namespace _3.Label和TextBox控件使用
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

    private void textBox1_TextChanged(object sender, EventArgs e)
    {
        //![](https://cache.tdyun.com/upload/information/20200311/60/233837.jpg?x-oss-process=image/watermark,size_16,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_90,type_ZmFuZ3poZW5naGVpdGk=)给TextBox注册一个事件，当文本框改变时赋值给Label
       label1.Text= textBox1.Text;
    }
}

}