iOSLabel自适应高度实现
2021-09-10 本文已影响0人
数字d
需求:根据服务端返回的字符串数据来展示Label
1.label行数根据字符串长度来增加,默认展示行数小于等于三行
2.label需要展示在一个灰色背景中,label的frame发生变化,灰色背景的frame也发生变化
3.label如果超出三行,第三行尾部省略...,并在灰色背景底部添加一个"显示全部的"按钮
4.点击显示全部,Label行数根据实际展示,不进行折叠并展示另外一个按钮"收起"
5.点击收起,Label重新折叠成三行
效果
1
2
3
步骤:
使用textField模拟服务端返回的字符串,点击蓝色Label模拟开始展示Label和灰色背景view,调试之后第二次输入需要重新运行
核心代码:
1.动态计算label的高度
-(CGFloat)caculateNeedHeightWithString:(NSString *)inputString {
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, Screen_Width - 30 - 22, 0)];
label.text = inputString;
label.font = [UIFont systemFontOfSize:11];
label.numberOfLines = 0;
[label sizeToFit];
CGFloat height = label.frame.size.height;
return height;
}
- 根据高度和打印结果估算行数,影响行数的因素是字体大小,Label的初始宽度,textField中的输入监听和一些常规信息展示,如果行数超过三行标记extend为YES
[[self.textField rac_textSignal] subscribeNext:^(NSString * _Nullable x) {
CGFloat height = [self caculateNeedHeightWithString:x];
NSLog(@"%f",height);
if (height < 15) {
NSLog(@"1行");
weakSelf.minHeight = height + 2;
weakSelf.maxHeight = height + 2;
weakSelf.seeTotalLab.hidden = YES;
weakSelf.seezoomLab.hidden = YES;
weakSelf.lineNeed = 1;
}else if (height < 30){
NSLog(@"2行");
weakSelf.minHeight = height + 2;
weakSelf.maxHeight = height + 2;
weakSelf.seeTotalLab.hidden = YES;
weakSelf.seezoomLab.hidden = YES;
weakSelf.lineNeed = 2;
}else if (height < 45){
NSLog(@"3行");
weakSelf.minHeight = height + 2;
weakSelf.maxHeight = height + 2;
weakSelf.seeTotalLab.hidden = YES;
weakSelf.seezoomLab.hidden = YES;
weakSelf.lineNeed = 3;
}else{
weakSelf.extend = YES;
weakSelf.lineNeed = height / 13;
NSLog(@"4行或者4行多 %ld",(long)weakSelf.lineNeed);
weakSelf.minHeight = 40;
weakSelf.maxHeight = height + 2;
}
weakSelf.lineLab.text = [NSString stringWithFormat:@"总共 %ld行 现在占用实际高度是 %f + %ld",(long)weakSelf.lineNeed,height, (weakSelf.lineNeed - 1) * 5];
}];
3.蓝色文字的label的实现和点击事件的处理,将grayBgview展示在view上
-(UILabel *)clickLab {
if (_clickLab == nil) {
_clickLab = [[UILabel alloc] initWithFrame:CGRectMake(0, 160, Screen_Width, 40)];
_clickLab.text = @"点击我之后,grayview和infolabel展示在self.view上";
_clickLab.textAlignment = NSTextAlignmentCenter;
_clickLab.font = [UIFont boldSystemFontOfSize:15];
_clickLab.adjustsFontSizeToFitWidth = YES;
_clickLab.textColor = [UIColor blueColor];
_clickLab.userInteractionEnabled = YES;
WS(weakSelf);
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] init];
[[tap rac_gestureSignal] subscribeNext:^(__kindof UIGestureRecognizer * _Nullable x) {
[weakSelf.view addSubview:self.bgGrayView];
[weakSelf.textField resignFirstResponder];
}];
[_clickLab addGestureRecognizer:tap];
}
return _clickLab;
}
4.查看全部的按钮(UILabel)事件监听
-(UILabel *)seeTotalLab {
