我有UITableView显示信息，但大多数我坚持的位显示星级评分。我设法创建了一个自定义UITableViewCell，其中包含显示每个单元格的星级评分的逻辑。因此，如果等级为3，它将显示3颗黄色星和2个空白星，因此总共得到5分。当显示UITableView时，我可以看到前4个单元格的星级评分是正确的：
仅显示TEN细胞。
Rating in order of cell (what comes back from the Database):
5
3
3
1
0
0
0
0
0
0
但最新发生的是，当我滚动细胞时，我得到了这些评级，似乎重复了第一个细胞评级：
Rating in order of cell when scrolled (UI Scrolling):
5
3
3
1
5
3
3
1
5
3
为什么会这样？
如果需要，我会给你代码和编辑。
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if(tableView == tableViewTopThreads){
static NSString *simpleTableIdentifier = @"SimpleTableItem";
ThreadTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
//cell.layer.shouldRasterize = YES;
//cell.layer.rasterizationScale = [UIScreen mainScreen].scale;
if (cell == nil) {
cell = [[ThreadTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
}
Thread *t = (Thread*)[tmpArray4 objectAtIndex:indexPath.row];
cell.labelTitle.text = t.title;
cell.labelCat.text = t.cat;
cell.labelUser.text = [NSString stringWithFormat:@"%@ %@", t.firstname, t.lastname];
cell.labelDate.text = [NSString stringWithFormat:@"%@", t.date];
cell.labelCountry.text = t.country;
cell.labelSubCat.text = t.subcat;
cell.rating = t.rating;
[cell.contentView setNeedsUpdateConstraints];
[cell.contentView updateConstraintsIfNeeded];
[cell.contentView setNeedsLayout];
[cell.contentView layoutIfNeeded];
return cell;
}
}
自定义单元格：
#import "ThreadTableViewCell.h"
@implementation ThreadTableViewCell
@synthesize main;
@synthesize top;
@synthesize center;
@synthesize bottom;
@synthesize rate;
@synthesize rating;
@synthesize labelTitle;
@synthesize labelCat;
@synthesize labelSubCat;
@synthesize labelUser;
@synthesize labelDate;
@synthesize labelCountry;
@synthesize imageviewThreadImage;
@synthesize imageviewRating1;
@synthesize imageviewRating2;
@synthesize imageviewRating3;
@synthesize imageviewRating4;
@synthesize imageviewRating5;
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier {
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
//self.contentView.backgroundColor = [UIColor lightGrayColor];
[self.contentView setTranslatesAutoresizingMaskIntoConstraints:NO];
self.contentView.autoresizingMask = UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth;
//CGRect screenBound = [[UIScreen mainScreen] bounds];
//CGSize screenSize = screenBound.size;
//CGFloat screenWidth = screenSize.width;
//CGFloat screenHeight = screenSize.height;
main = [UIView new];
[self.contentView addSubview:main];
main.translatesAutoresizingMaskIntoConstraints = NO;
//[main sizeToFit];
main.backgroundColor = [UIColor whiteColor];
top = [UIView new];
[main addSubview:top];
top.translatesAutoresizingMaskIntoConstraints = NO;
//[top sizeToFit];
top.backgroundColor = [UIColor whiteColor];
labelUser = [UILabel new];
[top addSubview:labelUser];
labelUser.translatesAutoresizingMaskIntoConstraints = NO;
//[labelUser sizeToFit];
[labelUser setFont:[UIFont systemFontOfSize:14]];
labelUser.textColor = [UIColor colorWithRed:(114.0/255.0) green:(114.0/255.0) blue:(114.0/255.0) alpha:1.0];
labelDate = [UILabel new];
[top addSubview:labelDate];
labelDate.translatesAutoresizingMaskIntoConstraints = NO;
[labelDate sizeToFit];
[labelDate setFont:[UIFont systemFontOfSize:14]];
labelDate.textColor = [UIColor colorWithRed:(114.0/255.0) green:(114.0/255.0) blue:(114.0/255.0) alpha:1.0];
center = [UIView new];
[main addSubview:center];
