您可以通过扩展ReplacementSpan创建自己的跨度。在draw
方法中,您可以考虑fontSpacing
可以从Paint
参数中获取的内容。
像这样:
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.FontMetricsInt;
import android.graphics.RectF;
import android.text.style.ReplacementSpan;
public class BetterHighlightSpan extends ReplacementSpan {
private int backgroundColor;
public BetterHighlightSpan(int backgroundColor) {
super();
this.backgroundColor = backgroundColor;
}
@Override
public int getSize(Paint paint, CharSequence text, int start, int end, FontMetricsInt fm) {
return Math.round(paint.measureText(text, start, end));
}
@Override
public void draw(Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom,
Paint paint) {
// save current color
int oldColor = paint.getColor();
// calculate new bottom position considering the fontSpacing
float fontSpacing = paint.getFontSpacing();
float newBottom = bottom - fontSpacing;
// change color and draw background highlight
RectF rect = new RectF(x, top, x + paint.measureText(text, start, end), newBottom);
paint.setColor(backgroundColor);
canvas.drawRect(rect, paint);
// revert color and draw text
paint.setColor(oldColor);
canvas.drawText(text, start, end, x, y, paint);
}
}
你可以像这样使用它:
TextView textView = (TextView) findViewById(R.id.textView);
SpannableStringBuilder builder = new SpannableStringBuilder("here some text and more of it");
builder.setSpan(new BetterHighlightSpan(Color.CYAN), 4, 8, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(builder);
我无法对其进行太多测试,但您可以改进它。