UITableViewCell（s）在滚动时用其他图像覆盖默认图像 [英] UITableViewCell(s) with default image overwritten with other images upon scrolling
本文介绍了UITableViewCell（s）在滚动时用其他图像覆盖默认图像的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
- （UITableViewCell *）tableView：（UITableView *）tableView cellForRowAtIndexPath：（NSIndexPath *）indexPath
{
ReminderClass * reminderToDisplay = [self.remindersArray objectAtIndex：indexPath.row] ;
UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier：kCellIdentifier];
//现在创建单元格以显示数据
if（cell == nil）
{
cell = [[[UITableViewCell alloc] initWithStyle：UITableViewCellStyleDefault reuseIdentifier ：kCellIdentifier] autorelease];
cell.textLabel.lineBreakMode = UILineBreakModeWordWrap;
cell.textLabel.numberOfLines = 0;
cell.textLabel.font = [UIFont fontWithName：kHelvetica size：17.0];
cell.textLabel.adjustsFontSizeToFitWidth = YES;
cell.backgroundColor = [UIColor clearColor];
}
......
if（Image！= nil）
{
UIImageView * imageView = [[UIImageView alloc] initWithFrame：CGRectMake（240,3,70,63）];
imageView.backgroundColor = [UIColor clearColor];
[imageView setImage：Image];
cell.accessoryView = imageView;
[imageView发布];
}
其他
{
UIImageView * imageView = [[UIImageView alloc] initWithFrame：CGRectMake（240,3,70,63）];
imageView.backgroundColor = [UIColor clearColor];
UIImage * defaultImage = [UIImage imageNamed：kDefaultImage];
[imageView setImage：defaultImage];
cell.accessoryView = imageView;
[imageView发布];
}
cell.textLabel.text = reminderDetailsString;
返回单元格;
}
任何人都可以帮助我，提前谢谢：）
解决方案
只需将 dequeueReusableCellWithIdentifier 设置为 nil 以及 reuseIdentifier 到 nil 如下... ..
UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier：nil];
和
cell = [[[UITableViewCell alloc] initWithStyle：UITableViewCellStyleDefault reuseIdentifier：nil] autorelease];
并在此中添加您的其他代码if（cell == nil） if condition ..
更新：
- （UITableViewCell *）tableView：（UITableView *）tableView cellForRowAtIndexPath：（NSIndexPath *）indexPath {
NSString * CellIdentifier = [NSString stringWithFormat：@Cell％d％d， indexPath.section，indexPath.row];
if（cell == nil）{
cell = [[[UITableViewCell alloc] initWithStyle：UITableViewCellStyleValue1 reuseIdentifier：CellIdentifier] autorelease];
cell.textLabel.lineBreakMode = UILineBreakModeWordWrap;
cell.textLabel.numberOfLines = 0;
cell.textLabel.font = [UIFont fontWithName：kHelvetica size：17.0];
cell.textLabel.adjustsFontSizeToFitWidth = YES;
cell.backgroundColor = [UIColor clearColor];
tableView.backgroundColor = [UIColor clearColor];
NSDateFormatter * dateFormat = [[[NSDateFormatter alloc] init] autorelease];
[dateFormat setDateFormat：kDateFormat];
NSDate * reminderDate = [dateFormat dateFromString：reminderToDisplay.Date];
[dateFormat setDateFormat：kMinDateFormat];
NSString * dateString = [dateFormat stringFromDate：reminderDate];
NSString * valueString = [NSString stringWithFormat：kNameEvent，reminderToDisplay.Name，reminderToDisplay.Event];
NSString * onString = [NSString stringWithFormat：kOn，dateString];
NSString * reminderDetailsString = [valueString stringByAppendingString：onString];
ABAddressBookRef addressbook = ABAddressBookCreate（）;
CFArrayRef allPeople = ABAddressBookCopyArrayOfAllPeople（addressbook）;
CFIndex numPeople = ABAddressBookGetPersonCount（addressbook）;
for（int i = 0; i< numPeople; i ++）
{
ABRecordRef person = CFArrayGetValueAtIndex（allPeople，i）;
NSString * firstName =（NSString *）ABRecordCopyValue（person，kABPersonFirstNameProperty）;
NSString * lastName =（NSString *）ABRecordCopyValue（person，kABPersonLastNameProperty）;
NSMutableDictionary * contactsDictionary = [[[NSMutableDictionary alloc] init] autorelease];
if（firstName！= nil&& firstName！= NULL）
{
[contactsDictionary setObject：firstName forKey：kFirstName];
