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

First Part **Second Part should be Bold** last Part

此文本应该使用SpannableString进行更改

import android.graphics.Typeface.BOLD
import android.text.Spannable
import android.text.Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
import android.text.SpannableString
import android.text.style.BackgroundColorSpan
import android.text.style.ForegroundColorSpan
import android.text.style.StyleSpan

val firstPart = "First Part  "
val secondPart = "Second Part should be Bold"
val thirdPart = "  last Part"
val finalString = firstPart + secondPart + thirdPart

val sb: Spannable = SpannableString(finalString).also {
                // ... Change text Colour
                it.setSpan(
                    ForegroundColorSpan(getColor(requireContext(), R.color.pink)),
                    finalString.indexOf(secondPart),
                    finalString.indexOf(secondPart) + secondPart.length,
                    SPAN_EXCLUSIVE_EXCLUSIVE
                )
                // ... Make the text Bold
                it.setSpan(
                    StyleSpan(BOLD),
                    finalString.indexOf(secondPart),
                    finalString.indexOf(secondPart) + secondPart.length,
                    SPAN_EXCLUSIVE_EXCLUSIVE
                )
                // ... Change Background Colour
                it.setSpan(
                    BackgroundColorSpan(getColor(requireContext(), R.color.lightPink)),
                    finalString.indexOf(secondPart) - 1,
                    finalString.indexOf(secondPart) + secondPart.length + 1,
                    SPAN_EXCLUSIVE_EXCLUSIVE
                )
}

yourTextView.text = sb

从开发人员文档中，更改一个可伸缩对象的颜色和大小:

1-创建类:

    class RelativeSizeColorSpan(size: Float,@ColorInt private val color: Int): RelativeSizeSpan(size) {

    override fun updateDrawState(textPaint: TextPaint?) {
        super.updateDrawState(textPaint)
        textPaint?.color = color
    } 
}

2 .使用该类创建你的spannable:

    val spannable = SpannableStringBuilder(titleNames)
spannable.setSpan(
    RelativeSizeColorSpan(1.5f, Color.CYAN), // Increase size by 50%
    titleNames.length - microbe.name.length, // start
    titleNames.length, // end
    Spannable.SPAN_EXCLUSIVE_INCLUSIVE
)

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");

String text = "I don't like Hasina.";
textView.setText(spannableString(text, 8, 14));

private SpannableString spannableString(String text, int start, int end) {
    SpannableString spannableString = new SpannableString(text);
    ColorStateList redColor = new ColorStateList(new int[][]{new int[]{}}, new int[]{0xffa10901});
    TextAppearanceSpan highlightSpan = new TextAppearanceSpan(null, Typeface.BOLD, -1, redColor, null);

    spannableString.setSpan(highlightSpan, start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    spannableString.setSpan(new BackgroundColorSpan(0xFFFCFF48), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    spannableString.setSpan(new RelativeSizeSpan(1.5f), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

    return spannableString;
}

输出:

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)