//在构造pictureBox控件的代码区(Form1.Desingner.cs)写入
this.pictureBox1.Click += new System.EventHandler(this.pictureBox1_Click);
//双击窗体设计器进入代码区写入
private void pictureBox1_Click(object sender, EventArgs e)
{
MessageBox.Show("这样就可以了");
}