CFRelease（firstName）;
}
else
{
[contactsDictionary setObject：@forKey：kFirstName];
}
if（lastName！= nil&& lastName！= NULL）
{
[contactsDictionary setObject：lastName forKey：kLastName];
CFRelease（lastName）;
}
else
{
[contactsDictionary setObject：@forKey：kLastName];
}
//获取添加到dict的名字和姓氏，并将其组合成联系人姓名
firstName = [[[NSString alloc] initWithString：[contactsDictionary objectForKey： kFirstName]自动释放];
lastName = [NSString stringWithFormat：@％@，[contactsDictionary objectForKey：kLastName]];
self.contactName = [firstName stringByAppendingString：lastName];
//现在检查联系人姓名是否与提醒ToDisplay.Name相同
if（[reminderToDisplay.Name isEqualToString：contactName]&& ABPersonHasImageData（person））
{
CFDataRef imageData = ABPersonCopyImageData（person）;
self.reminderImage = [UIImage imageWithData：（NSData *）imageData];
CFRelease（imageData）;
}
}
CFRelease（allPeople）;
CFRelease（地址簿）;
if（[reminderToDisplay.reminderGroup isEqualToString：kFacebook]）
{
NSString * imageName = [NSString stringWithFormat：kImageName，reminderToDisplay.Name];
NSArray * paths = NSSearchPathForDirectoriesInDomains（NSDocumentDirectory，NSUserDomainMask，YES）;
NSString * documentsDirectory = [paths objectAtIndex：0];
NSString * reminderString = [documentsDirectory stringByAppendingPathComponent：[NSString stringWithString：imageName]];
self.reminderImage = [UIImage imageWithContentsOfFile：reminderString];
}
if（reminderImage！= nil）
{
UIImageView * imageView = [[UIImageView alloc] initWithFrame：CGRectMake（240,3,70,63） ]。
imageView.backgroundColor = [UIColor clearColor];
[imageView setImage：reminderImage];
cell.accessoryView = imageView;
[imageView发布];
}
其他
{
UIImageView * imageView = [[UIImageView alloc] initWithFrame：CGRectMake（240,3,70,63）];
imageView.backgroundColor = [UIColor clearColor];
UIImage * defaultImage = [UIImage imageNamed：kDefaultImage];
[imageView setImage：defaultImage];
cell.accessoryView = imageView;
[imageView发布];
}
cell.textLabel.text = reminderDetailsString;
}
返回单元格;
}
Oops,I am facing an issue with table view cells having no image,i.e. the cell with default image.Upon scrolling the default image disappears and some image from a cell is appearing on it.I have implemented the suggestion from Mr.Rckoenes here .Even then I was unable to fix the issue.Here is my implementation code for understanding:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
ReminderClass *reminderToDisplay = [self.remindersArray objectAtIndex:indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:kCellIdentifier];
// Now create the cell to display the data
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:kCellIdentifier] autorelease];
cell.textLabel.lineBreakMode = UILineBreakModeWordWrap;
cell.textLabel.numberOfLines = 0;
cell.textLabel.font = [UIFont fontWithName:kHelvetica size:17.0];
cell.textLabel.adjustsFontSizeToFitWidth = YES;
cell.backgroundColor = [UIColor clearColor];
}
......
if (Image != nil)
{
UIImageView *imageView=[[UIImageView alloc] initWithFrame:CGRectMake(240, 3, 70, 63)];
imageView.backgroundColor=[UIColor clearColor];
[imageView setImage:Image];
cell.accessoryView = imageView;
[imageView release];
}
else
{
UIImageView *imageView=[[UIImageView alloc] initWithFrame:CGRectMake(240, 3, 70, 63)];
imageView.backgroundColor=[UIColor clearColor];
UIImage *defaultImage = [UIImage imageNamed:kDefaultImage];
[imageView setImage:defaultImage];
cell.accessoryView = imageView;
[imageView release];
}
cell.textLabel.text = reminderDetailsString;
return cell;
}
Can any one please help me,thanks in advance :)
解决方案
just set dequeueReusableCellWithIdentifier to nil and also reuseIdentifier to nil like bellow..
