如何在Swift3中更改UITextView中文本搅拌的颜色

Question

我在这里查看了一些现有的问题帖子,我试图实现所有代码,但最终无法成功实现任何代码.实际上,我认为UITextView如果最初设置文本,我理解如何更改内部某些文本的颜色,但我不明白的是,当我的文本tview开始进入编辑时,它似乎根本不能正常工作.在下面,我尝试的代码可以很好地满足我的期望行为;

 func textViewDidBeginEditing(_ textView: UITextView) {

    let main_string = ""
    let getData: [String] = userDefaults.object(forKey: "myData") as! [String]
    print("\(getData)")

    let searchWords = "world"

        let range = (main_string as NSString).range(of: searchWords)

        let attribute = NSMutableAttributedString.init(string: main_string)
        attribute.addAttribute(NSForegroundColorAttributeName, value: UIColor.red , range: range)

        mytextView.attributedText = attribute


}

我通过命名来保存输入数据UITextView.我尝试使用for循环来取出所有元素MyData并将其用作单个值.但是,在控制台中,有很多解释.我认为这是一种正确的写作方式,但我的mac说nooooooo.但是,如果我设置一个getData内部的String和main_string,例如,"这是我的问题.我想有人帮我世界"中main_string和"世界"在searchWords写在代码.然后在加载应用程序之后,在我的文本视图中,"世界"完全以红色突出显示,但在世界词之后,所有文本都是红色的.我不明白为什么我被这个未知的bug折磨.

所以我想要完成的是

1. 从我保存的日期开始searchWords,我只希望在用户输入时及时突出显示存储的单词.例如,如果用户键入"hello"和"world".然后它们被保存,myData只有在键入时它们才会被突出显示.当键入未存储的单词时,切换回正常颜色.

我想我缺乏一些解释.如果您需要了解某些信息,请指出.非常感谢!!

Answer 1

在这里我以字符串"世界"为例.当您在textview中输入时,此方法正在运行

func textViewDidChange(_ textView: UITextView) {
        let attrStr = NSMutableAttributedString(string:txtview.text)
        let inputLength = attrStr.string.characters.count
        let searchString = "world"
        let searchLength = searchString.characters.count
        var range = NSRange(location: 0, length: attrStr.length)

        while (range.location != NSNotFound) {
            range = (attrStr.string as NSString).range(of: searchString, options: [], range: range)
            if (range.location != NSNotFound) {
                attrStr.addAttribute(NSForegroundColorAttributeName, value: UIColor.red, range: NSRange(location: range.location, length: searchLength))
                range = NSRange(location: range.location + range.length, length: inputLength - (range.location + range.length))
                textView.attributedText = attrStr
            }
        }    
}

但是,当您已经设置了textview的初始文本时,请使用此方法

func textViewDidBeginEditing(_ textView: UITextView) {
        //Just set your text as you set in textview
        let attrStr = NSMutableAttributedString(string: "hello world I ma jeckjklwefljlwjflkjwfkljelwfjklfgjwklfjlkwgjwlgkjwklsgjklsjgklsdjgkljdslkgjsdlkgjlksdjgldjsgldjskl world nsfhjklshfklhsllsd fgiw world")
        let inputLength = attrStr.string.characters.count
        let searchString = "world"
        let searchLength = searchString.characters.count
        var range = NSRange(location: 0, length: attrStr.length)

        while (range.location != NSNotFound) {
            range = (attrStr.string as NSString).range(of: searchString, options: [], range: range)
            if (range.location != NSNotFound) {
                attrStr.addAttribute(NSForegroundColorAttributeName, value: UIColor.red, range: NSRange(location: range.location, length: searchLength))
                range = NSRange(location: range.location + range.length, length: inputLength - (range.location + range.length))
                textView.attributedText = attrStr
            }
          }  
  }

对于多字符串,您可以像这样SWIFT 3

func textViewDidChange(_ textView: UITextView) {
        let attrStr = NSMutableAttributedString(string: txtview.text)
        let inputLength = attrStr.string.characters.count
        let searchString : NSArray = NSArray.init(objects: "hello","world")
        for i in 0...searchString.count-1
        {

             let string : String = searchString.object(at: i) as! String
             let searchLength = string.characters.count
             var range = NSRange(location: 0, length: attrStr.length)

             while (range.location != NSNotFound) {
                 range = (attrStr.string as NSString).range(of: string, options: [], range: range)
                 if (range.location != NSNotFound) {
                 attrStr.addAttribute(NSForegroundColorAttributeName, value: UIColor.red, range: NSRange(location: range.location, length: searchLength))
                 range = NSRange(location: range.location + range.length, length: inputLength - (range.location + range.length))
                 textView.attributedText = attrStr
        }
    }   
  }
}

目标C
对于多个字符串,您可以这样做

-(void)textViewDidChange:(UITextView *)textView
{
    NSMutableAttributedString *attstr = [[NSMutableAttributedString alloc]initWithString:textView.text];
    NSUInteger characterCount = [attstr length];
    NSArray *arr = [[NSArray alloc]initWithObjects:@"football",@"player",nil];

    for (int i=0; i<arr.count; i++) {

    NSUInteger searchlength = [[NSString stringWithFormat:@"%@",[arr objectAtIndex:i]] length];
    NSRange range1 = NSMakeRange(0, attstr.length);

    while (range1.location != NSNotFound) {
        range1 =[attstr.string rangeOfString:[NSString stringWithFormat:@"%@",[arr objectAtIndex:i]] options:0 range:range1];
        if (range1.location !=NSNotFound) {
            [attstr addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(range1.location, searchlength)];
            [attstr addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:20.0]  range:range1];
            range1 = NSMakeRange(range1.location + range1.length, characterCount -(range1.location + range1.length));
            textView.attributedText = attstr;
        }
    }
}