android获取屏幕像素

private void alertScreenDialog() {DisplayMetrics dm = new DisplayMetrics();getWindowManager().getDefaultDisplay().getMetrics(dm);String optStr = "手机屏幕分辨率为: "+dm.widthPixels+" x "+dm.heightPixels;Builder builder = new Builder(this);builder.setMessage(optStr);builder.setIcon(R.drawable.firefox);builder.setTitle("获取屏幕像素");//点击确定按钮builder.setPositiveButton("确定", new DialogInterface.OnClickListener(){@Overridepublic void onClick(DialogInterface dialog, int which) {Toast.makeText(GetScreenActivity.this, "获取到像素", Toast.LENGTH_LONG).show();}});builder.setNegativeButton("返回", new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {Toast.makeText(GetScreenActivity.this, "返回", Toast.LENGTH_LONG).show();}});builder.create().show();}