if (_seeTotalLab == nil) {
_seeTotalLab = [[UILabel alloc] init];
_seeTotalLab.text = @"查看全部";
_seeTotalLab.textAlignment = NSTextAlignmentRight;
_seeTotalLab.font = [UIFont systemFontOfSize:11];
_seeTotalLab.textColor = [UIColor blueColor];
_seeTotalLab.userInteractionEnabled = YES;
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] init];
WS(weakSelf);
[[tap rac_gestureSignal] subscribeNext:^(__kindof UIGestureRecognizer * _Nullable x) {
weakSelf.bgGrayView.frame = CGRectMake(weakSelf.bgGrayView.frame.origin.x, weakSelf.bgGrayView.frame.origin.y, weakSelf.bgGrayView.frame.size.width, _maxHeight + 20 + 18 + (self.lineNeed - 1) * 5);
weakSelf.infoLab.numberOfLines = 0;
weakSelf.seeTotalLab.hidden = YES;
weakSelf.seezoomLab.hidden = NO;
}];
[_seeTotalLab addGestureRecognizer:tap];
}
return _seeTotalLab;
}
5.收起的按钮(UILabel)实现和事件监听
-(UILabel *)seezoomLab {
if (_seezoomLab == nil) {
_seezoomLab = [[UILabel alloc] init];
_seezoomLab.text = @"收起";
_seezoomLab.textAlignment = NSTextAlignmentRight;
_seezoomLab.font = [UIFont systemFontOfSize:11];
_seezoomLab.textColor = [UIColor blueColor];
_seezoomLab.userInteractionEnabled = YES;
WS(weakSelf);
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] init];
[[tap rac_gestureSignal] subscribeNext:^(__kindof UIGestureRecognizer * _Nullable x) {
weakSelf.bgGrayView.frame = CGRectMake(weakSelf.bgGrayView.frame.origin.x, weakSelf.bgGrayView.frame.origin.y, weakSelf.bgGrayView.frame.size.width, _minHeight + 20 + 18 + (3 - 1) * 5);
weakSelf.infoLab.numberOfLines = 3;
weakSelf.seeTotalLab.hidden = NO;
weakSelf.seezoomLab.hidden = YES;
}];
[_seezoomLab addGestureRecognizer:tap];
}
return _seezoomLab;
}
6.
-(UILabel *)infoLab {
if (_infoLab == nil) {
_infoLab = [[UILabel alloc] init];
// _infoLab.text = self.textField.text;
_infoLab.numberOfLines = 3;
// _infoLab.backgroundColor = [UIColor blueColor];
_infoLab.textAlignment = NSTextAlignmentLeft;
_infoLab.font = [UIFont systemFontOfSize:11];
_infoLab.textColor = [UIColor blackColor];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
// 行间距设置为5
[paragraphStyle setLineSpacing:5];
[paragraphStyle setLineBreakMode:NSLineBreakByTruncatingTail];
NSString *testString = self.textField.text;
NSMutableAttributedString *setString = [[NSMutableAttributedString alloc] initWithString:testString];
[setString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [testString length])];
// 设置Label要显示的text
[_infoLab setAttributedText:setString];
_infoLab.backgroundColor = [UIColor yellowColor];
}
return _infoLab;
}
因为有时候要用到这种计算高度且加限制最小行数的折叠需求,干脆整理出来单独实现,viewcontroller中所有的代码
//
// ViewController.m
// raceme
//
// Created by mac on 2021/9/3.
