iOS开发-UITextView字数限制方法-UITextView使用详细

来源：互联网发布：java编写计算器编辑：程序博客网时间：2024/05/29 13:50

TextView是我们常见的文本编辑框,在使用的时候很多人把他当做texfield使用，这是错误的,以下是textcview的使用，包括协议：在开头声明<UITextViewDelegate>

// 初始化text1 = [[UITextViewalloc]initWithFrame:CGRectMake(0,20, _vv2.frame.size.width,150)];text1.delegate =self;text1.textColor = [UIColorwhiteColor];text1.backgroundColor = [UIColorblackColor];text1.font = [UIFontsystemFontOfSize:16];// 用协议限制字数- (BOOL)textView:(UITextView *)atextView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{    if (range.location >50) {        returnNO;    }else    {        returnYES;    }}// textview的触发事件-(void)textViewDidChange:(UITextView *)textView{    NSInteger a;    a = 50 - textView.text.length;        if (a >=0) {        NSString * str = [NSStringstringWithFormat:@"还可以输入%ld字",a];        count.text = str;    }else    {        count.text =@"字数已满";    }        if (text1.text.length ==0) {        lable.text =@"请输入您的宝贵意见";    }else{        lable.text =@"";    }    NSLog(@"%ld",text1.text.length);}// 两个lable放在textview里面lable = [[UILabelalloc]initWithFrame:CGRectMake(0,5, 100,20)];lable.text =@"请输入内容";lable.textColor = [UIColorlightGrayColor];lable.font = [UIFontsystemFontOfSize:16];count = [[UILabelalloc]initWithFrame:CGRectMake(0,text1.frame.size.height -20, text1.frame.size.width - 100, 20)];count.text =@"还可以输入50字";count.textColor = [UIColorlightGrayColor];count.font = [UIFontsystemFontOfSize:16];

以下是效果图:

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