自定义UITextView

这里我们创建一个继承自UIView，内嵌UITextView的类

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• HJTextView.h

////  HJTextView.h//  HJTextView////  Created by 黄健 on 16/5/27.//  Copyright © 2016年 黄健. All rights reserved.//#import <UIKit/UIKit.h>@interface HJTextView : UIView@property (nonatomic, assign) int maxLength;// 最大字数@property (nonatomic, retain) UIFont *font;// 字体大小，默认14@property (nonatomic, retain) UIColor *textColor;// 字体颜色@property (nonatomic, retain) UIColor *placeholderColor;// 提示文字颜色@property (nonatomic) UIEdgeInsets contentEdgeInsets;// 内间距@property (nonatomic, copy) NSString *text;// 文本域内容@property (nonatomic, copy) NSString *placeholder;// 提示文字@end

• HJTextView.m

////  HJTextView.m//  HJTextView////  Created by 黄健 on 16/5/27.//  Copyright © 2016年 黄健. All rights reserved.//#import "HJTextView.h"// 视图的宽高#define kWidth  self.bounds.size.width#define kHeight self.bounds.size.height// 默认内间距#define kPadding 2// 文本域宽度#define kTextViewWidth _textView.bounds.size.width@interface HJTextView() <UITextViewDelegate>{    @private        UITextView *_textView;// 内嵌文本域        UILabel *_tipLabel;// 提示文字标签        UILabel *_numLabel;// 字数限制标签}@end@implementation HJTextView- (instancetype)initWithFrame:(CGRect)frame{    if (self == [super initWithFrame:frame])    {        [self initView];    }    return self;}- (void)initView{    self.backgroundColor = [UIColor whiteColor];    _textView                 = [[UITextView alloc] init];    _textView.font            = [UIFont systemFontOfSize:14];    _textView.frame           = CGRectMake(kPadding, kPadding, kWidth - 2 * kPadding, kHeight - 2 * kPadding);    _textView.delegate        = self;    _textView.backgroundColor = [UIColor clearColor];    [self addSubview:_textView];}- (void)setFrame:(CGRect)frame{    [super setFrame:frame];    [self initView];    [self setNeedsDisplay];}- (void)setMaxLength:(int)maxLength{    _maxLength     = maxLength;    _numLabel      = [[UILabel alloc] init];    _numLabel.font = [UIFont systemFontOfSize:13];    CGFloat w = 100;    CGFloat h = _numLabel.font.lineHeight + 2;    CGFloat x = kWidth - w - 7;    CGFloat y = kHeight - h - 5;    _numLabel.frame         = CGRectMake(x, y, w, h);    _numLabel.textAlignment = NSTextAlignmentRight;    _numLabel.textColor     = [UIColor colorWithWhite:0.8 alpha:1.0];    [self addSubview:_numLabel];    _numLabel.text = [NSString stringWithFormat:@"0/%d", maxLength];}- (void)setTextColor:(UIColor *)textColor{    _textColor = textColor;    _textView.textColor = textColor;}- (void)setPlaceholderColor:(UIColor *)placeholderColor{    _placeholderColor = placeholderColor;    _tipLabel.textColor = _placeholderColor;    _numLabel.textColor = _placeholderColor;}- (void)setPlaceholder:(NSString *)placeholder{    _placeholder = placeholder;    _tipLabel               = [[UILabel alloc] init];    _tipLabel.font          = _textView.font;    _tipLabel.text          = _placeholder;    _tipLabel.textColor     = _placeholderColor ? _placeholderColor : [UIColor colorWithWhite:0.8 alpha:1.0];    _tipLabel.numberOfLines = 0;    [_textView addSubview:_tipLabel];    [_textView sendSubviewToBack:_tipLabel];    CGSize contentSize = [self contentSize:_placeholder withFont:_tipLabel.font andMaxWith:kTextViewWidth - 5];    _tipLabel.frame = CGRectMake(5, 8, contentSize.width, contentSize.height);}- (CGSize)contentSize:(NSString *)content withFont:(UIFont *)font andMaxWith:(CGFloat)maxWidth{    return [content boundingRectWithSize:CGSizeMake(maxWidth, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:font} context:nil].size;}- (void)setText:(NSString *)text{    _textView.text   = text;    _tipLabel.hidden = text.length > 0;}- (NSString *)text{    return _textView.text;}- (void)setFont:(UIFont *)font{    _textView.font = font;    _tipLabel.font = font;}- (void)setContentEdgeInsets:(UIEdgeInsets)contentEdgeInsets{    CGFloat x = contentEdgeInsets.left;    CGFloat y = contentEdgeInsets.top;    CGFloat w = kWidth - x - contentEdgeInsets.right;    CGFloat h = kHeight - y - contentEdgeInsets.bottom;    _textView.frame = CGRectMake(x, y, w, h);}- (void)textViewDidChange:(UITextView *)textView{    _tipLabel.hidden = textView.text.length > 0;    _numLabel.text   = [NSString stringWithFormat:@"%ld/%d", textView.text.length, _maxLength];}- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{    NSInteger length = textView.text.length - range.length + text.length;    return length <= _maxLength;}@end

• 测试

HJTextView *hjTextView = [[HJTextView alloc] initWithFrame:CGRectMake(20, 50, screenW - 45, 90)];[self.view addSubview:hjTextView];hjTextView.font = [UIFont systemFontOfSize:14];hjTextView.maxLength = 20000;hjTextView.contentEdgeInsets = UIEdgeInsetsMake(2, 5, 25, 5);hjTextView.placeholder = @"请输入内容";

• 运行