Web项目中导出数据的一个控件类

using System;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Drawing;

namespace WebHJControls

{

/// <summary>

/// Export 的摘要说明。

/// </summary>

public class WebExport: LinkButton

{

public WebExport()

{

//

// TODO: 在此处添加构造函数逻辑

//

}

protected override void OnClick(EventArgs e)

{

ExportButton_Click();

}

/// <summary>

/// 扩展名,在设置导出文件类型的时候同时设置

/// </summary>

private string ExtensionType

{

get

{

if(ViewState["ExtensionType"] == null)

return ".xls";

return (string)ViewState["ExtensionType"];

}

set

{

ViewState["ExtensionType"] = value;

}

}

/// <summary>

/// 要导出内容的目标控件ID,如果目标控件的父亲控件不是Page,那么应该从Page下的该控件的根控件开始传入,格式是ParentControlID.ControlID.ControlID...

/// </summary>

public string TargetControlID

{

get

{

if(ViewState["TargetControlID"] == null)

return String.Empty;

return (string)ViewState["TargetControlID"];

}

set

{

ViewState["TargetControlID"] = value;

}

}

/// <summary>

/// 文件类型

/// </summary>

public ExportFileType FileType

{

get

{

if(ViewState["ExportFileType"] == null)

return ExportFileType.Excel;

return (ExportFileType)ViewState["ExportFileType"];

}

set

{

ViewState["ExportFileType"] = value;

switch(value)

{

case ExportFileType.Excel:

this.ExtensionType = ".xls";

break;

case ExportFileType.Word:

this.ExtensionType = ".doc";

break;

case ExportFileType.html:

this.ExtensionType = ".html";

break;

default:

this.ExtensionType = ".xls";

break;

}

}

}

/// <summary>

/// 导出的文件名

/// </summary>

public string ExportFileName

{

get

{

if(ViewState["ExportFileName"] == null)

return "ExportFile";

return (string)ViewState["ExportFileName"];

}

set

{

ViewState["ExportFileName"] = value;

}

}

protected override void Render(HtmlTextWriter writer)

{

if(Page != null)

{

Page.VerifyRenderingInServerForm(this);

}

this.CausesValidation = false;

base.Render (writer);

}

private void ExportButton_Click()

{

//确保找到控件

Control c = AnalyseControlID();

if(c == null)

return;

HttpResponse response = HttpContext.Current.Response;

response.Clear();

response.Buffer= true;

response.ContentType = SetContentType();

response.AddHeader("Content-Disposition", "attachment; filename=" + ExportFileName + ExtensionType + "");

response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");

response.Charset = "gb2312";

EnableViewState = false;

System.IO.StringWriter oStringWriter = new System.IO.StringWriter();

System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);

ClearControls(c);

c.RenderControl(oHtmlTextWriter);

response.Write(oStringWriter.ToString());

response.End();

}

private string SetContentType()

{

string contentType = String.Empty;

switch(FileType)

{

case ExportFileType.Excel:

contentType = "application/vnd.ms-excel";

break;

case ExportFileType.Word:

contentType = "application/vnd.ms-word";

break;

case ExportFileType.html:

contentType = "application/txt";

break;

}

return contentType;

}

private Control AnalyseControlID()

{

if(Page != null)

{

string[] controlIDArray = TargetControlID.Split('.');

Control c = Page.FindControl(controlIDArray[0]);

for(int i = 1;i < controlIDArray.Length;i++)

{

c = c.FindControl(controlIDArray[i]);

}

return c;

}

return null;

}

public bool ThumbnailCallback()

{

return false;

}

/// <summary>

/// 清除可能产生回发的子控件变成文本控件,如果不这样做的话,调用RenderControl会产生错误

/// Reference:http://www.c-sharpcorner.com/Code/2003/Sept/ExportASPNetDataGridToExcel.asp

/// </summary>

/// <param name="control"></param>

private void ClearControls(Control control)

{

if(control is System.Web.UI.WebControls.Image)

{

// string vpath = ((System.Web.UI.WebControls.Image)control).ImageUrl;

// Uri baseUri = new Uri(vpath);

// string apath =this.Context.Server.MapPath(baseUri.AbsolutePath);

// System.Drawing.Image img = System.Drawing.Image.FromFile(apath);

// System.Drawing.Image.GetThumbnailImageAbort cbl = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);

// System.Drawing.Image newimg = img.GetThumbnailImage(100,150,cbl,IntPtr.Zero);

//newimg.Save(Response.OutputStream,System.Drawing.Imaging.ImageFormat.Gif);

}

if(control.ClientID.Equals("Photo"))

{

}

for (int i=control.Controls.Count -1; i>=0; i--)

{

ClearControls(control.Controls[i]);

}

if (!(control is TableCell))

{

if (control.GetType().GetProperty("SelectedItem") != null)

{

if(control.Parent != null)

{

LiteralControl literal = new LiteralControl();

control.Parent.Controls.Add(literal);

try

{

literal.Text = (string)control.GetType().GetProperty("SelectedItem").GetValue(control,null);//如果是处于选中状态的项

}

catch

{

}

control.Parent.Controls.Remove(control);

}

}

else if (control.GetType().GetProperty("Text") != null)

{

if(control.Parent != null)

{

LiteralControl literal = new LiteralControl();

control.Parent.Controls.Add(literal);

literal.Text = (string)control.GetType().GetProperty("Text").GetValue(control,null);

control.Parent.Controls.Remove(control);

}

}

}

return;

}

}

/// <summary>

/// 导出的文件类型

/// </summary>

public enum ExportFileType

{

Word = 1,

Excel = 2,

html = 3

}

}