];
bool didShow = [self.docController presentOptionsMenuFromRect:CGRectMake(0, 0, 150, 150) inView: self.view animated:YES];
if(!didShow)
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"" message:@"Sorry, app not found" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
}
}
- (void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *action = [[self.actions objectAtIndex:indexPath.row] stringValue];
[self showOptionsMenu:action];
}
- (UIDocumentInteractionController *) setupControllerWithURL: (NSURL *) fileURL usingDelegate:(id <UIDocumentInteractionControllerDelegate>) interactionDelegate
{
UIDocumentInteractionController *interactionController = [UIDocumentInteractionController interactionControllerWithURL:fileURL];
interactionController.delegate = interactionDelegate;
return interactionController;
}
@end
编辑
添加父视图控制器的代码......也许我在那里做错了什么？我正在使用 GDataXML 根据 XML 文件的内容加载问答应用程序...
@implementation ViewController
@synthesize currentReply;
@synthesize questions;
- (void)viewDidLoad
{
[super viewDidLoad];
[self setUpQuestions];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)dealloc
{
[super dealloc];
}
- (void) setUpQuestions
{
// create and init NSXMLParser object
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"query" ofType:@"xml"];
NSData *xml_data = [[NSData alloc] initWithContentsOfFile:filePath];
NSError *error;
GDataXMLDocument *xmlDoc = [[GDataXMLDocument alloc] initWithData:xml_data options:0 error:&error];
NSArray *rootDataArray = [xmlDoc.rootElement nodesForXPath:@"//query" error:nil];
for (GDataXMLElement *rootDataElement in rootDataArray)
{
// Allocate the query object
self->query = [[[Query alloc] init] autorelease];
// Name
NSArray *query_title = [rootDataElement elementsForName:@"text"];
if (query_title.count > 0)
{
GDataXMLElement *queryTitle = (GDataXMLElement *) [query_title objectAtIndex:0];
self->query.queryTitle = [[[NSString alloc] initWithString:queryTitle.stringValue] autorelease];
}
NSArray *query_first_question = [rootDataElement elementsForName:@"question"];
NSArray *replies = [NSArray alloc];
questions = [[NSMutableArray alloc] init];
if(query_first_question.count == 1)
{
GDataXMLElement *fq = (GDataXMLElement *) [query_first_question objectAtIndex:0];
replies = [fq elementsForName:@"reply"];
for (GDataXMLElement *replyElement in replies)
{
[questions addObject:replyElement];
}
}
}
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// Only one section.
return 1;
}
- (NSInteger) tableView: (UITableView *) tableView numberOfRowsInSection:(NSInteger)section
{
switch(section)
{
case 0:
return questions.count;
break;
case 1:
return 1;
break;
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = @"QuestionCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
cell.accessoryType = UITableViewCellAccessoryDetailDisclosureButton;
}
// Get the object to display and set the value in the cell.
GDataXMLElement *questionAtIndex = questions[indexPath.row];
NSString *cellText = [[[questionAtIndex elementsForName:@"text"] objectAtIndex:0] stringValue];
cell.textLabel.text = cellText;
//cell.textLabel.text = [[questionAtIndex elementsForName:@"text"] objectAtIndex:0];
return cell;
}
- (void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
//NSMutableString *msg = [NSMutableString new];
//[msg appendString:@"You selected row: "];
//[msg appendString:[NSString stringWithFormat:@"%i",indexPath.row]];
//UIAlertView *alertMsg = [[UIAlertView alloc] initWithTitle:@"Row Selected" message:msg delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
//[alertMsg show];
if (questions != nil)
{
GDataXMLElement *selectedReply = (GDataXMLElement *) [questions objectAtIndex:indexPath.row];
DetailViewController *dvc = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];
dvc.node = selectedReply;
[self.navigationController pushViewController:dvc animated:YES];
[dvc release];
}
}
编辑
我已经尝试分析和寻找僵尸，但是当崩溃发生时，没有标记僵尸对象。它在控制台中引发以下错误：
[UIView _forgetDependentConstraint:]: message sent to deallocated instance 0x1e8ab810