屏幕和尺寸单位

public static int getWidth(Context context){
DisplayMetrics displayMetrics=new DisplayMetrics();
//获取windowManager
WindowManager windowManager= (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
windowManager.getDefaultDisplay().getMetrics(displayMetrics);
//获取的宽度的像素值
int width=displayMetrics.widthPixels;
return width;
}

public static int getHeight(Context context){
DisplayMetrics displayMetrics=new DisplayMetrics();
//获取windowManager
WindowManager windowManager= (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
windowManager.getDefaultDisplay().getMetrics(displayMetrics);
//获取的高度的像素值
int width=displayMetrics.heightPixels;
return width;
}

/**
* dp转像素
* @param context
* @param dp
* @return
*/
public static int  dp2Px(Context context,float dp)
{
DisplayMetrics displayMetrics=new DisplayMetrics();
//获取WindowManager
WindowManager windowManager= (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
windowManager.getDefaultDisplay().getMetrics(displayMetrics);
//缩放因子 density
float density=displayMetrics.density;

return (int) (density*dp+0.5f);
}

/**
* 像素转dp
* @param context
* @param px
* @return
*/
public static int px2Dp(Context context,float px)
{
DisplayMetrics displayMetrics=new DisplayMetrics();
WindowManager windowManager= (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
windowManager.getDefaultDisplay().getMetrics(displayMetrics);
float density=displayMetrics.density;//缩放因子
return (int) (px / density + 0.5f);
}