iOS动态高度评论框

核心代码：

import "HCTextView.h"

import "UIView+CLKAddition.h"

#import "Masonry.h"

#define ScreenWidth  [UIScreen mainScreen].bounds.size.width

#define WIDTH  ScreenWidth/375

@implementation HCTextView

{

float _currentLineNum;

}

- (instancetype)initWithFrame:(CGRect)frame

{

self = [super initWithFrame:frame];

if (self) {

self.backgroundColor = [UIColor colorWithHexString:@"#E6E6E6"];

_currentLineNum=1;//默认文本框显示一行文字

[self addSubviews];

}

return self;

}

- (void)addSubviews{

self.commentField = [[UITextView alloc]init];

self.commentField.backgroundColor = [UIColor colorWithHexString:@"#f8f8f8"];

self.commentField.font = [UIFont systemFontOfSize:12];

self.commentField.text = @"｜说说你的看法～";

self.commentField.textColor = [UIColor colorWithHexString:@"#a0a0a0"];

self.commentField.layer.cornerRadius = 4;

self.commentField.layer.masksToBounds = YES;

[self addSubview:self.commentField];

self.commentField.contentInset = UIEdgeInsetsMake(-66,0,0,0);

self.commentField.delegate = self;

self.publishBtn = [[UIButton alloc]init];

[self.publishBtn setTitle:@"发布" forState:UIControlStateNormal];

[self.publishBtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];

[self.publishBtn setBackgroundColor:[UIColor colorWithHexString:@"23aBec"]];

self.publishBtn.layer.cornerRadius = 2;

self.publishBtn.layer.masksToBounds = YES;

[self addSubview:self.publishBtn];

}

-(void)layoutSubviews{

[super layoutSubviews];

[self.publishBtn mas_makeConstraints:^(MASConstraintMaker *make) {

make.size.mas_equalTo(CGSizeMake(80*WIDTH, 32));

make.right.equalTo(@-10);

make.bottom.equalTo(@-8);

}];

[self.commentField mas_makeConstraints:^(MASConstraintMaker *make) {

make.left.equalTo(@10);

make.right.equalTo(self.publishBtn.mas_left).offset(-10);

make.centerY.mas_equalTo(self);

make.height.greaterThanOrEqualTo(@26);

}];

}

#pragma mark - UITextViewDelegate

- (void)textViewDidBeginEditing:(UITextView *)textView {

if ([textView.text isEqualToString:@"｜说说你的看法～"]) {

textView.text = @"";

self.commentField.textColor = [UIColor colorWithHexString:@"#646464"];

self.commentField.contentInset = UIEdgeInsetsMake(2,0,-2,0);

}

}

- (void)textViewDidEndEditing:(UITextView *)textView {

if (textView.text.length<1) {

textView.text = @"｜说说你的看法～";

textView.textColor = [UIColor colorWithHexString:@"#a0a0a0"];

}

self.commentField.contentInset = UIEdgeInsetsMake(2,0,-2,0);

}

-(void)textViewDidChange:(UITextView *)textView{

float textViewWidth=textView.frame.size.width;//取得文本框高度

NSString *content=textView.text;

NSDictionary *dict=@{NSFontAttributeName:[UIFont systemFontOfSize:12.0]};

CGSize contentSize=[content sizeWithAttributes:dict];//计算文字长度

float numLine=ceilf(contentSize.width/textViewWidth); //计算当前文字长度对应的行数

if (numLine>10) {

numLine=10;

}

CGFloat heightText = 14;

if (numLine != 0) {

if (numLine>_currentLineNum) {

self.frame = CGRectMake(self.frame.origin.x,self.frame.origin.y-heightText*(numLine-_currentLineNum), ScreenWidth, self.frame.size.height+heightText*(numLine-_currentLineNum));

[self.commentField mas_updateConstraints:^(MASConstraintMaker *make) {

make.height.equalTo(@(self.commentField.frame.size.height+heightText*(numLine-_currentLineNum)));

}];

_currentLineNum=numLine;

}else if(numLine<_currentLineNum){

self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y-heightText*(numLine-_currentLineNum), ScreenWidth, self.frame.size.height+heightText*(numLine-_currentLineNum));

[self.commentField mas_updateConstraints:^(MASConstraintMaker *make) {

make.height.equalTo(@(self.commentField.frame.size.height+heightText*(numLine-_currentLineNum)));

}];

_currentLineNum=numLine;

}

}

}

@end

动态高度评论框.png