是否有可能在TextView中设置文本跨度的颜色?

我想做一些类似于Twitter应用程序的事情,其中一部分文本是蓝色的。见下图:

(来源:twimg.com)


当前回答

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)

其他回答

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

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
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:

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

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)