前言：关于屏幕长、宽、高的一些简单操作。

/**
 * 获得屏幕相关的辅助类
 * 
 * @author zhy
 * 
 */
public class ScreenUtils
{
    private ScreenUtils()
    {
        /* cannot be instantiated */
        throw new UnsupportedOperationException("cannot be instantiated");
    }

    /**
     * 获得屏幕高度
     * 
     * @param context
     * @return
     */
    public static int getScreenWidth(Context context)
    {
        WindowManager wm = (WindowManager) context
                .getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics outMetrics = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(outMetrics);
        return outMetrics.widthPixels;
    }

    /**
     * 获得屏幕宽度
     * 
     * @param context
     * @return
     */
    public static int getScreenHeight(Context context)
    {
        WindowManager wm = (WindowManager) context
                .getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics outMetrics = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(outMetrics);
        return outMetrics.heightPixels;
    }

    /**
     * 获得状态栏的高度
     * 
     * @param context
     * @return
     */
    public static int getStatusHeight(Context context)
    {

        int statusHeight = -1;
        try
        {
            Class<?> clazz = Class.forName("com.android.internal.R$dimen");
            Object object = clazz.newInstance();
            int height = Integer.parseInt(clazz.getField("status_bar_height")
                    .get(object).toString());
            statusHeight = context.getResources().getDimensionPixelSize(height);
        } catch (Exception e)
        {
            e.printStackTrace();
        }
        return statusHeight;
    }

    /**
     * 获取当前屏幕截图，包含状态栏
     * 
     * @param activity
     * @return
     */
    public static Bitmap snapShotWithStatusBar(Activity activity)
    {
        View view = activity.getWindow().getDecorView();
        view.setDrawingCacheEnabled(true);
        view.buildDrawingCache();
        Bitmap bmp = view.getDrawingCache();
        int width = getScreenWidth(activity);
        int height = getScreenHeight(activity);
        Bitmap bp = null;
        bp = Bitmap.createBitmap(bmp, 0, 0, width, height);
        view.destroyDrawingCache();
        return bp;

    }

    /**
     * 获取当前屏幕截图，不包含状态栏
     * 
     * @param activity
     * @return
     */
    public static Bitmap snapShotWithoutStatusBar(Activity activity)
    {
        View view = activity.getWindow().getDecorView();
        view.setDrawingCacheEnabled(true);
        view.buildDrawingCache();
        Bitmap bmp = view.getDrawingCache();
        Rect frame = new Rect();
        activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
        int statusBarHeight = frame.top;

        int width = getScreenWidth(activity);
        int height = getScreenHeight(activity);
        Bitmap bp = null;
        bp = Bitmap.createBitmap(bmp, 0, statusBarHeight, width, height
                - statusBarHeight);
        view.destroyDrawingCache();
        return bp;

    }

}

public static class ScreenUtil {
        /**
         * 获得屏幕高度
         *
         * @param context
         * @return
         */
        public static int getPxWidth(Context context) {
            WindowManager wm = (WindowManager) context
                    .getSystemService(Context.WINDOW_SERVICE);
            DisplayMetrics outMetrics = new DisplayMetrics();
            wm.getDefaultDisplay().getMetrics(outMetrics);
            return outMetrics.widthPixels;
        }

        /**
         * 获得屏幕宽度
         *
         * @param context
         * @return
         */
        public static int getPxHeight(Context context) {
            WindowManager wm = (WindowManager) context
                    .getSystemService(Context.WINDOW_SERVICE);
            DisplayMetrics outMetrics = new DisplayMetrics();
            wm.getDefaultDisplay().getMetrics(outMetrics);
            return outMetrics.heightPixels;
        }

        /**
         * 获得屏幕高度
         *
         * @param context
         * @return
         */
        public static int getDpWidth(Context context) {
            WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
            DisplayMetrics dm = new DisplayMetrics();
            wm.getDefaultDisplay().getMetrics(dm);
            int width = dm.widthPixels;         // 屏幕宽度（像素）
//            int height = dm.heightPixels;       // 屏幕高度（像素）
            float density = dm.density;         // 屏幕密度（0.75 / 1.0 / 1.5）
//            int densityDpi = dm.densityDpi;     // 屏幕密度dpi（120 / 160 / 240）
            // 屏幕宽度算法:屏幕宽度（像素）/屏幕密度
            int dpWidth = (int) (width / density);  // 屏幕宽度(dp)
//            int screenHeight = (int) (height / density);// 屏幕高度(dp)
            return dpWidth;
        }

        /**
         * 获得屏幕宽度
         *
         * @param context
         * @return
         */
        public static int getDpHeight(Context context) {
            WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
            DisplayMetrics dm = new DisplayMetrics();
            wm.getDefaultDisplay().getMetrics(dm);
//            int width = dm.widthPixels;         // 屏幕宽度（像素）
            int height = dm.heightPixels;       // 屏幕高度（像素）
            float density = dm.density;         // 屏幕密度（0.75 / 1.0 / 1.5）
//            int densityDpi = dm.densityDpi;     // 屏幕密度dpi（120 / 160 / 240）
            // 屏幕宽度算法:屏幕宽度（像素）/屏幕密度
//            int screenWidth = (int) (width / density);  // 屏幕宽度(dp)
            int dpHeight = (int) (height / density);// 屏幕高度(dp)
            return dpHeight;
        }

        /**
         * 根据手机的分辨率从 dp 的单位 转成为 px(像素)
         */
        public static int dip2px(Context context, float dpValue) {
            final float scale = context.getResources().getDisplayMetrics().density;
            return (int) (dpValue * scale + 0.5f);
        }

        /**
         * 根据手机的分辨率从 px(像素) 的单位 转成为 dp
         */
        public static int px2dip(Context context, float pxValue) {
            final float scale = context.getResources().getDisplayMetrics().density;
            return (int) (pxValue / scale + 0.5f);
        }
    }