android dp和px转换

public class DensityUtils {

/**
* dp转px
*/
public static int dp2px(Context ctx, float dp) {
float density = ctx.getResources().getDisplayMetrics().density;
int px = (int) (dp * density + 0.5f);// 4.9->5 4.4->4

return px;
}

public static float px2dp(Context ctx, int px) {
float density = ctx.getResources().getDisplayMetrics().density;
float dp = px / density;

return dp;
}
}