[英]How to increase the label and cell size on clicking a button in a TableViewCell.
我想在單元格上單擊seeMoreBtn后展開單元格大小。
標簽和單元格具有不同的長度,但它們是標簽大小的約束。
當狀態太大時,我添加了一個seeMoreBtn,點擊后查看更多剩余文本將在下面顯示,然后如何增加標簽和單元格大小。
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;
{
NSString *text = [items objectAtIndex:[indexPath row]];
CGSize constraint = CGSizeMake(300.0f, 150.0f);
CGSize size = [text sizeWithFont:[UIFont systemFontOfSize:14.0f] constrainedToSize:constraint lineBreakMode:NSLineBreakByCharWrapping];
CGFloat height1 = MAX(size.height, 44.0f);
return height1 + (40.0f);
}
- (UITableViewCell *)tableView:(UITableView *)tv cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *CellIdentifier = [NSString stringWithFormat:@"Cell-%d",indexPath.row];
cell=[tv dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell=[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
int lbltag = 1000;
label=[[UILabel alloc]initWithFrame:CGRectZero];
[label setLineBreakMode:NSLineBreakByWordWrapping];
[label setMinimumScaleFactor:14.0f];
[label setNumberOfLines:0];
[label setFont:[UIFont systemFontOfSize:14.0f]];
NSString *text = [items objectAtIndex:[indexPath row]];
[label setText:text];
label.tag = lbltag;
[cell addSubview:label];
CGSize constraint1=CGSizeMake(300.0f, 150.0f);
CGSize size1=[text sizeWithFont:[UIFont systemFontOfSize:14.0f] constrainedToSize:constraint1 lineBreakMode:NSLineBreakByWordWrapping];
[label setFrame:CGRectMake(10.0f, 10.0f, 300.0f, MAX(size1.height, 44.0f))];
int countText=text.length;
if (countText>=350) {
seeMoreBtn=[UIButton buttonWithType:UIButtonTypeRoundedRect];
[seeMoreBtn setTitle:@"See More" forState:UIControlStateNormal];
seeMoreBtn.frame=CGRectMake(220.0f, MAX(size1.height, 44.0f)-10, 80.0f, 20.0f);
seeMoreBtn.tag=indexPath.row ;
[seeMoreBtn addTarget:self action:@selector(increaseSize:) forControlEvents:UIControlEventTouchUpInside];
[cell addSubview:seeMoreBtn];
}
return cell;
}
-(void)increaseSize:(UIButton *)sender{
//What to write here that can adjust the label and cell size
}
如果您繼承UITableViewCell並使用layoutSubviews調整單元格的大小,那會更好。
//In SMTableViewCell.h
@interface SMTableViewCell : UITableViewCell
@property (weak, nonatomic) IBOutlet UILabel *statusLabel;
@property (weak, nonatomic) IBOutlet UIButton *seeMoreButton;
//SMTableViewCell.m
- (void)layoutSubviews
{
CGRect labelFrame = self.statusLabel.frame;
labelFrame.size.height = self.frame.size.height - 55.0f;
self.statusLabel.frame = labelFrame;
CGRect buttonFrame = self.seeMoreButton.frame;
buttonFrame.origin.y = labelFrame.origin.y+labelFrame.size.height+10.0f;
self.seeMoreButton.frame = buttonFrame;
}
保留一個數組來存儲selectedIndexPaths:
@property (nonatomic, strong) NSMutableArray *selectedIndexPaths;
計算單元格的高度:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;
{
BOOL isSelected = [self.selectedIndexPaths containsObject:indexPath];
CGFloat maxHeight = MAXFLOAT;
CGFloat minHeight = 40.0f;
CGFloat constrainHeight = isSelected?maxHeight:minHeight;
CGFloat constrainWidth = tableView.frame.size.width - 20.0f;
NSString *text = self.items[indexPath.row];
CGSize constrainSize = CGSizeMake(constrainWidth, constrainHeight);
CGSize labelSize = [text sizeWithFont:[UIFont systemFontOfSize:15.0f]
constrainedToSize:constrainSize
lineBreakMode:NSLineBreakByCharWrapping];
return MAX(labelSize.height+75, 100.0f);
}
初始化自定義顯示更多TableViewCell:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = @"CellIdentifier";
SMTableViewCell *cell= (SMTableViewCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil)
{
cell = [[[NSBundle mainBundle]loadNibNamed:NSStringFromClass([SMTableViewCell class])
owner:nil
options:nil] lastObject];
}
BOOL isSelected = [self.selectedIndexPaths containsObject:indexPath];
cell.statusLabel.numberOfLines = isSelected?0:2;
NSString *text = self.items[indexPath.row];
cell.statusLabel.text = text;
NSString *buttonTitle = isSelected?@"See Less":@"See More";
[cell.seeMoreButton setTitle:buttonTitle forState:UIControlStateNormal];
[cell.seeMoreButton addTarget:self action:@selector(seeMoreButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
[cell.seeMoreButton setTag:indexPath.row];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
return cell;
}
按鈕點擊事件方法:
- (void)seeMoreButtonPressed:(UIButton *)button
{
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:button.tag inSection:0];
[self addOrRemoveSelectedIndexPath:indexPath];
}
- (void)addOrRemoveSelectedIndexPath:(NSIndexPath *)indexPath
{
if (!self.selectedIndexPaths) {
self.selectedIndexPaths = [NSMutableArray new];
}
BOOL containsIndexPath = [self.selectedIndexPaths containsObject:indexPath];
if (containsIndexPath) {
[self.selectedIndexPaths removeObject:indexPath];
}else{
[self.selectedIndexPaths addObject:indexPath];
}
[self.tableView reloadRowsAtIndexPaths:@[indexPath]
withRowAnimation:UITableViewRowAnimationFade];
}
如果選擇了單元格,則會給出相同的事件:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
[self addOrRemoveSelectedIndexPath:indexPath];
}
示例演示項目鏈接。
添加如下屬性:
@property(strong, nonatomic) NSArray *enlargedIndexPaths;
將其初始化為空數組。 實現表視圖委托:
- (CGFloat)tableView:(UITableView*)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return ([self.enlargedIndexPaths containsObject:indexPath])? 88.0 : 44.0;
}
然后在increaseSize中:
UITableViewCell *cell = sender.superview;
NSIndexPath *indexPath = [self.tableView indexPathFoCell:cell];
[self.enlargedIndexPaths addObject:indexPath];
// do you want to enlarge more than one at a time? You can remove index paths
// here, too. Just reload them below
[self.tableView beginUpdates];
[self.tableView reloadRowsAtIndexPaths:self.enlargedIndexPaths] withRowAnimation:UITableViewRowAnimationTop];
[self.tableView endUpdates];
好吧,我們的想法是根據您為單元格設置的值更改單元格高度。 你可以有一個NSArray,你可以在其中為所有單元格標記一個值:isExpanded(true或false)。
回顧一下,創建一個NSMutableArray來存儲單元格狀態(是否展開):
NSMutableArray *cellState;
初始化數組並用所有UITableView項Array填充零。 展開單元格時,將cellState objectAtIndex值從0設置為1(將其標記為展開)。
然后重新加載該單元格:
[self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:[NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section]] withRowAnimation:UITableViewRowAnimationFade];
並修改- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;
函數在單元格擴展時返回更大的值...
而已!
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