不多说，直接上代码
@interface THTextView () <UITextViewDelegate>
@property (strong, nonatomic) UILabel *surplusLbl; // 剩余可输入字数
@property (strong, nonatomic) UILabel *placeholderLbl; // 占位文字
@property (assign, nonatomic) NSInteger maxLength; // 最大文字长度
@property (assign, nonatomic) CGFloat textViewH; // 初始化时的textView高度
@property (weak, nonatomic) UIView *subView; // 父控件
@end
@implementation THTextView
/**
初始化方法
@param frame 尺寸
@param subView 父控件
@param title textView 内容文本
@param place 占位文字
@param maxLength 最大文字长度
*/
- (instancetype)initWithFrame:(CGRect)frame subView:(UIView *)subView title:(NSString *)title place:(NSString *)place maxLength:(NSInteger)maxLength
{
self = [super initWithFrame:frame];
if (self) {
self.maxLength = maxLength;
self.textViewH = frame.size.height;
self.subView = subView;
self.layer.cornerRadius = 5;
self.font = [UIFont systemFontOfSize:14];
self.backgroundColor = [UIColor whiteColor];
self.delegate = self;
[self configSurplusLbl];
[self configPlaceholderLbl];
// 如果有内容文本，就让占位文字隐藏，计算可输入字数
if (title) {
self.placeholderLbl.hidden = YES;
self.attributedText = [self textViewAttributedStr:title];
self.surplusLbl.text = [NSString stringWithFormat:@"%ld/%ld", maxLength - title.length, maxLength];
} else {
self.placeholderLbl.hidden = NO;
self.placeholderLbl.text = place;
self.surplusLbl.text = [NSString stringWithFormat:@"%ld/%ld", maxLength, maxLength];
}
// 如果textView的contentSize.height的高度大于初始化高度，就更新textView的实际高度，更新剩余可输入字数的Y值
if (frame.size.height < self.contentSize.height) {
frame.size.height = self.contentSize.height;
self.frame = frame;
self.surplusLbl.top = CGRectGetMaxY(frame) + 10;
}
// 监听键盘改变的通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textViewKeyboardWillChangeFrame:) name:UIKeyboardWillChangeFrameNotification object:nil];
}
return self;
}
// 返回文本格式
- (NSAttributedString *)textViewAttributedStr:(NSString *)text {
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = 5;// 字体的行间距
NSDictionary *attributes = @{
NSFontAttributeName:[UIFont systemFontOfSize:14],
NSParagraphStyleAttributeName:paragraphStyle
};
return [[NSAttributedString alloc] initWithString:text attributes:attributes];
}
#pragma mark - UITextViewDelegate
// 计算剩余可输入字数 超出最大可输入字数，就禁止输入
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{
// 设置占位文字是否隐藏
if(![text isEqualToString:@""]) {
[self.placeholderLbl setHidden:YES];
}
if([text isEqualToString:@""] && range.length == 1 && range.location == 0){
[self.placeholderLbl setHidden:NO];
}
UITextRange *selectedRange = [textView markedTextRange];
//获取高亮部分
UITextPosition *pos = [textView positionFromPosition:selectedRange.start offset:0];
//获取高亮部分内容
//NSString * selectedtext = [textView textInRange:selectedRange];
//如果有高亮且当前字数开始位置小于最大限制时允许输入
if (selectedRange && pos) {
NSInteger startOffset = [textView offsetFromPosition:textView.beginningOfDocument toPosition:selectedRange.start];
NSInteger endOffset = [textView offsetFromPosition:textView.beginningOfDocument toPosition:selectedRange.end];
NSRange offsetRange = NSMakeRange(startOffset, endOffset - startOffset);
if (offsetRange.location < self.maxLength) {
return YES;
}else{
return NO;
}
}
NSString *comcatstr = [textView.text stringByReplacingCharactersInRange:range withString:text];
NSInteger caninputlen = self.maxLength - comcatstr.length;
if (caninputlen >= 0){
return YES;
}else{
NSInteger len = text.length + caninputlen;
//防止当text.length + caninputlen < 0时，使得rg.length为一个非法最大正数出错
NSRange rg = {0, MAX(len, 0)};
if (rg.length > 0){
// 因为我的是不需要输入表情，所以没有计算表情的宽度
// NSString *s =@"";
// //判断是否只普通的字符或asc码(对于中文和表情返回NO)
// BOOL asc = [text canBeConvertedToEncoding:NSASCIIStringEncoding];
// if (asc) {
// s = [text substringWithRange:rg];//因为是ascii码直接取就可以了不会错
// }else{
// __block NSInteger idx = 0;
// __block NSString *trimString =@"";//截取出的字串
// //使用字符串遍历，这个方法能准确知道每个emoji是占一个unicode还是两个
// [text enumerateSubstringsInRange:NSMakeRange(0, [text length]) options:NSStringEnumerationByComposedCharacterSequences usingBlock: ^(NSString* substring,NSRange substringRange,NSRange enclosingRange,BOOL* stop) {
