textView截取字符串-医生工作台1期

textfield截取字符串
ios7 会崩溃
解:
之前的写法是这样的
正确的写法:
 
先判断markedTextRange是否为nil,   markedTextRange这个属性是啥意思呢
表示文件中当前选中的文本的长度,参考下面一片文章,详细讲解了这个属性的意思:
在解决上述问题的时候你需要判断markedTextRange是不是为Nil，如果为Nil的话就说明你现在没有未选中的字符，可以计算文字长度。否则此时计算出来的字符长度可能不正确
如果选中的长度为nil,即没有选中的长度,那么就正常计算字符串长度,如果超长就截取字符串
如果选中的长度不为nil,就是有选中的,那不用截取字符串,让他正常输入,超出了,真正往textFild填充的时候,, 选中的字符串的长度为nil了,这样就会走if判断,切割字符串
 
 
还写了下面的方法:
 
这个方法的作用是判断,是否需要修改text in range ,是否需要修改某一段文字, 如果不实现这个代理方法,在中文输入法下面，文字长度超出后,点击键盘,还是会联想字符串
里面的判断表示,如果没有选中的文本, 文本的总长度如果超出了限制,就不让它修改 return no
如果没有选中的文本,文本长度没有超出限制,可以修改 return yes
如果有选中的文本,让他修改 return yes
完整代码：
//
//  HDFWorkTableAddCheckItemView.h
//  newDoctor
//
//  Created by songximing on 16/8/20.
//  Copyright © 2016年 haodf.com. All rights reserved.
//

#import <UIKit/UIKit.h>

/**
 *  @author songximing, 16-08-20 16:08:31 22:12 -2
 *
 *  请输入检查项目View
 */
@interface HDFBenchAddCheckItemView : UIView
- (void)show;
@property (nonatomic, copy) HDFStringBlock saveStringBlock; //<!确定按钮保存的字符串

/**
 *  @author songximing, 16-08-20 21:08:01
 *
 *  请输入检查项目View 的初始化方法
 *
 *  @param frame       必须给frame(跟屏幕相等)
 *  @param content     带入的文案内容 第一次进入没有传 nil
 *  @param title       标题 "请输入检查项目" 或者 "请输入检验项目" 两个必须填写一个
 *  @param placeHolder 站位文字 必须传
 *
 *  @return self
 */
- (instancetype)initWithFrame:(CGRect)frame content:(NSString *)content title:(NSString *)title placeHolder:(NSString *)placeHolder;
@property (nonatomic, copy) NSString *cancelString; //!<清空
@end
//
//  HDFWorkTableAddCheckItemView.m
//  newDoctor
//
//  Created by songximing on 16/8/20.
//  Copyright © 2016年 haodf.com. All rights reserved.
//

#import "HDFBenchAddCheckItemView.h"
#import "NSString+HDFAdditions.h"

#define kDescriptionMAXLength 50 //最多50字
#define kTextViewStringWidth kScreenWidth - 50 - 30 // 50是白色View的左右间距  30是textView距离白色view的左右间距
#define kBenchBottomViewHeight 45.0f

@interface HDFBenchAddCheckItemView ()<UITextViewDelegate>
@property (nonatomic, strong) UITextView *textView;
@property (nonatomic, strong) UIView *whiteContainerView;
@property (nonatomic, strong) UIButton *cancelButton;
@property (nonatomic, strong) UIControl *bgCoverControl;
@property (nonatomic, copy) NSString *title;
@property (nonatomic, copy) NSString *content; //!<带入的文本内容
@property (nonatomic, copy) NSString *placeHolder; //!<textView站位文字
@end

@implementation HDFBenchAddCheckItemView

- (void)dealloc {
    LOG(@"请输入检查项目View释放了...");
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
}

