C#中时间类型的应用

public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
MessageBox.Show(DateTime.Now.ToLocalTime().ToString());
}
private void button2_Click(object sender, EventArgs e)
{
MessageBox.Show(DateTime.Now.ToLocalTime().ToShortDateString() );
}
private void button3_Click(object sender, EventArgs e)
{
MessageBox.Show(DateTime.Now.ToLocalTime().Year.ToString());
}

private void button4_Click(object sender, EventArgs e)
{
DateTime d1, d2;
d1 = Convert.ToDateTime(textBox1.Text);
d2 =Convert.ToDateTime( textBox2.Text);
if (d1 > d2)
MessageBox.Show("d1>d2");
else if(d2>d1)
MessageBox.Show("d2>d1");
else if (d2 ==d1)
MessageBox.Show("d2=d1");
}
}