give text color and font size in android string

To give text a color and font size in an Android app, you can use the SpannableStringBuilder class to create a SpannableString with the desired formatting, and then set the SpannableString as the text of a TextView.

Here's an example of how you could use the SpannableStringBuilder class to set the text color and font size of a TextView in an Android layout:

import android.graphics.Color;
import android.text.SpannableStringBuilder;
import android.text.style.AbsoluteSizeSpan;
import android.text.style.ForegroundColorSpan;
import android.widget.TextView;

TextView textView = findViewById(R.id.text_view);
SpannableStringBuilder builder = new SpannableStringBuilder();

String text = "Hello, world!";
builder.append(text);

int start = 0;
int end = text.length();
builder.setSpan(new ForegroundColorSpan(Color.RED), start, end, 0);
builder.setSpan(new AbsoluteSizeSpan(20), start, end, 0);

textView.setText(builder);

In this example, the ForegroundColorSpan and AbsoluteSizeSpan classes are used to set the text color and font size, respectively. The setSpan() method is used to apply the spans to the SpannableStringBuilder, and the setText() method is used to set the SpannableStringBuilder as the text of the TextView.

Note that you can use different span classes to apply different types of formatting to text, such as background color, font style, or underline.