- (instancetype)initWithFrame:(CGRect)frame content:(NSString *)content title:(NSString *)title placeHolder:(NSString *)placeHolder{
    if (self = [super initWithFrame:frame]) {
        self.title = title;
        self.content = content;
        self.placeHolder = placeHolder;
        [self configUI];
    }
    return self;
}

#pragma mark - UI
- (void)configUI {
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
    
    // 灰色遮罩
    UIControl *bgCoverControl = [UIControl hdf_viewWithSuperView:self constraints:^(MASConstraintMaker *make) {
        make.edges.mas_equalTo(0);
    } tap:^(UIGestureRecognizer *sender) {
//        [self dismiss];
    }];
    bgCoverControl.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0];
    self.bgCoverControl = bgCoverControl;
    
    // 白色背景
    UIView *whiteContainerView = [UIView hdf_viewWithSuperView:self constraints:^(MASConstraintMaker *make) {
        make.centerY.mas_equalTo(0);
        make.centerX.mas_equalTo(0);
        make.width.mas_equalTo(270);
    }];
    whiteContainerView.backgroundColor = kWColor;
    whiteContainerView.alpha = 0;
    whiteContainerView.layer.cornerRadius = 8;
    whiteContainerView.clipsToBounds = YES;
    self.whiteContainerView = whiteContainerView;
    
    // title
    UILabel *titleLabel = [UILabel hdf_labelWithText:@"请输入检查项目" font:kFontWithSize(17) superView:whiteContainerView constraints:^(MASConstraintMaker *make) {
        make.top.mas_equalTo(25);
        make.centerX.mas_equalTo(0);
    }];
    titleLabel.textAlignment = NSTextAlignmentCenter;
    if (self.title.length > 0) { // 设置标题
        titleLabel.text = self.title;
    }
    
    // 文本输入框
    self.textView = [UITextView hdf_textViewWithPlaceholder:@" " delegate:self superView:whiteContainerView constraints:^(MASConstraintMaker *make) {
        make.top.mas_equalTo(titleLabel.mas_bottom).offset(15);
        make.left.mas_equalTo(15);
        make.right.mas_equalTo(-15);
        make.height.mas_equalTo(kFontWithSize(19).lineHeight * 4);
    }];
    self.textView.layer.cornerRadius = 3;
    self.textView.clipsToBounds = YES;
    self.textView.layer.borderWidth = 0.5;
    self.textView.layer.borderColor = kColorWith16RGB(0xcccccc).CGColor;
    self.textView.hdf_placeholder = @"请输入检查项目";

    self.textView.backgroundColor = kColorWith16RGB(0xf8f8f8);
    self.textView.font = kFontWithSize(16);
    self.textView.hdf_placeholderFont = kFontWithSize(16);
    self.textView.hdf_placeholderLabel.numberOfLines = 0;
    self.textView.hdf_placeholderColor = [UIColor redColor];
    [self.textView.hdf_placeholderLabel mas_updateConstraints:^(MASConstraintMaker *make) {
        make.top.mas_equalTo(self.textView).offset(7.5);
        make.left.mas_equalTo(self.textView).offset(5);
        make.width.mas_equalTo(self.textView.mas_width).offset(-5); // 让站位文字换行
    }];
    
    if (self.content.length > 0) { // 带入的文本内容
        self.textView.text = self.content;
        self.textView.hdf_placeholder = self.placeHolder;
        self.textView.hdf_placeholderLabel.hidden = YES;
    }else { // 无内容,展示站位文字
        self.textView.hdf_placeholder = self.placeHolder;
        self.textView.hdf_placeholderLabel.hidden = NO;
    }
    
//    // textView高度自适应内容
//    CGSize textSize = CGSizeZero;
//    if (isIOS(7.0)) {
//        textSize = [self.textView sizeThatFits:CGSizeMake(kTextViewStringWidth, MAXFLOAT)];
//    }
//    else{
//        textSize = self.textView.contentSize;
//    }
//    if (kTextViewHeight < textSize.height) {
//        [self.textView mas_updateConstraints:^(MASConstraintMaker *make) {
//            make.height.mas_equalTo(textSize.height);
//        }];
//    }else {
//        [self.textView mas_updateConstraints:^(MASConstraintMaker *make) {
//            make.height.mas_equalTo(kTextViewHeight);
//        }];
//    }
    