//
#import "ViewController.h"
@interface ViewController ()
@property(nonatomic,strong)UITextField * textField;
@property(nonatomic,strong)UILabel * clickLab;
@property(nonatomic,strong)UIView * bgGrayView;
@property(nonatomic,strong)UILabel * infoLab;
@property(nonatomic,strong)UILabel * seeTotalLab;
@property(nonatomic,strong)UILabel * seezoomLab;
@property(nonatomic,strong)UILabel * lineLab;
@property(nonatomic,assign)CGFloat minHeight;
@property(nonatomic,assign)CGFloat maxHeight;
@property(nonatomic,assign)NSInteger lineNeed;
@property(nonatomic,assign)BOOL extend;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self.view addSubview:self.textField];
[self.view addSubview:self.clickLab];
[self.view addSubview:self.lineLab];
_extend = NO;
WS(weakSelf);
[[self.textField rac_textSignal] subscribeNext:^(NSString * _Nullable x) {
CGFloat height = [self caculateNeedHeightWithString:x];
NSLog(@"%f",height);
if (height < 15) {
NSLog(@"1行");
weakSelf.minHeight = height + 2;
weakSelf.maxHeight = height + 2;
weakSelf.seeTotalLab.hidden = YES;
weakSelf.seezoomLab.hidden = YES;
weakSelf.lineNeed = 1;
}else if (height < 30){
NSLog(@"2行");
weakSelf.minHeight = height + 2;
weakSelf.maxHeight = height + 2;
weakSelf.seeTotalLab.hidden = YES;
weakSelf.seezoomLab.hidden = YES;
weakSelf.lineNeed = 2;
}else if (height < 45){
NSLog(@"3行");
weakSelf.minHeight = height + 2;
weakSelf.maxHeight = height + 2;
weakSelf.seeTotalLab.hidden = YES;
weakSelf.seezoomLab.hidden = YES;
weakSelf.lineNeed = 3;
}else{
weakSelf.extend = YES;
weakSelf.lineNeed = height / 13;
NSLog(@"4行或者4行多 %ld",(long)weakSelf.lineNeed);
weakSelf.minHeight = 40;
weakSelf.maxHeight = height + 2;
}
weakSelf.lineLab.text = [NSString stringWithFormat:@"总共 %ld行 现在占用实际高度是 %f + %ld",(long)weakSelf.lineNeed,height, (weakSelf.lineNeed - 1) * 5];
}];
}
-(UITextField * )textField {
if (_textField == nil) {
_textField = [[UITextField alloc] initWithFrame:CGRectMake(20, 88, Screen_Width - 20, 45)];
_textField.placeholder = @"输入文字内容吧";
_textField.textAlignment = NSTextAlignmentCenter;
_textField.font = [UIFont systemFontOfSize:11];
_textField.backgroundColor = [UIColor groupTableViewBackgroundColor];
_textField.textColor = [UIColor blackColor];
}
return _textField;
}
-(UILabel *)clickLab {
if (_clickLab == nil) {
_clickLab = [[UILabel alloc] initWithFrame:CGRectMake(0, 160, Screen_Width, 40)];
_clickLab.text = @"点击我之后,grayview和infolabel展示在self.view上";
_clickLab.textAlignment = NSTextAlignmentCenter;
_clickLab.font = [UIFont boldSystemFontOfSize:15];
_clickLab.adjustsFontSizeToFitWidth = YES;
_clickLab.textColor = [UIColor blueColor];
_clickLab.userInteractionEnabled = YES;
WS(weakSelf);
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] init];
[[tap rac_gestureSignal] subscribeNext:^(__kindof UIGestureRecognizer * _Nullable x) {
[weakSelf.view addSubview:self.bgGrayView];
[weakSelf.textField resignFirstResponder];
}];
[_clickLab addGestureRecognizer:tap];
}
return _clickLab;
}
-(CGFloat)caculateNeedHeightWithString:(NSString *)inputString {
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, Screen_Width - 30 - 22, 0)];
label.text = inputString;
label.font = [UIFont systemFontOfSize:11];
label.numberOfLines = 0;
[label sizeToFit];
CGFloat height = label.frame.size.height;
return height;
}
-(UIView *)bgGrayView {
if (_bgGrayView == nil) {
CGFloat totalBgHeight;
if (_extend) {
totalBgHeight = _minHeight + 20 + (3 - 1) * 5;
totalBgHeight += 22;
}else {
totalBgHeight = _minHeight + 20 + (self.lineNeed - 1) * 5;
}
_bgGrayView = [[UIView alloc] initWithFrame:CGRectMake(15, 200, Screen_Width - 30, totalBgHeight)];
_bgGrayView.backgroundColor = [UIColor groupTableViewBackgroundColor];
[_bgGrayView addSubview:self.infoLab];
