Subscript and Superscript a String in Android

问题:

How can you print a string with a subscript or superscript? Can you do this without an external library? I want this to display in a TextView in Android.

回答1:

((TextView)findViewById(R.id.text)).setText(Html.fromHtml(\"X<sup>2</sup>\"));

or

Common Tasks and How to Do Them in Android

回答2:

Example:

equation = (TextView) findViewById(R.id.textView1);
SpannableStringBuilder cs = new SpannableStringBuilder(\"X3 + X2\");
cs.setSpan(new SuperscriptSpan(), 1, 2, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
cs.setSpan(new RelativeSizeSpan(0.75f), 1, 2, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
cs.setSpan(new SuperscriptSpan(), 6, 7, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
cs.setSpan(new RelativeSizeSpan(0.75f), 6, 7, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
equation.setText(cs);

回答3:

To all people asking, if you want to make it smaller besides of making super or subscript, you just need to add tag as well. EX:

\"X <sup><small> 2 </small></sup>\"

回答4:

If you want to set the superscript from string.xml file try this:

string resource:

<string name=\"test_string\">X&lt;sup&gt;3&lt;/sup&gt;</string>

if you want the superscript to be smaller:

<string name=\"test_string\">X&lt;sup&gt;&lt;small&gt;3&lt;/small&gt;&lt;/sup&gt;</string>

Code:

textView.setText(Html.fromHtml(\"Anything you want to put here\"+getString(R.string.test_string)));

回答5:

It bit late but following just work fine, use superscript as special character, I used spacial char here.

<string name=\"str\">H₂</string>

回答6:

((TextView)findViewById(R.id.text)).setText(Html.fromHtml(\"X<sup><small>2</small></sup>\")); 

(or) From String Resource File:

<string name=\"test_string\">
  <![CDATA[ X<sup><small>2</small></sup> ]]>
</string>

回答7:

In the code just put this \"\\u00B2\" Like this:

textView.setText(\"X\\u00B2\");

回答8:

The Accepted answer is deprecated now. So please go through this piece of code. I got this from some website. I forgot the name but anyway thanks for this good piece of working code.

     SpannableString styledString
            = new SpannableString(\"Large\\n\\n\"     // index 0 - 5
            + \"Bold\\n\\n\"          // index 7 - 11
            + \"Underlined\\n\\n\"    // index 13 - 23
            + \"Italic\\n\\n\"        // index 25 - 31
            + \"Strikethrough\\n\\n\" // index 33 - 46
            + \"Colored\\n\\n\"       // index 48 - 55
            + \"Highlighted\\n\\n\"   // index 57 - 68
            + \"K Superscript\\n\\n\" // \"Superscript\" index 72 - 83 
            + \"K Subscript\\n\\n\"   // \"Subscript\" index 87 - 96
            + \"Url\\n\\n\"           //  index 98 - 101
            + \"Clickable\\n\\n\");   // index 103 - 112

    // make the text twice as large
    styledString.setSpan(new RelativeSizeSpan(2f), 0, 5, 0);

    // make text bold
    styledString.setSpan(new StyleSpan(Typeface.BOLD), 7, 11, 0);

    // underline text
    styledString.setSpan(new UnderlineSpan(), 13, 23, 0);

    // make text italic
    styledString.setSpan(new StyleSpan(Typeface.ITALIC), 25, 31, 0);

    styledString.setSpan(new StrikethroughSpan(), 33, 46, 0);

    // change text color
    styledString.setSpan(new ForegroundColorSpan(Color.GREEN), 48, 55, 0);

    // highlight text
    styledString.setSpan(new BackgroundColorSpan(Color.CYAN), 57, 68, 0);

    // superscript
    styledString.setSpan(new SuperscriptSpan(), 72, 83, 0);
    // make the superscript text smaller
    styledString.setSpan(new RelativeSizeSpan(0.5f), 72, 83, 0);

    // subscript
    styledString.setSpan(new SubscriptSpan(), 87, 96, 0);
    // make the subscript text smaller
    styledString.setSpan(new RelativeSizeSpan(0.5f), 87, 96, 0);

    // url
    styledString.setSpan(new URLSpan(\"http://www.google.com\"), 98, 101, 0);

    // clickable text
    ClickableSpan clickableSpan = new ClickableSpan() {

        @Override
        public void onClick(View widget) {
            // We display a Toast. You could do anything you want here.
            Toast.makeText(MainActivity.this, \"Clicked\", Toast.LENGTH_SHORT).show();

        }
    };

    styledString.setSpan(clickableSpan, 103, 112, 0);


    // Give the styled string to a TextView
    spantext = (TextView) findViewById(R.id.spantext);


    // this step is mandated for the url and clickable styles.
    spantext.setMovementMethod(LinkMovementMethod.getInstance());

    // make it neat
    spantext.setGravity(Gravity.CENTER);
    spantext.setBackgroundColor(Color.WHITE);

    spantext.setText(styledString);

Note : Always put android:textAllCaps=\"false\" of your spantext.

回答9:

I found this article on how to use a Spannable or in a string resource file: <sup> or <sub> for superscript and subscript, respectively.

回答10:

The HTML.fromHTML(String) was deprecated as of API 24. They say to use this one instead, which supports flags as a parameter. So to go off of the accepted answer:

TextView textView = ((TextView)findViewById(R.id.text));
textView.setText(Html.fromHtml(\"X<sup>2</sup>\", Html.FROM_HTML_MODE_LEGACY));

And if you want code that considers pre-24 API\'s as well:

TextView textView = ((TextView)findViewById(R.id.text));
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
  textView.setText(Html.fromHtml(\"X<sup>2</sup>\", Html.FROM_HTML_MODE_LEGACY));
} else {
    textView.setText(Html.fromHtml(\"X<sup>2</sup>\"));    
}

This answer was derived from: https://stackoverflow.com/a/37905107/4998704

The flags and other documentation can be found here: https://developer.android.com/reference/android/text/Html.html

回答11:

They are called Unicode characters, and Android TextView supports them. Copy the super/sub-script you want from this Wiki: https://en.wikipedia.org/wiki/List_of_Unicode_characters#Superscripts_and_Subscripts

回答12:

In the strings.xml files, you can just use the HTML <sup>3</sup> tag. Work perfectly for me

EXAMPLE

<string name=\"turnoverRate\">Turnover rate m<sup>3</sup>/m<sup>2</sup>/hour:</string>

回答13:

yourTextView.setText(Html.fromHtml(\"X<sup>2</sup>\"));

This will be the result in you yourTextView =

X²