center.translatesAutoresizingMaskIntoConstraints = NO;
[center sizeToFit];
center.backgroundColor = [UIColor whiteColor];
imageviewThreadImage = [UIImageView new];
[center addSubview:imageviewThreadImage];
imageviewThreadImage.translatesAutoresizingMaskIntoConstraints = NO;
imageviewThreadImage.backgroundColor = [UIColor colorWithRed:(207.0/255.0) green:(215.0/255.0) blue:(248.0/255.0) alpha:1.0];
labelTitle = [UILabel new];
[center addSubview:labelTitle];
labelTitle.translatesAutoresizingMaskIntoConstraints = NO;
[labelTitle sizeToFit];
labelTitle.lineBreakMode = NSLineBreakByWordWrapping;
[labelTitle setFont:[UIFont systemFontOfSize:14]];
labelTitle.textColor = [UIColor lightGrayColor];
labelTitle.numberOfLines = 0;
//labelTitle.preferredMaxLayoutWidth = screenWidth - 10 - 36;
bottom = [UIView new];
[main addSubview:bottom];
bottom.translatesAutoresizingMaskIntoConstraints = NO;
[bottom sizeToFit];
labelCat = [UILabel new];
[bottom addSubview:labelCat];
labelCat.translatesAutoresizingMaskIntoConstraints = NO;
[labelCat sizeToFit];
[labelCat setFont:[UIFont systemFontOfSize:12]];
labelCat.textColor = [UIColor colorWithRed:(58.0/255.0) green:(82.0/255.0) blue:(207.0/255.0) alpha:1.0];
labelSubCat = [UILabel new];
[bottom addSubview:labelSubCat];
labelSubCat.translatesAutoresizingMaskIntoConstraints = NO;
[labelSubCat sizeToFit];
[labelSubCat setFont:[UIFont systemFontOfSize:12]];
labelSubCat.textColor = [UIColor colorWithRed:(58.0/255.0) green:(82.0/255.0) blue:(207.0/255.0) alpha:1.0];
labelCountry = [UILabel new];
[bottom addSubview:labelCountry];
labelCountry.translatesAutoresizingMaskIntoConstraints = NO;
[labelCountry sizeToFit];
[labelCountry setFont:[UIFont systemFontOfSize:12]];
labelCountry.textColor = [UIColor colorWithRed:(58.0/255.0) green:(82.0/255.0) blue:(207.0/255.0) alpha:1.0];
rate = [UIView new];
[bottom addSubview:rate];
rate.translatesAutoresizingMaskIntoConstraints = NO;
[rate sizeToFit];
imageviewRating1 = [UIImageView new];
[rate addSubview:imageviewRating1];
imageviewRating1.translatesAutoresizingMaskIntoConstraints = NO;
[imageviewRating1 sizeToFit];
imageviewRating2 = [UIImageView new];
[rate addSubview:imageviewRating2];
imageviewRating2.translatesAutoresizingMaskIntoConstraints = NO;
[imageviewRating2 sizeToFit];
imageviewRating3 = [UIImageView new];
[rate addSubview:imageviewRating3];
imageviewRating3.translatesAutoresizingMaskIntoConstraints = NO;
[imageviewRating3 sizeToFit];
imageviewRating4 = [UIImageView new];
[rate addSubview:imageviewRating4];
imageviewRating4.translatesAutoresizingMaskIntoConstraints = NO;
[imageviewRating4 sizeToFit];
imageviewRating5 = [UIImageView new];
[rate addSubview:imageviewRating5];
imageviewRating5.translatesAutoresizingMaskIntoConstraints = NO;
[imageviewRating5 sizeToFit];
UIImage *imageStarDisabled = [UIImage imageNamed:@"star.png"];
//UIImage *imageStarEnabled = [UIImage imageNamed:@"star2.png"];
imageviewRating1.image = imageStarDisabled;
imageviewRating2.image = imageStarDisabled;
imageviewRating3.image = imageStarDisabled;
imageviewRating4.image = imageStarDisabled;
imageviewRating5.image = imageStarDisabled;
}
return self;
}
- (void)layoutSubviews
{
[super layoutSubviews];
// Make sure the contentView does a layout pass here so that its subviews have their frames set, which we
// need to use to set the preferredMaxLayoutWidth below.
