关于Android设备屏幕大小及密度的系统参数类

关于Android设备屏幕大小及密度的系统参数类

功能

获取Android设备屏幕宽、高、dpi密度及横竖屏等参数

代码

/**
 * 系统参数类
 *
 * @author wader
 *
 */
public class MySystemParams {
 private final String TAG = "SystemParams";
 private static MySystemParams params;
 public int screenWidth;// 屏幕宽度，单位为px
 public int screenHeight;// 屏幕高度，单位为px
 public int densityDpi;// 屏幕密度，单位为dpi
 public float scale;// 缩放系数，值为 densityDpi/160
 public float fontScale;// 文字缩放系数，同scale

 public final static int SCREEN_ORIENTATION_VERTICAL = 1; // 屏幕状态：横屏
 public final static int SCREEN_ORIENTATION_HORIZONTAL = 2; // 屏幕状态：竖屏
 public int screenOrientation = SCREEN_ORIENTATION_VERTICAL;// 当前屏幕状态，默认为竖屏

 /**
  * 私有构造方法
  *
  * @param activity
  */
 private MySystemParams(Activity activity) {
  DisplayMetrics dm = new DisplayMetrics();
  activity.getWindowManager().getDefaultDisplay().getMetrics(dm);
  screenWidth = dm.widthPixels;
  screenHeight = dm.heightPixels;
  densityDpi = dm.densityDpi;
  scale = dm.density;
  fontScale = dm.scaledDensity;

  screenOrientation = screenHeight > screenWidth ? SCREEN_ORIENTATION_VERTICAL
    : SCREEN_ORIENTATION_HORIZONTAL;
 }

 /**
  * 获取实例
  *
  * @param activity
  * @return
  */
 public static MySystemParams getInstance(Activity activity) {
  if (params == null) {
   params = new MySystemParams(activity);
  }
  return params;
 }

 /**
  * 获取一个新实例
  *
  * @param activity
  * @return
  */
 public static MySystemParams getNewInstance(Activity activity) {
  if (params != null) {
   params = null;
  }
  return getInstance(activity);
 }

 /**
  * 参数信息
  */
 public String toString() {

  return TAG
    + ":[screenWidth: "
    + screenWidth
    + " screenHeight: "
    + screenHeight
    + " scale: "
    + scale
    + " fontScale: "
    + fontScale
    + " densityDpi: "
    + densityDpi
    + " screenOrientation: "
    + (screenOrientation == SCREEN_ORIENTATION_VERTICAL ? "vertical"
      : "horizontal") + "]";
 }
}