另一个答案将非常相似，但不需要设置TextView的文本两次

TextView TV = (TextView)findViewById(R.id.mytextview01);

Spannable wordtoSpan = new SpannableString("I know just how to whisper, And I know just how to cry,I know just where to find the answers");        

wordtoSpan.setSpan(new ForegroundColorSpan(Color.BLUE), 15, 30, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

TV.setText(wordtoSpan);

这是一个帮助函数。当你有多种语言的时候非常有用!

private void setColor(TextView view, String fulltext, String subtext, int color) {
    view.setText(fulltext, TextView.BufferType.SPANNABLE);
    Spannable str = (Spannable) view.getText();
    int i = fulltext.indexOf(subtext);
    str.setSpan(new ForegroundColorSpan(color), i, i + subtext.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
}

通过传递String和Color在文本上设置颜色:

private String getColoredSpanned(String text, String color) {
  String input = "<font color=" + color + ">" + text + "</font>";
  return input;
}

通过调用下面的代码设置TextView / Button / EditText等文本:

TextView:

TextView txtView = (TextView)findViewById(R.id.txtView);

获取彩色字符串:

String name = getColoredSpanned("Hiren", "#800000");

在TextView上设置文本:

txtView.setText(Html.fromHtml(name));

Done

另一个答案将非常相似，但不需要设置TextView的文本两次

TextView TV = (TextView)findViewById(R.id.mytextview01);

Spannable wordtoSpan = new SpannableString("I know just how to whisper, And I know just how to cry,I know just where to find the answers");        

wordtoSpan.setSpan(new ForegroundColorSpan(Color.BLUE), 15, 30, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

TV.setText(wordtoSpan);

您可以在Kotlin中使用扩展函数

fun CharSequence.colorizeText(
    textPartToColorize: CharSequence,
    @ColorInt color: Int
): CharSequence = SpannableString(this).apply {
    val startIndexOfText = this.indexOf(textPartToColorize.toString())
    setSpan(ForegroundColorSpan(color), startIndexOfText, startIndexOfText.plus(textPartToColorize.length), 0)
}

用法:

val colorizedText = "this text will be colorized"
val myTextToColorize = "some text, $colorizedText continue normal text".colorizeText(colorizedText,ContextCompat.getColor(context, R.color.someColor))
viewBinding.myTextView.text = myTextToColorize

当我试图理解一个新概念时，我总是发现视觉例子很有帮助。

背景颜色

SpannableString spannableString = new SpannableString("Hello World!");
BackgroundColorSpan backgroundSpan = new BackgroundColorSpan(Color.YELLOW);
spannableString.setSpan(backgroundSpan, 0, spannableString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(spannableString);

前景颜色

SpannableString spannableString = new SpannableString("Hello World!");
ForegroundColorSpan foregroundSpan = new ForegroundColorSpan(Color.RED);
spannableString.setSpan(foregroundSpan, 0, spannableString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(spannableString);

结合

SpannableString spannableString = new SpannableString("Hello World!");
ForegroundColorSpan foregroundSpan = new ForegroundColorSpan(Color.RED);
BackgroundColorSpan backgroundSpan = new BackgroundColorSpan(Color.YELLOW);
spannableString.setSpan(foregroundSpan, 0, 8, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannableString.setSpan(backgroundSpan, 3, spannableString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(spannableString);

进一步的研究

解释SPAN_EXCLUSIVE_EXCLUSIVE等Span标志的含义 Android Spanned, SpannedString, Spannable, SpannableString和CharSequence