how to make a specific text on TextView BOLD

Solution 1:

Just build your String in HTML and set it:

String sourceString = "<b>" + id + "</b> " + name; 
mytextview.setText(Html.fromHtml(sourceString));

Solution 2:

While you can use Html.fromHtml() you can use a more native approach which is SpannableStringBuilder , this post may be helful.

SpannableStringBuilder str = new SpannableStringBuilder("Your awesome text");
str.setSpan(new android.text.style.StyleSpan(android.graphics.Typeface.BOLD), INT_START, INT_END, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
TextView tv=new TextView(context);
tv.setText(str);

Solution 3:

First: You don't need to worry about using the slow performance code from the Raghav Sood's answer.

Second: You don't need to write an extension function provided by w3bshark's answer when using Kotlin.

Finnaly: All you need to do is to use the Kotlin android-ktx library from Google (refer here to find more information and how to include it on your project):

// Suppose id = 1111 and name = neil (just what you want). 
val s = SpannableStringBuilder()
          .bold { append(id) } 
          .append(name)
txtResult.setText(s) 

Produces: 1111 neil

UPDATE:

Because I think it can help someone else as well as to demonstrate how far you can go here are more use cases.

• When you need to display a text with some parts in blue and italic:

  val myCustomizedString = SpannableStringBuilder()
      .color(blueColor, { append("A blue text ") })
      .append("showing that ")
      .italic{ append("it is painless") }
  

• When you need to display a text in both bold and italic:

      bold { italic { append("Bold and italic") } }
  

In short, bold, append, color and italic are extension functions to SpannableStringBuilder. You can see another extension functions in the official documentation, from where you can think for other possibilities.

Solution 4:

I thought that the chosen answer didn't provide a satisfactory result. I have written my own function which takes 2 strings; The full text and the part of the text you want to make bold.

It returns a SpannableStringBuilder with the 'textToBold' from 'text' bolded.

I find the ability to make a substring bold without wrapping it in tags useful.

    /**
     * Makes a substring of a string bold.
     * @param text          Full text
     * @param textToBold    Text you want to make bold
     * @return              String with bold substring
     */

    public static SpannableStringBuilder makeSectionOfTextBold(String text, String textToBold){

        SpannableStringBuilder builder=new SpannableStringBuilder();

        if(textToBold.length() > 0 && !textToBold.trim().equals("")){

            //for counting start/end indexes
            String testText = text.toLowerCase(Locale.US);
            String testTextToBold = textToBold.toLowerCase(Locale.US);
            int startingIndex = testText.indexOf(testTextToBold);
            int endingIndex = startingIndex + testTextToBold.length();
            //for counting start/end indexes

            if(startingIndex < 0 || endingIndex <0){
                return builder.append(text);
            }
            else if(startingIndex >= 0 && endingIndex >=0){

                builder.append(text);
                builder.setSpan(new StyleSpan(Typeface.BOLD), startingIndex, endingIndex, 0);
            }
        }else{
            return builder.append(text);
        }

        return builder;
  }