[self.contentView setNeedsLayout];
[self.contentView layoutIfNeeded];
// Set the preferredMaxLayoutWidth of the mutli-line bodyLabel based on the evaluated width of the label's frame,
// as this will allow the text to wrap correctly, and as a result allow the label to take on the correct height.
self.labelTitle.preferredMaxLayoutWidth = CGRectGetWidth(self.labelTitle.frame);
}
- (void)updateConstraints {
[super updateConstraints];
if (self.didSetupConstraints) return;
//UIImage *imageStarDisabled = [UIImage imageNamed:@"star.png"];
UIImage *imageStarEnabled = [UIImage imageNamed:@"star2.png"];
if(rating > 0){
for(int i = 1; i < rating + 1; i++){
if(i == 1){
imageviewRating1.image = imageStarEnabled;
}
if (i == 2) {
imageviewRating2.image = imageStarEnabled;
}
if (i == 3) {
imageviewRating3.image = imageStarEnabled;
}
if (i == 4) {
imageviewRating4.image = imageStarEnabled;
}
if (i == 5) {
imageviewRating5.image = imageStarEnabled;
}
}
}
NSDictionary *viewsDictionary7 = @{@"main":main};
NSArray *constraint_H37 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[main]|"
options:0
metrics:nil
views:viewsDictionary7];
NSArray *constraint_V37 = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|[main]|"
options:0
metrics:nil
views:viewsDictionary7];
[self.contentView addConstraints:constraint_H37];
[self.contentView addConstraints:constraint_V37];
NSDictionary *viewsDictionary3 = @{@"top":top,@"center":center,@"bottom":bottom};
NSArray *constraint_H3 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-5-[top]-5-[center]-5-[bottom]-10-|"
options:0
metrics:nil
views:viewsDictionary3];
NSArray *constraint_H33 = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|[top]|"
options:0
metrics:nil
views:viewsDictionary3];
NSArray *constraint_H333 = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|[center]|"
options:0
metrics:nil
views:viewsDictionary3];
NSArray *constraint_H3335657 = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|[bottom]|"
options:0
metrics:nil
views:viewsDictionary3];
NSDictionary *viewsDictionary4 = @{@"labelUser":labelUser,@"labelDate":labelDate};
NSArray *constraint_H4 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[labelUser]|"
options:0
metrics:nil
views:viewsDictionary4];
NSDictionary *viewsDictionary45 = @{@"labelDate":labelDate};
NSArray *constraint_H4555 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[labelDate]|"
options:0
metrics:nil
views:viewsDictionary45];
NSArray *constraint_H44 = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-5-[labelUser]-20-[labelDate]-5-|"
options:0
metrics:nil
views:viewsDictionary4];
NSDictionary *viewsDictionary48 = @{@"labelTitle":labelTitle,@"imageviewThreadImage":imageviewThreadImage};
NSArray *constraint_H48 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[labelTitle]|"
options:0
metrics:nil
views:viewsDictionary48];
NSArray *constraint_H48342 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-8-[imageviewThreadImage(36)]|"
options:0
metrics:nil
views:viewsDictionary48];
NSArray *constraint_H448 = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-5-[imageviewThreadImage(36)]-5-[labelTitle]|"
options:0
metrics:nil
views:viewsDictionary48];
NSDictionary *viewsDictionary488 = @{@"labelCat":labelCat,@"labelCountry":labelCountry,@"labelSubCat":labelSubCat,@"rate":rate};
NSArray *constraint_H488 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-5-[labelCat]|"
options:0
metrics:nil
views:viewsDictionary488];
NSArray *constraint_H48898 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-5-[labelCountry]|"
options:0
metrics:nil
views:viewsDictionary488];
NSArray *constraint_H48898fgf54 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-5-[labelSubCat]|"
