如何在Android中以编程方式更改位图的高度和宽度？

Question

I want to resize the bitmap height & width into same as the user device width & height.So please help me if u know the code.Thank You !

This is my code:

 Bitmap bm = BitmapFactory.decodeResource(getResources(),R.drawable.nature);

DisplayMetrics metrics = getApplicationContext().getResources().getDisplayMetrics();
width = metrics.widthPixels;
height=metrics.heightPixels;

But it was not working

Answer 1

Try to use this method:

public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {
    // GET CURRENT SIZE
    int width = bm.getWidth();
    int height = bm.getHeight();
    // GET SCALE SIZE
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;
    // CREATE A MATRIX FOR THE MANIPULATION
    Matrix matrix = new Matrix();
    // RESIZE THE BIT MAP
    matrix.postScale(scaleWidth, scaleHeight);
    // "RECREATE" THE NEW BITMAP
    Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);
    return resizedBitmap;
}

Answer 2

Bitmap.createScaledBitmap works great. As the document :

Creates a new bitmap, scaled from an existing bitmap, when possible. If the specified width and height are the same as the current width and height of the source bitmap, the source bitmap is returned and no new bitmap is created.