    [self createBottomView];
}

- (void)createBottomView {
    UIView *bottomBgView = [[UIView alloc]init];
    [self.whiteContainerView addSubview:bottomBgView];
    [bottomBgView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.textView.mas_bottom).offset(15);
        make.left.right.equalTo(self.whiteContainerView);
        make.height.mas_equalTo(kBenchBottomViewHeight);
    }];
    
    // 水平分割线
    UIView *horizontalLineView = [[UIView alloc]init];
    [bottomBgView addSubview:horizontalLineView];
    horizontalLineView.backgroundColor = kG5Color;
    [horizontalLineView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(bottomBgView);
        make.left.right.equalTo(bottomBgView);
        make.height.mas_equalTo(kLineHeight);
    }];
    
    // 垂直分割线
    UIView *verticalLineView = [[UIView alloc]init];
    [bottomBgView addSubview:verticalLineView];
    verticalLineView.backgroundColor = kG5Color;
    [verticalLineView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.bottom.equalTo(bottomBgView);
        make.centerX.equalTo(bottomBgView);
        make.width.mas_equalTo(kLineHeight);
    }];
    
    kWeakObject(self)
    // 取消 按钮
    UIButton *cancelButton = [UIButton hdf_buttonWithTitle:@"取消" superView:bottomBgView constraints:^(MASConstraintMaker *make) {
        make.top.equalTo(horizontalLineView.mas_bottom);
        make.left.bottom.equalTo(bottomBgView);
        make.right.equalTo(verticalLineView.mas_left);
    } touchup:^(UIButton *sender) {
        [weakObject cancelButtonClick];
    }];
    [cancelButton setTitleColor:kNavColer forState:UIControlStateNormal];
    self.cancelButton = cancelButton;
    
    UIButton *confirmButton = [UIButton hdf_buttonWithTitle:@"确定" superView:bottomBgView constraints:^(MASConstraintMaker *make) {
        make.top.equalTo(horizontalLineView.mas_bottom);
        make.right.bottom.equalTo(bottomBgView);
        make.left.equalTo(verticalLineView.mas_right);
    } touchup:^(UIButton *sender) {
        [weakObject confirmButtonClick];
    }];
    [confirmButton setTitleColor:kNavColer forState:UIControlStateNormal];
    
    [self.whiteContainerView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.bottom.equalTo(bottomBgView);
    }];
}

#pragma mark - 点击事件
- (void)confirmButtonClick {
    // 去掉首尾的空格
    self.textView.text = [self.textView.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
    
//    if (self.textView.text.length < 1) {
//        [HDFHud showTip:@"请先输入检查项目"];
//        return;
//    }
    [self dismiss];
    if (self.saveStringBlock) {
        self.saveStringBlock(self.textView.text);
    }
}

- (void)cancelButtonClick {
//    self.textView.text = nil; // 点击取消,清空输入的文字
    [self dismiss];
//    if (self.saveStringBlock) {
//        self.saveStringBlock(self.textView.text);
//    }
}

#pragma UITextViewDelegate
-(void)textViewDidChange:(UITextView *)textView {
    if (self.textView.text.length == 0) {
        self.textView.hdf_placeholderLabel.hidden = NO;
    }else {
        self.textView.hdf_placeholderLabel.hidden = YES;
    }
    // 限制50个字数
    if (textView.markedTextRange == nil) {
        if (self.textView.text.length > kDescriptionMAXLength) {
            //        [HDFHud showTip:@"简介最多输入50个字"];
            self.textView.text = [self.textView.text substringToIndex: kDescriptionMAXLength]; // MAXLENGTH为最大字数
        }
    }
    