options:0
metrics:nil
views:viewsDictionary488];
NSArray *constraint_H48898fgf54fdf = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-5-[rate]|"
options:0
metrics:nil
views:viewsDictionary488];
NSArray *constraint_H4488 = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-5-[labelCat]-10-[labelSubCat]-10-[labelCountry]-10-[rate]"
options:0
metrics:nil
views:viewsDictionary488];
NSDictionary *viewsDictionary4885 = @{@"imageviewRating1":imageviewRating1,@"imageviewRating2":imageviewRating2,@"imageviewRating3":imageviewRating3,@"imageviewRating4":imageviewRating4,@"imageviewRating5":imageviewRating5};
NSArray *constraint_H488fbfb = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[imageviewRating1(15)]|"
options:0
metrics:nil
views:viewsDictionary4885];
NSArray *constraint_H48898xfb = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[imageviewRating2(15)]|"
options:0
metrics:nil
views:viewsDictionary4885];
NSArray *constraint_H48898xfbfg = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[imageviewRating3(15)]|"
options:0
metrics:nil
views:viewsDictionary4885];
NSArray *constraint_H48898xfbxfg = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[imageviewRating4(15)]|"
options:0
metrics:nil
views:viewsDictionary4885];
NSArray *constraint_H48898xfrtbxfg = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[imageviewRating5(15)]|"
options:0
metrics:nil
views:viewsDictionary4885];
NSArray *constraint_H48898fgf54fxb = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|[imageviewRating1(15)]-2-[imageviewRating2(15)]-2-[imageviewRating3(15)]-2-[imageviewRating4(15)]-2-[imageviewRating5(15)]"
options:0
metrics:nil
views:viewsDictionary4885];
[main addConstraints:constraint_H3];
[main addConstraints:constraint_H33];
[main addConstraints:constraint_H333];
[top addConstraints:constraint_H4];
[top addConstraints:constraint_H44];
[center addConstraints:constraint_H48];
[center addConstraints:constraint_H448];
[top addConstraints:constraint_H4555];
[main addConstraints:constraint_H3335657];
[main addConstraints:constraint_H488];
[main addConstraints:constraint_H4488];
[main addConstraints:constraint_H48898];
[main addConstraints:constraint_H48342];
[main addConstraints:constraint_H48898fgf54];
[main addConstraints:constraint_H48898fgf54fdf];
[bottom addConstraints:constraint_H488fbfb];
[bottom addConstraints:constraint_H48898xfb];
[bottom addConstraints:constraint_H48898xfbfg];
[bottom addConstraints:constraint_H48898xfbxfg];
[bottom addConstraints:constraint_H48898xfrtbxfg];
[bottom addConstraints:constraint_H48898fgf54fxb];
self.didSetupConstraints = YES;
}
- (void)awakeFromNib {
// Initialization code
}
- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
[super setSelected:selected animated:animated];
// Configure the view for the selected state
}
@end
ViewController，用于设置数据库的评级：
dispatch_queue_t concurrentQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
// 3) Load picker in background
dispatch_async(concurrentQueue, ^{
NSString *myRequestString = [NSString stringWithFormat:@"threadTitle=%@&threadCountry=%@&threadCategory=%@&threadSubCategory=%@",searchThreadTitleTopThreads, searchThreadCountryTopThreads, searchThreadCategoryTopThreads, searchThreadSubCategoryTopThreads];
__block NSString *response = [self setupPhpCall:myRequestString :@"xxx.php"];
dispatch_async(dispatch_get_main_queue(), ^{
if(response.length > 0){
NSDictionary *dic = [response JSONValue];
if((NSNull*)dic != [NSNull null]){
int at_ID = 0;
int at_U_ID = 0;
int rating = 0;
NSString *at_Title;
NSString *at_Desc;
NSString *at_Cat;
NSString *at_SubCat;
NSString *at_Date;
NSString *at_Country;
NSString *at_FirstName;
NSString *at_LastName;
for(NSDictionary *dict in dic)
{
