动态水晶报表实现

Question

我的绑定代码如下：
  objRpt = new CrystalReport3();            SqlConnection con = new SqlConnection("server=(local);uid=sa;pwd=123;database=db_CustomsTrade");
            con.Open();
            string sql = CreateSelectQueryAndParameters();
            if (!sql.Contains("Column"))
            {
                MessageBox.Show("No selection to display!");
                return;
            }
            SqlDataAdapter da = new SqlDataAdapter(sql, con);
            DataSet ds = new DataSet();
            da.Fill(ds, "tb_VendorPrint");
            con.Close();            objRpt.SetDataSource(ds);
            crystalReportViewer1.ReportSource = objRpt;

Answer 1

 public partial class Form3 : Form
    {
        public Form3()
        {
            InitializeComponent();
        }        CrystalReport3 objRpt;        private void crystalReportViewer1_Load(object sender, EventArgs e)
        {        }
        /// 本方法用于： 
        /// 1. 根据用户选定的字段名，创建 SELECT 查询
        /// 2. 与水晶报表中的参数字段相对应，创建参数并赋值给它们
        /// 说明: 根据用户的选择，这些参数用于显示水晶报表中的列名称（标题）
        /// 
        /// 
        private string CreateSelectQueryAndParameters()
        {
            ReportDocument reportDocument;
            ParameterFields paramFields;
            ParameterField paramField;
            ParameterDiscreteValue paramDiscreteValue;
            reportDocument = new ReportDocument();
            paramFields = new ParameterFields();
            string query = "SELECT ";
            int columnNo = 0;            if (checkBox1 .Checked )
            {
                columnNo++;
                query = query.Insert(query.Length, "VPCode as Column" + columnNo.ToString());
                paramField = new ParameterField();
                paramField.Name = "col" + columnNo.ToString();
                paramDiscreteValue = new ParameterDiscreteValue();
                paramDiscreteValue.Value = "VPCode";
                paramField.CurrentValues.Add(paramDiscreteValue);
                //把 paramField 添加到 paramFields 中
                paramFields.Add(paramField);
            }
            if (checkBox2.Checked)
            {
                columnNo++;
                if (query.Contains("Column"))
                {
                    query = query.Insert(query.Length, ", ");
                }
                query = query.Insert(query.Length, "VPShortName as Column" + columnNo.ToString());
                paramField = new ParameterField();
                paramField.Name = "col" + columnNo.ToString();
                paramDiscreteValue = new ParameterDiscreteValue();
                paramDiscreteValue.Value = "VPShortName";
                paramField.CurrentValues.Add(paramDiscreteValue);
                //把 paramField 添加到 paramFields
                paramFields.Add(paramField);
            }
            if (checkBox3.Checked)
            {
                columnNo++; //确定列的数目
                if (query.Contains("Column"))
                {
                    query = query.Insert(query.Length, ", ");
                }
                query = query.Insert(query.Length, "VPFullName as Column" + columnNo.ToString());
                paramField = new ParameterField();
                paramField.Name = "col" + columnNo.ToString();
                paramDiscreteValue = new ParameterDiscreteValue();
                paramDiscreteValue.Value = "VPFullName";
                paramField.CurrentValues.Add(paramDiscreteValue);
                //把 paramField 添加到 paramFields
                paramFields.Add(paramField);
            }
            if (checkBox4.Checked)
            {
                columnNo++;
                if (query.Contains("Column"))
                {
                    query = query.Insert(query.Length, ", ");
                }
                query = query.Insert(query.Length, "VPPhone as Column" + columnNo.ToString());
                paramField = new ParameterField();
                paramField.Name = "col" + columnNo.ToString();
                paramDiscreteValue = new ParameterDiscreteValue();
                paramDiscreteValue.Value = "VPPhone";
                paramField.CurrentValues.Add(paramDiscreteValue);
                //把 paramField 添加到 paramFields
                paramFields.Add(paramField);
            }
            
            //如果还有其他参数，为它们赋空值(empty value)
            for (int i = columnNo; i < 5; i++)
            {
                columnNo++;
                paramField = new ParameterField();
                paramField.Name = "col" + columnNo.ToString();
                paramDiscreteValue = new ParameterDiscreteValue();
                paramDiscreteValue.Value = "";
                paramField.CurrentValues.Add(paramDiscreteValue);
                //把 paramField 添加到 paramFields
                paramFields.Add(paramField);
            }
            crystalReportViewer1.ParameterFieldInfo = paramFields;
            query += " FROM tb_VendorPrint";
            return query;
        }        private void button1_Click(object sender, EventArgs e)
        {
            objRpt = new CrystalReport3();            SqlConnection con = new SqlConnection("server=(local);uid=sa;pwd=123;database=db_CustomsTrade");
            con.Open();
            string sql = CreateSelectQueryAndParameters();
            if (!sql.Contains("Column"))
            {
                MessageBox.Show("No selection to display!");
                return;
            }
            SqlDataAdapter da = new SqlDataAdapter(sql, con);
            DataSet ds = new DataSet();
            da.Fill(ds, "tb_VendorPrint");
            con.Close();            objRpt.SetDataSource(ds);
            crystalReportViewer1.ReportSource = objRpt;
               }    }
这是全部代码。