1.校验只能输入数字、小数点、退格键的代码

   private void TextBoxKeyPress(object sender, KeyPressEventArgs e)
        {
            //================48代表0，57代表9，8代表退格删除，46代表小数点
            if ((e.KeyChar <= 48 || e.KeyChar >= 57) && (e.KeyChar != 8) && (e.KeyChar != 46))
                e.Handled = true;

        }

View Code 2.在需要调用的地方调用

    private void Frm_Load(object sender, EventArgs e)
        {
            //校验只能输入数字
            this.txtCount.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.TextBoxKeyPress);
        }

View Code