Ya me funciona, era la directiva using.
Código:
using PParalelo01.Properties;
Código:
private void checkBox_Pin1_D0_CheckedChanged(object sender, EventArgs e)
{
if (checkBox_Pin1_D0.Checked == true)
{
pictureBox_D0.Image = Resources.on;
}
if (checkBox_Pin1_D0.Checked == false)
{
pictureBox_D0.Image = Resources.off;
}
}
Muchas gracias honorable felix46.