Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
501 views
in Technique[技术] by (71.8m points)

user interface - Add text to image in android programmatically

I want to make an application just like opening screen of android.I am dynamically adding images to the rows of tableLayout. I have only defined tableLayout in xml file and remaining code is in java. I have added images successfully but i am not getting any help with setting text of that image (I want to display a text under image) and image to be a specific padding.How to do it?Thanks in advance.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

Use the following function to write Text on Images:

private BitmapDrawable writeTextOnDrawable(int drawableId, String text) {

    Bitmap bm = BitmapFactory.decodeResource(getResources(), drawableId)
            .copy(Bitmap.Config.ARGB_8888, true);

    Typeface tf = Typeface.create("Helvetica", Typeface.BOLD);

    Paint paint = new Paint();
    paint.setStyle(Style.FILL);
    paint.setColor(Color.WHITE);
    paint.setTypeface(tf);
    paint.setTextAlign(Align.CENTER);
    paint.setTextSize(convertToPixels(mContext, 11));

    Rect textRect = new Rect();
    paint.getTextBounds(text, 0, text.length(), textRect);

    Canvas canvas = new Canvas(bm);

    //If the text is bigger than the canvas , reduce the font size
    if(textRect.width() >= (canvas.getWidth() - 4))     //the padding on either sides is considered as 4, so as to appropriately fit in the text
        paint.setTextSize(convertToPixels(mContext, 7));        //Scaling needs to be used for different dpi's

    //Calculate the positions
    int xPos = (canvas.getWidth() / 2) - 2;     //-2 is for regulating the x position offset

    //"- ((paint.descent() + paint.ascent()) / 2)" is the distance from the baseline to the center.
    int yPos = (int) ((canvas.getHeight() / 2) - ((paint.descent() + paint.ascent()) / 2)) ;  

    canvas.drawText(text, xPos, yPos, paint);

    return new BitmapDrawable(getResources(), bm);
}



public static int convertToPixels(Context context, int nDP)
{
    final float conversionScale = context.getResources().getDisplayMetrics().density;

    return (int) ((nDP * conversionScale) + 0.5f) ;

}

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

2.1m questions

2.1m answers

60 comments

57.0k users

...