在 TextView 中更改一个单词的文本颜色

我正在寻找一种方法,以改变颜色的文本的一个单词在一个 TextView从一个 Activity

例如:

String first = "This word is ";
String next = "red"
TextView t = (TextView) findViewById(R.id.textbox);
t.setText(first + next);

如何将 next文本的颜色更改为红色?

107358 次浏览

Easiest way I know is to just use html.

String first = "This word is ";
String next = "<font color='#EE0000'>red</font>";
t.setText(Html.fromHtml(first + next));

But this will require you to rebuild the TextView when (if?) you want to change the color, which could cause a hassle.

t.setText(first + next, BufferType.SPANNABLE);
Spannable s = (Spannable)t.getText();
int start = first.length();
int end = start + next.length();
s.setSpan(new ForegroundColorSpan(0xFFFF0000), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

you have to use spannable this will also allows you to increase some text's size, make it bold etc.... even put in some image.

If you want to change the state of all the instances of a specific String inside a TextView text(case insensitive) you can use StringBuilders and SpannableString like this:

StringBuilder textBuilder = new StringBuilder(myTextView.getText().toString());
StringBuilder searchedTextBuilder = new StringBuilder((mySearchedString));
SpannableString spannableString = new SpannableString(myTextView.getText().toString());


int counter = 0;
int index = 0;


for (int i = 0;i < textBuilder.length() - mySearchedString.length() - 1;i++)
{
counter = 0;
if (Character.toLowerCase(textBuilder.charAt(i)) == Character.toLowerCase(searchedTextBuilder.charAt(index)))
{
counter++;
index++;
for (int j = 1,z = i + 1;j < mySearchedString.length() - 1;j++,z++)
{
if (Character.toLowerCase(textBuilder .charAt(z)) == Character.toLowerCase(searchedTextBuilder .charAt(index)))
{
counter++;
index++;
}
else
{
index++;
if (index % mySearchedString.length() == 0)
{
index = 0;
}
break;
}
}
if (counter == mySearchedString.length() - 1) // A match
{
spannableString.setSpan(new ForegroundColorSpan(Color.RED), i,
i + mySearchedString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); // Do the change you want(In this case changing the fore ground color to red)
index = 0;
continue;
}
else
{
index = 0;
continue;
}
}
}
myTextView.setText(spannableString);

}

  • Store the whole TextView text inside a StringBuilder.
  • Store the searched string inside a StringBuilder.
  • Store the wholre TextView text inside a SpannableString
  • Make a simple operation to find all the String instances inside the TextView text and change them when reached.
  • Set the text value of the TextView to the SpannableString.

Use SpannableStringBuilder like this :

SpannableStringBuilder builder = new SpannableStringBuilder();


SpannableString str1= new SpannableString("Text1");
str1.setSpan(new ForegroundColorSpan(Color.RED), 0, str1.length(), 0);
builder.append(str1);


SpannableString str2= new SpannableString(appMode.toString());
str2.setSpan(new ForegroundColorSpan(Color.GREEN), 0, str2.length(), 0);
builder.append(str2);


TextView tv = (TextView) view.findViewById(android.R.id.text1);
tv.setText( builder, TextView.BufferType.SPANNABLE);

for long string you can use this:

String help = getString(R.string.help);
help = help.replace("some word", "<font color='#EE0000'>some word</font>");
txtDesc.setText(Html.fromHtml(help));

I implemented a utility function in Kotlin for my own usecase and maybe useful for someone else.

fun getCusomTextWithSpecificTextWithDiffColor(textToBold: String, fullText: String,
targetColor: Int) =
SpannableStringBuilder(fullText).apply {
setSpan(ForegroundColorSpan(targetColor),
fullText.indexOf(textToBold),
(fullText.indexOf(textToBold) + textToBold.length),
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE)
}

How I am using it:

context?.let {
infoMessage.text = AppUtils.getCusomTextWithSpecificTextWithDiffColor(
wordAsBold,
completeSentence, ContextCompat.getColor(it, R.color.white))
}

USE:

makeTextBold("Your order is accepted","accepted", textView);
makeTextBold("Your order is canceled","canceled", textView);

Function:

public static void makeTextBold(String sentence, String word, AppCompatTextView textView) {
SpannableStringBuilder builder = new SpannableStringBuilder();
int startIndex = sentence.indexOf(word.toLowerCase().trim());
int endIndex = startIndex + word.toLowerCase().trim().length();
SpannableString spannableString = new SpannableString(sentence);
StyleSpan boldSpan = new StyleSpan(Typeface.BOLD);
spannableString.setSpan(boldSpan, startIndex, endIndex, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); //To make text Bold
spannableString.setSpan(new ForegroundColorSpan(Color.RED), startIndex, endIndex, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); //To change color of text
builder.append(spannableString);
textView.setText(builder, TextView.BufferType.SPANNABLE);
}

I think this is more readable for coloring a word in a string it is also probably more efficient a bit because you write once

    String str  = YOUR_STRING
Spannable s = new SpannableString(str);
int start = str.indexOf(err_word_origin);
int end =  start + err_word_origin.length();
s.setSpan(new ForegroundColorSpan(Color.BLUE), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
YOUR_TEXT_VIEW.setText(s , TextView.BufferType.SPANNABLE);

my solution extension:

    fun coloredText(
baseText: String,
coloredText: String,
targetColor: Int
): SpannableStringBuilder {
val transformText = "$baseText $coloredText"
return SpannableStringBuilder(transformText).apply {
setSpan(
ForegroundColorSpan(targetColor),
transformText.indexOf(coloredText),
(transformText.indexOf(coloredText) + coloredText.length),
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
)
}
}

Usage

binding.mytextView.title = coloredText(
baseText = getString(R.string.my_title),
coloredText = getString(R.string.my_title_colored_part),
targetColor = ContextCompat.getColor(requireContext(), R.color.blue))

Iv'e found this best answer https://stackoverflow.com/a/53573169/14250778 just changed one line to support also words that starts with uppercase letter

public void setHighLightedText(TextView tv, String textToHighlight) {
// added "toLowerCase()" to support words that starts with uppercase letter
String tvt = tv.getText().toString().toLowerCase();
int ofe = tvt.indexOf(textToHighlight, 0);
Spannable wordToSpan = new SpannableString(tv.getText());
for (int ofs = 0; ofs < tvt.length() && ofe != -1; ofs = ofe + 1) {
ofe = tvt.indexOf(textToHighlight, ofs);
if (ofe == -1)
break;
else {
// set color here
wordToSpan.setSpan(new BackgroundColorSpan(0xFFFFFF00), ofe, ofe + textToHighlight.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
tv.setText(wordToSpan, TextView.BufferType.SPANNABLE);
}
}
}