iOS UITextField自动换行

在网上查了一下，UITextField没有自动换行的代码，所以呢，我就用了一种相对 liu mang的方式实现了一下，但是也有不足，光标无法移动，（其实根本就没有光标。。。(⊙﹏⊙)b）
如果大家有什么好的方法希望大家多多指教。。。
废话不多说，代码如下：

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主要代码

#import <UIKit/UIKit.h>@interface CustomTextField : UITextField<UITextFieldDelegate>/** *  自定义初始化方法 * *  @param frame       frame *  @param placeholder 提示语 *  @param clear       是否显示清空按钮 YES为显示 *  @param view        是否设置leftView不设置传nil *  @param font        设置字号 * *  @return  */-(id)initWithFrame:(CGRect)frame placeholder:(NSString *)placeholder clear:(BOOL)clear leftView:(id)view fontSize:(CGFloat)font;@end

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主要实现代码

#import "CustomTextField.h"@implementation CustomTextField{    //坐标    CGRect   _frame;    //用label显示内容    UILabel  *_label;    //是否显示清空按钮    BOOL     _clear;    //设置leftView    UIView   *_leftView;    //设置字号    CGFloat  _fontSize;}/** *  自定义初始化方法 * *  @param frame       frame *  @param placeholder 提示语 *  @param clear       是否显示清空按钮 YES为显示 *  @param view        是否设置leftView不设置传nil *  @param font        设置字号 * *  @return */-(id)initWithFrame:(CGRect)frame placeholder:(NSString *)placeholder clear:(BOOL)clear leftView:(id)view fontSize:(CGFloat)font{    self = [super initWithFrame:frame];    if (self) {        _frame = frame;        _clear = clear;        _leftView = (UIView *)view;        _fontSize = font;        self.placeholder = placeholder;        self.textColor = [UIColor clearColor];        self.font = [UIFont systemFontOfSize:_fontSize];        self.delegate = self;        if (clear) {            self.clearButtonMode = UITextFieldViewModeAlways;        }        if (view) {            self.leftView = view;            self.leftViewMode = UITextFieldViewModeAlways;        }        [self createLabel];        [self addTarget:self action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];    }    return self;}/** *  监听textField内容的改变 * *  @param sender */- (void) textFieldDidChange:(id) sender {    UITextField *textField = (UITextField *)sender;    CGSize size = [self labelText:[NSString stringWithFormat:@"%@|",textField.text] fondSize:_fontSize width:_label.frame.size.width];    _label.frame = CGRectMake(_label.frame.origin.x, _label.frame.origin.y, _label.frame.size.width, size.height < _frame.size.height ? _frame.size.height : size.height);    self.frame = CGRectMake(_frame.origin.x, _frame.origin.y, _frame.size.width, size.height < _frame.size.height ? _frame.size.height : size.height);    if (textField.text.length == 0) {        _label.text = @"";        self.tintColor=[UIColor blueColor];    }else{        //添加一个假的光标        self.tintColor=[UIColor clearColor];        NSString *text = [NSString stringWithFormat:@"%@|",textField.text];        NSMutableAttributedString *attString = [[NSMutableAttributedString alloc]initWithString:text];        [attString addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(text.length - 1, 1)];        _label.attributedText = attString;    }}/** *  创建label */-(void)createLabel{    _label = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, _frame.size.width, _frame.size.height)];    if (_leftView) {        _label.frame = CGRectMake(_leftView.frame.size.width, _label.frame.origin.y, _label.frame.size.width-_leftView.frame.size.width, _label.frame.size.height);    }    if (_clear) {        _label.frame = CGRectMake(_label.frame.origin.x, _label.frame.origin.y, _label.frame.size.width-20, _label.frame.size.height);    }    _label.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0];    _label.font = [UIFont systemFontOfSize:_fontSize];    _label.numberOfLines = 0;    [self addSubview:_label];}#pragma mark - UITextFieldDelegate//点击return回收键盘-(BOOL)textFieldShouldReturn:(UITextField *)textField{    [textField resignFirstResponder];    return YES;}//开始编辑- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{    NSLog(@"将要编辑");    return YES;}//开始编辑- (void)textFieldDidBeginEditing:(UITextField *)textField{    NSLog(@"开始编辑");}//将要编辑完成- (BOOL)textFieldShouldEndEditing:(UITextField *)textField{    NSLog(@"将要编辑完成");    return YES;}//编辑完成- (void)textFieldDidEndEditing:(UITextField *)textField{    NSLog(@"编辑完成");}//点击键盘调用- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{    NSLog(@"点击键盘调用");    return YES;}//点击清空按钮- (BOOL)textFieldShouldClear:(UITextField *)textField{    NSLog(@"清空");    _label.text = @"";    return YES;}/** *  计算字符串长度，UILabel自适应高度 * *  @param text  需要计算的字符串 *  @param size  字号大小 *  @param width 最大宽度 * *  @return 返回大小 */-(CGSize)labelText:(NSString *)text fondSize:(float)size width:(CGFloat)width{    NSDictionary *send = @{NSFontAttributeName: [UIFont systemFontOfSize:size]};    CGSize textSize = [text boundingRectWithSize:CGSizeMake(width, 0)                                         options:NSStringDrawingTruncatesLastVisibleLine |                       NSStringDrawingUsesLineFragmentOrigin |                       NSStringDrawingUsesFontLeading                                      attributes:send context:nil].size;    return textSize;}/*// Only override drawRect: if you perform custom drawing.// An empty implementation adversely affects performance during animation.- (void)drawRect:(CGRect)rect {    // Drawing code}*/@end

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使用起来和UITextField一样

    //设置leftView    UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 30, 30)];    imageView.image = [UIImage imageNamed:@"image.jpg"];    imageView.clipsToBounds = YES;    imageView.layer.cornerRadius = imageView.frame.size.height/2;    //初始化    CustomTextField *textField = [[CustomTextField alloc]initWithFrame:CGRectMake(10, 40, 300, 30) placeholder:@"自动换行textField" clear:YES leftView:imageView fontSize:20.0];    textField.layer.borderWidth = 1.0;    textField.layer.borderColor = [UIColor purpleColor].CGColor;    textField.layer.cornerRadius = textField.frame.size.height/2;    [self.view addSubview:textField];

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其实主要的实现就是通过UILabel的自动换行实现的，希望对大家有所帮助。。。下面是效果图