android不同屏幕之间像素和dip的转换比例是不一样的：

    2 px = 3 dip if dpi == 80(ldpi), 320x240 screen

    1 px = 1 dip if dpi == 160(mdpi), 480x320 screen

    3 px = 2 dip if dpi == 240(hdpi), 840x480

方法：

// dip转像素 public int DipToPixels(Context context, int dip) { final float SCALE = context.getResources().getDisplayMetrics().density; float valueDips = dip; int valuePixels = (int) (valueDips * SCALE + 0.5f); return valuePixels; } // 像素转dip public float PixelsToDip(Context context, int Pixels) { final float SCALE = context.getResources().getDisplayMetrics().density; float dips = Pixels / SCALE; return dips; }