我有一些朋友的名字的文件列表。我想了解UITableViewNavigation。我从一个文件加载列表,但是当我选择一个单元格时,数据数组在那一点上似乎是空的,我无法弄清楚为什么。
在该方法我得到这个错误
为什么在选择UITableView单元时NSArray为空?
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
FriendsNameViewController *newView =[[FriendsNameViewController alloc] initWithNibName:@"FriendsNameViewController" bundle:nil];
[self.navigationController pushViewController:newView animated:YES];
//Crashes here
NSString *temp = [dataArray objectAtIndex:indexPath.row];
NSLog(@"%@",temp);
[[newView labelx] setText:[NSString stringWithFormat: @"%@" ,temp]];
}
2011-10-03 14:43:08.411 navman2 [69691:B303] *终止应用程序由于 未捕获的异常' NSRangeException',原因:'* - [NSMutableArray objectAtIndex:]:索引2超出空数组的界限'
接口
#import <UIKit/UIKit.h>
@interface TableViewController : UITableViewController
{
NSArray *dataArray;
}
@property(retain,nonatomic) NSArray *dataArray;
@end
然后implementaion这里
#import "TableViewController.h"
#import "FriendsNameViewController.h"
@implementation TableViewController
@synthesize dataArray;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"myfriendsList" ofType:@"txt"];
NSStringEncoding encoding;
NSError* error;
NSString* fh = [NSString stringWithContentsOfFile:filePath usedEncoding:&encoding error:&error];
dataArray = [NSArray alloc];
dataArray = [fh componentsSeparatedByString:@"\n"];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
}
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [dataArray count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell...
cell.textLabel.text = [dataArray objectAtIndex:indexPath.row];
return cell;
}
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
FriendsNameViewController *newView =[[FriendsNameViewController alloc] initWithNibName:@"FriendsNameViewController" bundle:nil];
[self.navigationController pushViewController:newView animated:YES];
//Crashes here
NSString *temp = [dataArray objectAtIndex:indexPath.row];
NSLog(@"%@",temp);
[[newView labelx] setText:[NSString stringWithFormat: @"%@" ,temp]];
}
@end
将'viewDidunload'中的代码更改为'self.dataArray = [NSMutableArray alloc];' 'self.dataArray = [fh componentsSeparatedByString:@“\ n”];'修复了它,但我没有得到区别。知道它与Autorelease有关,但是自我产生了什么差别。 –