counter = counter + 1;
if((NSNull *)[dict objectForKey:@"AT_ID"] != [NSNull null]){
at_ID = [[dict objectForKey:@"AT_ID"] intValue];
}
if((NSNull *)[dict objectForKey:@"AT_U_ID"] != [NSNull null]){
at_U_ID = [[dict objectForKey:@"AT_U_ID"] intValue];
}
if((NSNull *)[dict objectForKey:@"AT_Title"] != [NSNull null]){
at_Title = [dict objectForKey:@"AT_Title"];
}
if((NSNull *)[dict objectForKey:@"AT_Desc"] != [NSNull null]){
at_Desc = [dict objectForKey:@"AT_Desc"];
}
if((NSNull *)[dict objectForKey:@"AT_Cat"] != [NSNull null]){
at_Cat = [dict objectForKey:@"AT_Cat"];
}
if((NSNull *)[dict objectForKey:@"AT_SubCat"] != [NSNull null]){
at_SubCat = [dict objectForKey:@"AT_SubCat"];
}
if((NSNull *)[dict objectForKey:@"AT_Country"] != [NSNull null]){
at_Country = [dict objectForKey:@"AT_Country"];
}
if((NSNull *)[dict objectForKey:@"U_FirstName"] != [NSNull null]){
at_FirstName = [dict objectForKey:@"U_FirstName"];
}
if((NSNull *)[dict objectForKey:@"U_LastName"] != [NSNull null]){
at_LastName = [dict objectForKey:@"U_LastName"];
}
if((NSNull *)[dict objectForKey:@"AVG(r.TR_Value)"] != [NSNull null]){
rating = [[dict objectForKey:@"AVG(r.TR_Value)"] intValue];
}
NSString *dateTS = [dict objectForKey:@"AT_Date"];
if((NSNull *)[dict objectForKey:@"AT_Date2"] != [NSNull null]){
NSString *timestampString = [dict objectForKey:@"AT_Date2"];
double timestampDate = [timestampString doubleValue];
NSDate *d = [NSDate dateWithTimeIntervalSince1970:timestampDate];
NSDateFormatter *_formatter=[[NSDateFormatter alloc]init];
[_formatter setDateFormat:@"dd.MM.yyyy HH:mm:ss"];
at_Date = [_formatter stringFromDate:d];
if (counter == 1) {
//lastDateForumActivity = dateTS;
}
}
if(counter == 1){
//lastDateForumActivity = dateTS;
}
Thread *thread = [[Thread alloc] init];
thread.tag = at_ID;
thread.idUser = at_U_ID;
thread.firstname = at_FirstName;
thread.lastname = at_LastName;
thread.idThread = at_ID;
thread.title = at_Title;
thread.desc = at_Desc;
thread.cat = at_Cat;
thread.date = at_Date;
thread.country = at_Country;
thread.subcat = at_SubCat;
thread.rating = rating; //RATING SET
[tmpArray4 addObject:thread];
//cell = nil;
}
at_ID = 0;
at_U_ID = 0;
at_Title = @"";
at_Desc = @"";
at_Cat = @"";
at_Date = @"";
at_Country = @"";
at_FirstName = @"";
at_LastName = @"";
}
}
答案 0 :(得分：1)
您的问题在于您不会考虑重复使用的单元格。由于单元格被重复使用，单元格的初始化会将图像设置为禁用的星形，但在代码中正确设置星形，您只需将它们切换为启用的星形图像。如果当前单元格的等级为0，则永远不会将它们设置回来，但是它被应用于等级为3的重用单元格。因此，您的代码不会更改任何图像，因此3个已启用的星形图像会保持。
为rating属性添加一个setter，类似于此。此外，从Xcode 4.4开始，不需要@synthesize，所以你可以摆脱它。
- (void)setRating: (int)newRatingValue {
_rating = newRatingValue;
UIImage *imageStarDisabled = [UIImage imageNamed:@"star.png"];
UIImage *imageStarEnabled = [UIImage imageNamed:@"star2.png"];
imageviewRating1.image = rating >= 1 ? imageStarEnabled : imageStarDisabled;
imageviewRating2.image = rating >= 2 ? imageStarEnabled : imageStarDisabled;
imageviewRating3.image = rating >= 3 ? imageStarEnabled : imageStarDisabled;
imageviewRating4.image = rating >= 4 ? imageStarEnabled : imageStarDisabled;
imageviewRating5.image = rating >= 5 ? imageStarEnabled : imageStarDisabled;
}
我相信下面的内容会有效，但如果你在后台线程上更新评级，可能会导致一些问题。您可能需要在调度异步调用中包装更新图像，以便在主（UI）线程上执行它，如下所示：
dispatch_async( dispatch_get_main_queue(), ^{
imageviewRating1.image = rating >= 1 ? imageStarEnabled : imageStarDisabled;
imageviewRating2.image = rating >= 2 ? imageStarEnabled : imageStarDisabled;
imageviewRating3.image = rating >= 3 ? imageStarEnabled : imageStarDisabled;
imageviewRating4.image = rating >= 4 ? imageStarEnabled : imageStarDisabled;
imageviewRating5.image = rating >= 5 ? imageStarEnabled : imageStarDisabled;
});`
此外，您应该学习如何使用调试器来放置断点并逐步执行代码，检查事物的状态。这将有助于将来解决和诊断这些类型的问题。
答案 1 :(得分：0)
我把你的逻辑移到了@wottle：
CardView这是放置逻辑的最佳位置吗？