这是一个Kotlin扩展函数

    fun TextView.setColouredSpan(word: String, color: Int) {
        val spannableString = SpannableString(text)
        val start = text.indexOf(word)
        val end = text.indexOf(word) + word.length
        try {
            spannableString.setSpan(ForegroundColorSpan(color), start, end,Spannable.SPAN_EXCLUSIVE_EXCLUSIVE)
            text = spannableString
        } catch (e: IndexOutOfBoundsException) {
         println("'$word' was not not found in TextView text")
    }
}

使用它后，你已经设置你的文本到TextView，就像这样

private val blueberry by lazy { getColor(R.color.blueberry) }

textViewTip.setColouredSpan("Warning", blueberry)

有一个用于创建Spannable的工厂，并避免强制转换，就像这样:

Spannable span = Spannable.Factory.getInstance().newSpannable("text");

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

设置你的TextView的文本跨度，并为你的文本定义一个ForegroundColorSpan。

TextView textView = (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);    
textView.setText(wordtoSpan);

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);

下面的内容非常适合我

    tvPrivacyPolicy = (TextView) findViewById(R.id.tvPrivacyPolicy);
    String originalText = (String)tvPrivacyPolicy.getText();
    int startPosition = 15;
    int endPosition = 31;

    SpannableString spannableStr = new SpannableString(originalText);
    UnderlineSpan underlineSpan = new UnderlineSpan();
    spannableStr.setSpan(underlineSpan, startPosition, endPosition, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);

    ForegroundColorSpan backgroundColorSpan = new ForegroundColorSpan(Color.BLUE);
    spannableStr.setSpan(backgroundColorSpan, startPosition, endPosition, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);

    StyleSpan styleSpanItalic  = new StyleSpan(Typeface.BOLD);

    spannableStr.setSpan(styleSpanItalic, startPosition, endPosition, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);

    tvPrivacyPolicy.setText(spannableStr);

以上代码的输出