// if (idx >= rg.length) {
// *stop =YES;//取出所需要就break，提高效率
// return ;
// }
// trimString = [trimString stringByAppendingString:substring];
// idx++;
// }];
// s = trimString;
// }
//rang是指从当前光标处进行替换处理(注意如果执行此句后面返回的是YES会触发didchange事件)
[textView setAttributedText: [self textViewAttributedStr:[textView.text stringByReplacingCharactersInRange:range withString:[text substringWithRange:rg]]]];
//既然是超出部分截取了，哪一定是最大限制了。
self.surplusLbl.text = [NSString stringWithFormat:@"%d/%ld",0,(long)self.maxLength];
}
return NO;
}
}
- (void)textViewDidChange:(UITextView *)textView{
UITextRange *selectedRange = [textView markedTextRange];
//获取高亮部分
UITextPosition *pos = [textView positionFromPosition:selectedRange.start offset:0];
//如果在变化中是高亮部分在变，就不要计算字符了
if (selectedRange && pos) {
return;
}
NSString *nsTextContent = textView.text;
NSInteger existTextNum = nsTextContent.length;
if (existTextNum > self.maxLength){
//截取到最大位置的字符(由于超出截部分在should时被处理了所在这里这了提高效率不再判断)
NSString *s = [nsTextContent substringToIndex:self.maxLength];
[textView setAttributedText: [self textViewAttributedStr:s]];
}
//不让显示负数
self.surplusLbl.text = [NSString stringWithFormat:@"%ld/%ld",MAX(0,self.maxLength - existTextNum),self.maxLength];
// 自动增加textView的高度
// CGRect bouns = textView.bounds;
// CGSize maxSize = CGSizeMake(bouns.size.width, CGFLOAT_MAX);
// CGSize newSize = [textView sizeThatFits:maxSize];
// NSLog(@"%@", NSStringFromCGSize(self.size));
// if (newSize.height > self.height) {
// textView.height = newSize.height + 20;
// self.surplusLbl.top = textView.height - 20;
// self.placeholderLbl.top = CGRectGetMaxY(textView.frame);
// }
//不支持系统表情的输入
if ([NSString isStringContainsEmoji:textView.text]) {
[[UIViewController currentViewController] showInfo:@"不支持输入表情，请重新输入!"];
self.text = [textView.text substringToIndex:textView.text.length - 2];
}
}
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView {
if (textView.text.length > 0) {
self.placeholderLbl.hidden = YES;
} else {
self.placeholderLbl.hidden = NO;
}
return YES;
}
pragma mark - 通知
/** 键盘frame即将改变的通知 */
- (void)textViewKeyboardWillChangeFrame:(NSNotification *)notification {
NSDictionary *userInfo = notification.userInfo;
double duration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
CGRect keyboardF = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
[UIView animateWithDuration:duration animations:^{
// 键盘下去了
if (keyboardF.origin.y >= mScreenHeight) {
CGRect frame = self.frame;
if (frame.size.height < self.contentSize.height) {
frame.size.height = self.contentSize.height;
self.frame = frame;
self.surplusLbl.top = CGRectGetMaxY(self.frame) + 10;
}
// 键盘上来了
} else {
CGRect frame = self.frame;
frame.size.height = self.textViewH;
self.frame = frame;
self.surplusLbl.top = CGRectGetMaxY(self.frame) + 10;
}
}];
}
// 限制输入表情
+ (BOOL)isStringContainsEmoji:(NSString *)string {
__block BOOL returnValue = NO;
[string enumerateSubstringsInRange:NSMakeRange(0, [string length])
options:NSStringEnumerationByComposedCharacterSequences
usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop)
{
const unichar hs = [substring characterAtIndex:0];
if (0xd800 <= hs && hs <= 0xdbff) {
if (substring.length > 1) {
const unichar ls = [substring characterAtIndex:1];
const int uc = ((hs - 0xd800) * 0x400) + (ls - 0xdc00) + 0x10000;
if (0x1d000 <= uc && uc <= 0x1f77f) {
returnValue = YES;
}
}
} else if (substring.length > 1) {
const unichar ls = [substring characterAtIndex:1];
if (ls == 0x20e3) {
returnValue = YES;
}
} else {
if (0x2100 <= hs && hs <= 0x27ff) {
returnValue = YES;
} else if (0x2B05 <= hs && hs <= 0x2b07) {
returnValue = YES;
} else if (0x2934 <= hs && hs <= 0x2935) {
returnValue = YES;
} else if (0x3297 <= hs && hs <= 0x3299) {
returnValue = YES;
} else if (hs == 0xa9 || hs == 0xae || hs == 0x303d || hs == 0x3030 || hs == 0x2b55 || hs == 0x2b1c || hs == 0x2b1b || hs == 0x2b50) {
returnValue = YES;
}
}
}];
return returnValue;
}
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