private void button1_Click(object sender, EventArgs e)
        {
            
            string str = textBox1.Text;
            //Clipboard.SetDataObject(str);//将数据粘贴到剪贴板
            Clipboard.SetData(DataFormats.Text ,str);//以指定的格式，将数据粘贴到剪贴板



        }

        private void button2_Click(object sender, EventArgs e)
        {
            IDataObject iData = Clipboard.GetDataObject();

            // Determines whether the data is in a format you can use.
            if (iData.GetDataPresent(DataFormats.Text))
            {
                // Yes it is, so display it in a text box.
                textBox2.Text = (String)iData.GetData(DataFormats.Text);
            }
            else
            {
                // No it is not.
                textBox2.Text = "Could not retrieve data off the clipboard.";
            }

        }