//    // textView高度自适应内容
//    CGSize textSize = CGSizeZero;
//    if (isIOS(7.0)) {
//        textSize = [self.textView sizeThatFits:CGSizeMake(kTextViewStringWidth, MAXFLOAT)];
//    }
//    else{
//        textSize = self.textView.contentSize;
//    }
//    
//    if (kTextViewHeight < textSize.height) {
//        [self.textView mas_updateConstraints:^(MASConstraintMaker *make) {
//            make.height.mas_equalTo(textSize.height);
//        }];
//        [UIView animateWithDuration:0.25 animations:^{
//            [self layoutIfNeeded];
//        }];
//    }else {
//        [self.textView mas_updateConstraints:^(MASConstraintMaker *make) {
//            make.height.mas_equalTo(kTextViewHeight);
//        }];
//    }
}

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{
    if (textView.markedTextRange == nil) {
        if (range.location >= kDescriptionMAXLength) {
            return NO;
        }
    }
    return YES;
}

#pragma mark - 键盘相关
// Handle keyboard show/hide changes
- (void)keyboardWillShow: (NSNotification *)notification {

    CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    
    UIInterfaceOrientation interfaceOrientation = [[UIApplication sharedApplication] statusBarOrientation];
    if (UIInterfaceOrientationIsLandscape(interfaceOrientation) && NSFoundationVersionNumber <= NSFoundationVersionNumber_iOS_7_1) {
        CGFloat tmp = keyboardSize.height;
        keyboardSize.height = keyboardSize.width;
        keyboardSize.width = tmp;
    }
    
    [self.whiteContainerView mas_updateConstraints:^(MASConstraintMaker *make) {
        make.centerY.mas_equalTo(-keyboardSize.height * 0.5);
    }];
    [UIView animateWithDuration:0.2f delay:0.0 options:UIViewAnimationOptionTransitionNone
                     animations:^{
                         [self layoutIfNeeded];
                     }
                     completion:nil
     ];
}

- (void)keyboardWillHide: (NSNotification *)notification {
    [self.whiteContainerView mas_updateConstraints:^(MASConstraintMaker *make) {
        make.centerY.mas_equalTo(0);
    }];
    [UIView animateWithDuration:0.2f delay:0.0 options:UIViewAnimationOptionTransitionNone
                     animations:^{
                         [self layoutIfNeeded];
                     }
                     completion:nil
     ];
}

- (void)show {
    [[UIApplication sharedApplication].keyWindow addSubview:self];
    //动画
    CGAffineTransform transform = CGAffineTransformMakeScale(1.2, 1.2);
    self.whiteContainerView.transform = transform;
    
    [UIView animateWithDuration:0.2 animations:^{
        self.bgCoverControl.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.5];
        self.whiteContainerView.alpha = 1; // 子控件的透明度跟着变化
        CGAffineTransform transform = CGAffineTransformMakeScale(1, 1);
        self.whiteContainerView.transform = transform;
    }];
}

- (void)dismiss {
    [UIView animateWithDuration:0.2 animations:^{
        self.bgCoverControl.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0];
        self.whiteContainerView.alpha = 0;
    } completion:^(BOOL finished) {
        [self removeFromSuperview];
    }];
}

-(void)setCancelString:(NSString *)cancelString {
    _cancelString = cancelString;
    [self.cancelButton setTitle:cancelString forState:UIControlStateNormal];
}

//****以下为解决第一次进入页面,textview不可滚动问题
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
    NSString * strText = self.textView.text;
    CGFloat h = [strText heightWithFont:[UIFont systemFontOfSize:16] withLineWidth:kTextViewStringWidth];
    self.textView.contentSize = CGSizeMake(0, h+10);
    
    return [super hitTest:point withEvent:event];
}

@end
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原文地址：https://www.cnblogs.com/tufei7/p/5830393.html