我正在创建一个实现自定义 UITableView 的应用程序。我这样做的方式如下:
我创建了一个 UINavigationController。这个 UINavigationController 推送一个实现 UITableViewDelegate 和 UITableViewDataSource 的 UIViewController。我为此 UIViewController 创建了一个 .xib,因此 UIViewController 有 3 个文件:TestTableViewController.h、TestTableViewController.m 和 TestTableViewController.xib。
TestTableViewController.xib 只有一个 UITableView 放置链接到一个名为 testTableView 的 IBOutlet UITableView,并且这个 UITableView 数据源和委托链接到文件的所有者(TestTableViewController)。
另外,我已经实现了自定义 UITableViewCell。我创建了一个名为 TestCell.xib 的空 .xib,我在其中放置了一个 UITableViewCell 并插入了一个 UIView、一个 UILabel、一个 UIImageView 和一个 UISwitch。然后我创建了一个继承自 UITableViewCell 的类,如下所示(我将 TestCell.xib 的视图定义为 TestCell 类并将标识符设置为 TestCellIdentifier):
测试细胞.h:
#import <UIKit/UIKit.h>
#define kTestHeight 40
@interface TestCell : UITableViewCell {
UIImageView *testImage;
UILabel *testLabel;
}
@property (nonatomic, retain) IBOutlet UIImageView *testImage;
@property (nonatomic, retain) IBOutlet UILabel *testLabel;
@end
测试单元.m:
#import "TestCell.h"
@implementation TestCell
@synthesize testImage, testLabel;
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
// Initialization code
}
return self;
}
- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
[super setSelected:selected animated:animated];
// Configure the view for the selected state
}
- (void)dealloc
{
[self.testLabel release];
[self.testImage release];
[super dealloc];
}
@end
我实现了所有的 TestTableViewController 如下:
测试表视图控制器.h:
#import <UIKit/UIKit.h>
@interface TestTableViewController : UIViewController <UITableViewDelegate, UITableViewDataSource> {
NSArray *labels;
NSArray *images;
UITableView *testTableView; // this is the UITableView linked in the NIB
}
@property (nonatomic, retain) NSArray *labels, *images;
@property (nonatomic, retain) IBOutlet UITableView *testTableView;
@end
测试表视图控制器.m:
#import "TestTableViewController.h"
#import "TestCell.h"
@implementation TestTableViewController
@synthesize labels, images;
@synthesize testTableView;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)dealloc
{
[self.labels release];
[self.images release];
[self.testTableView release];
[super dealloc];
}
- (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];
// Do any additional setup after loading the view from its nib.
self.title = @"Test";
self.labels = [[NSArray alloc] initWithObjects:
@"Test 1",
@"Test 2",
@"Test 3",
@"Test 4",
@"Test 5",
@"Test 6",
@"Test 7",
@"Test 8",
@"Test 9",
@"Test 10",
@"Test 11",
@"Test 12",
@"Test 13",
@"Test 14",
@"Test 15",
@"Test 16",
@"Test 17", nil];
self.images = [[NSArray alloc] initWithObjects:
[UIImage imageNamed:@"empty1.png"],
[UIImage imageNamed:@"empty2.png"],
[UIImage imageNamed:@"empty3.png"],
[UIImage imageNamed:@"empty4.png"],
[UIImage imageNamed:@"empty5.png"],
[UIImage imageNamed:@"empty6.png"],
[UIImage imageNamed:@"empty7.png"],
[UIImage imageNamed:@"empty8.png"],
[UIImage imageNamed:@"empty9.png"],
[UIImage imageNamed:@"empty10.png"],
[UIImage imageNamed:@"empty11.png"],
[UIImage imageNamed:@"empty12.png"],
[UIImage imageNamed:@"empty13.png"],
[UIImage imageNamed:@"empty14.png"],
[UIImage imageNamed:@"empty15.png"],
[UIImage imageNamed:@"empty16.png"],
[UIImage imageNamed:@"empty17.png"], nil];
self.testTableView.separatorColor = [UIColor colorWithRed:0 green:0.21 blue:0.43 alpha:1];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
self.labels = nil;
self.images = nil;
self.testTableView = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark - Table view data source methods
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
// Return the cell's height
return kTestCellHeight;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [self.labels count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *TestCellIdentifier = @"TestCellIdentifier";
TestCell *cell = (TestCell *)[tableView dequeueReusableCellWithIdentifier:TestCellIdentifier];
if (cell == nil) {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"TestCell"
owner:self
options:nil];
for (id oneObject in nib) {
if ([oneObject isKindOfClass:[TestCell class]]) {
cell = (TestCell *)oneObject;
}
}
}
NSInteger row = [indexPath row];
cell.testLabel.text = [self.labels objectAtIndex:row];
cell.testImage.image = [self.images objectAtIndex:row];
return cell;
}
@end
我想这就是所需上下文的所有描述。现在的问题。当我将表中的一个开关设置为 OFF(默认情况下它们为 ON)然后向下滚动然后再次向上滚动时,表开始将随机开关调整为 OFF 和 ON。这一切都非常随意。
任何人都知道为什么会发生这种情况或如何避免它?