android 获取屏幕高度和宽度的方法

在开发过程中，我们通常需要获取Android手机或Pad的屏幕的物理尺寸，以便于界面的设计或是其他功能的实现。
步骤如下：
1. //定义DisplayMetrics 对象
DisplayMetrics dm = new DisplayMetrics();
2. //取得窗口属性
getWindowManager().getDefaultDisplay().getMetrics(dm);
3. //窗口的宽度
int screenWidth = dm.widthPixels;
//窗口高度
int screenHeight = dm.heightPixels;

另外，看到别人一个很好的获得屏幕相关的辅助类（from:【张鸿洋的博客】）

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Rect;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.WindowManager;

/** * 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;

    }

}