###因为项目的需要，在单个tableViewCell中需要对过多的文字进行展开收起的动作
####1.首先创建一个Model类来返回行高
/*
*str:传入字符串
*isShow:是否全部显示
*width:label的宽度
*font:label字号
*defaultHeight:默认label的高度
*fixedHeight:除label以外的固定高度
*返回cell的高度
*/
+ (CGFloat)cellHeightWith:(NSString *)str andIsShow:(BOOL)isShow andLableWidth:(CGFloat)width andFont:(CGFloat)font andDefaultHeight:(CGFloat)defaultHeight andFixedHeight:(CGFloat)fixedHeight{
CGSize size = [str boundingRectWithSize:CGSizeMake(width, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:font]} context:nil].size;
if (size.height > defaultHeight) {
if (isShow) {
return size.height + fixedHeight;
}
else{
return defaultHeight + fixedHeight;
}
}
else{
return defaultHeight + fixedHeight;
}
}
####2.在Controller中写一个可变字典保存展开状态
//保存cell的展开状态
@property(nonatomic,strong)NSMutableDictionary *showDictionary;
####3.在tableView返回行高的代理方法中根据展开状态字典返回对应行高
#pragma mark UITableViewDelegate
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
return [HeightModel cellHeightWith:self.dataArray[indexPath.row] andIsShow:[[self.showDictionary objectForKey:[NSString stringWithFormat:@"%ld", indexPath.row]] boolValue] andLableWidth:WIDTH - 30 andFont:12 andDefaultHeight:15 andFixedHeight:39];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
TextTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"DetailTextTableViewCell"];
if (!cell) {
cell = [[TextTableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:@"DetailTextTableViewCell"];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
cell.delegate = self;
//cell展开按钮点击触发的block
cell.moreBlock = ^(NSDictionary *dic,NSIndexPath *indexPath){
[self.showDictionary setObject:[dic objectForKey:@"isShow"] forKey:[NSString stringWithFormat:@"%@",[dic objectForKey:@"row"]]];
[self.rootTableView reloadData];
};
[cell setCellContent:[self.dataArray objectAtIndex:indexPath.row] andIsShow:[[self.showDictionary objectForKey:[NSString stringWithFormat:@"%ld", indexPath.row]] boolValue] andCellIndexPath:indexPath];
return cell;
}
####4.设置属性，点击展开按钮block
//点击按钮的block
@property(nonatomic,copy)void (^moreBlock)(NSDictionary *dic,NSIndexPath *indexPath);
####5.设置AutoLayout
//label的autolayout，使用的国内大神的库SDAutoLayout，也可以使用masonry
-(void)layout{
[self.contentView sd_addSubviews:@[_detailLabel]];
_detailLabel.sd_layout
.topSpaceToView(self.contentView,32)
.bottomSpaceToView(self.contentView,7)
.leftSpaceToView(self.contentView,20)
.rightSpaceToView(self.contentView,10)
.widthIs(WIDTH - 30);
[self.contentView updateLayout];
}
####6.cell的赋值方法
//cell的赋值方法，传入字符串，是否全部显示，tanleView的位置信息
- (void)setCellContent:(NSString *)str andIsShow:(BOOL)isShow andCellIndexPath:(NSIndexPath *)indexPath{
_detailLabel.text = str;
_theIndexPath = indexPath;
//根据需求添加无数据时候的显示逻辑
if ([str isEqualToString:@""]) {
_detailLabel.text = @"暂无文字";
}
CGSize size = [str boundingRectWithSize:CGSizeMake(WIDTH-30, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:12]} context:nil].size;
//最小的label高度是15
if (size.height > 15) {
_moreButton.hidden = NO;
_actionButton.hidden = NO;
if (isShow) {
_detailLabel.numberOfLines = 0;
}
else{
_detailLabel.numberOfLines = 1;
}
_moreButton.selected = isShow;
}else{
_detailLabel.numberOfLines = 1;
_moreButton.hidden = YES;
_actionButton.hidden = YES;
}
[self updateLayout];
}
####7.按钮的点击方法
//按钮点击方法
-(void)moreButtonClick{
_moreButton.selected = !_moreButton.selected;
NSMutableDictionary *dic = [NSMutableDictionary dictionary];
[dic setObject:[NSNumber numberWithInteger:_theIndexPath.row] forKey:@"row"];
[dic setObject:[NSNumber numberWithBool:_moreButton.selected] forKey:@"isShow"];
self.moreBlock(dic,_theIndexPath);
}
代码仅供参考，希望可以帮到你，如果你有更好的方法还希望能互相学习互相进步！