[self.infoLab mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(_bgGrayView.mas_left).offset(11);
make.right.equalTo(_bgGrayView.mas_right).offset(-11);
make.height.greaterThanOrEqualTo(@10);
make.top.equalTo(_bgGrayView.mas_top).offset(10);
}];
[_bgGrayView addSubview:self.seeTotalLab];
[_bgGrayView addSubview:self.seezoomLab];
[self.seeTotalLab mas_makeConstraints:^(MASConstraintMaker *make) {
make.right.equalTo(_bgGrayView.mas_right).offset(-10.5);
make.width.equalTo(@100);
make.height.equalTo(@22);
make.bottom.equalTo(_bgGrayView.mas_bottom).offset(-10);
}];
self.seeTotalLab.hidden = !_extend;
[self.seezoomLab mas_makeConstraints:^(MASConstraintMaker *make) {
make.right.equalTo(_bgGrayView.mas_right).offset(-10.5);
make.width.equalTo(@70);
make.height.equalTo(@22);
make.bottom.equalTo(_bgGrayView.mas_bottom).offset(-10);
}];
self.seezoomLab.hidden = YES;
}
return _bgGrayView;
}
-(UILabel *)infoLab {
if (_infoLab == nil) {
_infoLab = [[UILabel alloc] init];
// _infoLab.text = self.textField.text;
_infoLab.numberOfLines = 3;
// _infoLab.backgroundColor = [UIColor blueColor];
_infoLab.textAlignment = NSTextAlignmentLeft;
_infoLab.font = [UIFont systemFontOfSize:11];
_infoLab.textColor = [UIColor blackColor];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
// 行间距设置为5
[paragraphStyle setLineSpacing:5];
[paragraphStyle setLineBreakMode:NSLineBreakByTruncatingTail];
NSString *testString = self.textField.text;
NSMutableAttributedString *setString = [[NSMutableAttributedString alloc] initWithString:testString];
[setString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [testString length])];
// 设置Label要显示的text
[_infoLab setAttributedText:setString];
_infoLab.backgroundColor = [UIColor yellowColor];
}
return _infoLab;
}
-(UILabel *)seeTotalLab {
if (_seeTotalLab == nil) {
_seeTotalLab = [[UILabel alloc] init];
_seeTotalLab.text = @"查看全部";
_seeTotalLab.textAlignment = NSTextAlignmentRight;
_seeTotalLab.font = [UIFont systemFontOfSize:11];
_seeTotalLab.textColor = [UIColor blueColor];
_seeTotalLab.userInteractionEnabled = YES;
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] init];
WS(weakSelf);
[[tap rac_gestureSignal] subscribeNext:^(__kindof UIGestureRecognizer * _Nullable x) {
weakSelf.bgGrayView.frame = CGRectMake(weakSelf.bgGrayView.frame.origin.x, weakSelf.bgGrayView.frame.origin.y, weakSelf.bgGrayView.frame.size.width, _maxHeight + 20 + 18 + (self.lineNeed - 1) * 5);
weakSelf.infoLab.numberOfLines = 0;
weakSelf.seeTotalLab.hidden = YES;
weakSelf.seezoomLab.hidden = NO;
}];
[_seeTotalLab addGestureRecognizer:tap];
}
return _seeTotalLab;
}
-(UILabel *)seezoomLab {
if (_seezoomLab == nil) {
_seezoomLab = [[UILabel alloc] init];
_seezoomLab.text = @"收起";
_seezoomLab.textAlignment = NSTextAlignmentRight;
_seezoomLab.font = [UIFont systemFontOfSize:11];
_seezoomLab.textColor = [UIColor blueColor];
_seezoomLab.userInteractionEnabled = YES;
WS(weakSelf);
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] init];
[[tap rac_gestureSignal] subscribeNext:^(__kindof UIGestureRecognizer * _Nullable x) {
weakSelf.bgGrayView.frame = CGRectMake(weakSelf.bgGrayView.frame.origin.x, weakSelf.bgGrayView.frame.origin.y, weakSelf.bgGrayView.frame.size.width, _minHeight + 20 + 18 + (3 - 1) * 5);
weakSelf.infoLab.numberOfLines = 3;
weakSelf.seeTotalLab.hidden = NO;
weakSelf.seezoomLab.hidden = YES;
}];
[_seezoomLab addGestureRecognizer:tap];
}
return _seezoomLab;
}
-(UILabel *)lineLab {
if (_lineLab == nil) {
_lineLab = [[UILabel alloc] initWithFrame:CGRectMake(0, 64, Screen_Width, 22)];
_lineLab.textAlignment = NSTextAlignmentLeft;
_lineLab.font = [UIFont systemFontOfSize:12];
_lineLab.textColor = [UIColor blackColor];
}
return _lineLab;
}
@end
