巧用报表工具API的一个示例

　　每个报表工具都号称自己拥有完善的API，但是大叔测试过如此多的报表开发工具，大多都将报表设计和报表分开的，报表查看器封装得太完整了，经常需要的动态报表功能都不能实现了。

　　在ActiveReports的官博上看到说他们能创建动态区段报表，步骤大概以下几步：

1. 创建一个报表实例
2. 动态的添加区段和控件
3. 修改报表区段和控件的相关细节
4. 给报表指派设置数据源
5. 将报表绑定到数据源

　　下面将一个简单的示例代码分享

private void Form1_Load(object sender, EventArgs e)
{
   rpt = new SectionReport();
  
   //Adding Page Header/Footer sections
   rpt.Sections.InsertPageHF();
   rpt.Sections[0].BackColor = Color.LightGray;
  
   //Adding Detail section
   rpt.Sections.Insert(1, new Detail());
   rpt.Sections[1].BackColor = Color.PeachPuff;
   rpt.Sections[1].Height = 1.5f;
  
   //Adding label to display first column's name
   GrapeCity.ActiveReports.SectionReportModel.Label lblCategoryID = new GrapeCity.ActiveReports.SectionReportModel.Label();
   lblCategoryID.Location = new PointF(0, 0.05F);
   lblCategoryID.Text = "Category ID";
   lblCategoryID.Alignment = GrapeCity.ActiveReports.Document.Section.TextAlignment.Center;
   lblCategoryID.Font = new System.Drawing.Font("Arial", 10, FontStyle.Bold);
   rpt.Sections[0].Controls.Add(lblCategoryID);
  
   //Adding label to display second column's name
   GrapeCity.ActiveReports.SectionReportModel.Label lblCategoryName = new GrapeCity.ActiveReports.SectionReportModel.Label();
   lblCategoryName.Location = new PointF(1.459f, 0.05f);
   lblCategoryName.Size = new SizeF(1.094f,0.2f);
   lblCategoryName.Text = "Category Name";
   lblCategoryName.Font = new System.Drawing.Font("Arial", 10, FontStyle.Bold);
   rpt.Sections[0].Controls.Add(lblCategoryName);
  
   //Adding label to display third column's name
   GrapeCity.ActiveReports.SectionReportModel.Label lblDescription = new GrapeCity.ActiveReports.SectionReportModel.Label();
   lblDescription.Location = new PointF(3.114f, 0.05f);
   lblDescription.Text = "Description";
   lblDescription.Font = new System.Drawing.Font("Arial", 10, FontStyle.Bold);
   rpt.Sections[0].Controls.Add(lblDescription);
  
   //Adding label to display fourth column's name
   GrapeCity.ActiveReports.SectionReportModel.Label lblPicture = new GrapeCity.ActiveReports.SectionReportModel.Label();
   lblPicture.Location = new PointF(5.219f, 0.05f);
   lblPicture.Alignment = GrapeCity.ActiveReports.Document.Section.TextAlignment.Center;
   lblPicture.Text = "Picture";
   lblPicture.Font = new System.Drawing.Font("Arial", 10, FontStyle.Bold);
   rpt.Sections[0].Controls.Add(lblPicture);
  
   //Adding Textbox to display first column's records
   GrapeCity.ActiveReports.SectionReportModel.TextBox txtCategoryID = new GrapeCity.ActiveReports.SectionReportModel.TextBox();
   txtCategoryID.Location = new PointF(0,0);
   txtCategoryID.Alignment = GrapeCity.ActiveReports.Document.Section.TextAlignment.Center;
   rpt.Sections[1].Controls.Add(txtCategoryID);
  
   //Adding Textbox to display second column's records
   GrapeCity.ActiveReports.SectionReportModel.TextBox txtCategoryName = new GrapeCity.ActiveReports.SectionReportModel.TextBox();
   txtCategoryName.Location = new PointF(1.459f,0);
   rpt.Sections[1].Controls.Add(txtCategoryName);
  
   //Adding Textbox to display third column's records
   GrapeCity.ActiveReports.SectionReportModel.TextBox txtDescription = new GrapeCity.ActiveReports.SectionReportModel.TextBox();
   txtDescription.Location = new PointF(3.114f,0);
   rpt.Sections[1].Controls.Add(txtDescription);
  
   //Adding Picture control to display image
   GrapeCity.ActiveReports.SectionReportModel.Picture picture = new Picture();
   picture.Location = new PointF(5.219f,0);
   rpt.Sections[1].Controls.Add(picture);
  
   // Setting report's data source
   conn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\stduser\Documents\ComponentOne Samples\ActiveReports Developer 7\Data\NWIND.mdb;Persist Security Info=False");
   System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand("SELECT * FROM Categories", conn);
   conn.Open();
   reader = cmd.ExecuteReader();
   rpt.DataSource = reader;
  
   // Assigning DataField properties of controls in the detail section
   txtCategoryID.DataField = "CategoryID";
   txtCategoryName.DataField = "CategoryName";
   txtDescription.DataField = "Description";
   picture.DataField = "Picture";
   reader.Close();
   conn.Close();
}

　　在安装ActiveReports后，修改动态区段的时候用到以上代码，顺便给一个ActiveReports的下载>> ，想要测试的下载了看看效果。