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:nil];
and
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil] autorelease];
and also add your other code in this if (cell == nil) if condition..
UPDATE:
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSString *CellIdentifier = [NSString stringWithFormat:@"Cell%d%d",indexPath.section,indexPath.row];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
cell.textLabel.lineBreakMode = UILineBreakModeWordWrap;
cell.textLabel.numberOfLines = 0;
cell.textLabel.font = [UIFont fontWithName:kHelvetica size:17.0];
cell.textLabel.adjustsFontSizeToFitWidth = YES;
cell.backgroundColor = [UIColor clearColor];
tableView.backgroundColor = [UIColor clearColor];
NSDateFormatter *dateFormat = [[[NSDateFormatter alloc]init]autorelease];
[dateFormat setDateFormat:kDateFormat];
NSDate *reminderDate = [dateFormat dateFromString:reminderToDisplay.Date];
[dateFormat setDateFormat:kMinDateFormat];
NSString *dateString = [dateFormat stringFromDate:reminderDate];
NSString *valueString = [NSString stringWithFormat:kNameEvent,reminderToDisplay.Name,reminderToDisplay.Event];
NSString *onString = [NSString stringWithFormat:kOn,dateString];
NSString *reminderDetailsString = [valueString stringByAppendingString:onString];
ABAddressBookRef addressbook = ABAddressBookCreate();
CFArrayRef allPeople = ABAddressBookCopyArrayOfAllPeople(addressbook);
CFIndex numPeople = ABAddressBookGetPersonCount(addressbook);
for (int i=0; i < numPeople; i++)
{
ABRecordRef person = CFArrayGetValueAtIndex(allPeople, i);
NSString *firstName=(NSString *)ABRecordCopyValue(person, kABPersonFirstNameProperty);
NSString *lastName=(NSString *)ABRecordCopyValue(person, kABPersonLastNameProperty);
NSMutableDictionary *contactsDictionary = [[[NSMutableDictionary alloc]init]autorelease];
if(firstName != nil && firstName != NULL)
{
[contactsDictionary setObject:firstName forKey:kFirstName];
CFRelease(firstName);
}
else
{
[contactsDictionary setObject:@"" forKey:kFirstName];
}
if(lastName != nil && lastName != NULL)
{
[contactsDictionary setObject:lastName forKey:kLastName];
CFRelease(lastName);
}
else
{
[contactsDictionary setObject:@"" forKey:kLastName];
}
//Get the first name and last name added to dict and combine it to form contact name
firstName = [[[NSString alloc]initWithString:[contactsDictionary objectForKey:kFirstName]]autorelease];
lastName = [NSString stringWithFormat:@" %@",[contactsDictionary objectForKey:kLastName]];
self.contactName = [firstName stringByAppendingString:lastName];
//Now check whether the contact name is same as your reminderToDisplay.Name
if([reminderToDisplay.Name isEqualToString:contactName] && ABPersonHasImageData(person))
{
CFDataRef imageData = ABPersonCopyImageData(person);
self.reminderImage = [UIImage imageWithData:(NSData *)imageData];
CFRelease(imageData);
}
}
CFRelease(allPeople);
CFRelease(addressbook);
if ([reminderToDisplay.reminderGroup isEqualToString:kFacebook])
{
NSString *imageName = [NSString stringWithFormat:kImageName,reminderToDisplay.Name];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *reminderString=[documentsDirectory stringByAppendingPathComponent:[NSString stringWithString:imageName]];
self.reminderImage = [UIImage imageWithContentsOfFile:reminderString];
}
if (reminderImage != nil)
{
UIImageView *imageView=[[UIImageView alloc] initWithFrame:CGRectMake(240, 3, 70, 63)];
imageView.backgroundColor=[UIColor clearColor];
[imageView setImage:reminderImage];
cell.accessoryView = imageView;
[imageView release];
}
else
{
UIImageView *imageView=[[UIImageView alloc] initWithFrame:CGRectMake(240, 3, 70, 63)];
imageView.backgroundColor=[UIColor clearColor];
UIImage *defaultImage = [UIImage imageNamed:kDefaultImage];
[imageView setImage:defaultImage];
cell.accessoryView = imageView;
[imageView release];
}
cell.textLabel.text = reminderDetailsString;
}
return cell;
}
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