1:  // Common .NET required namespaces

   2:  using System;

   3:  using System.ComponentModel;

   4:   

   5:  // WebPart required namespaces

   6:  using System.Web;

   7:  using System.Web.UI;

   8:  using System.Web.UI.WebControls;

   9:  using System.Web.UI.WebControls.WebParts;

  10:   

  11:  //Step #1: Reference the SharePoint namespace.

  12:  using Microsoft.SharePoint;

  13:   

  14:  namespace ConnectionCodeSamples.WebPartParametersProvider

  15:  {

  16:      // Step #2: Inherit from the WebPart base class and implement the 

  17:      // IWebPartParameters interface.

  18:      [ToolboxItemAttribute(false)]

  19:      public class WebPartParametersProvider : WebPart, IWebPartParameters

  20:      {

  21:          // Step #3: Declare private variables for configuration , handling 

  22:          // and a value passed as parameter.

  23:          private int _strFirst;

  24:          private int _strLength;

  25:          private string _myError = string.Empty;

  26:   

  27:          private string _urlData = "WebPartParametersProvider url 'data' value";

  28:   

  29:          // Step #4: the provider must implement a list of property descriptors 

  30:          // that the consumer is interested in 

  31:          private PropertyDescriptorCollection _objParameters;

  32:          public PropertyDescriptorCollection Parameters

  33:          {

  34:              get { return _objParameters; }

  35:              set { _objParameters = value; }

  36:          }

  37:   

  38:          // Step #5: Constructor

  39:          public WebPartParametersProvider()

  40:          {

  41:              this.ExportMode = WebPartExportMode.All;

  42:              base.Hidden = true;

  43:          }

  44:   

  45:          // Step #6: implement ConnectionInterface

  46:          [ConnectionProvider("my parameters provider")]

  47:          public IWebPartParameters ConnectionInterface()

  48:          {

  49:              return this;

  50:          }

  51:   

  52:          // Step #7: implement a schema for the data returned by the provider

  53:          // you need this for the IWebPart* interfaces

  54:          public System.ComponentModel.PropertyDescriptorCollection Schema

  55:          {

  56:              get

  57:              {

  58:                  PropertyDescriptorCollection objProperties;

  59:                  PropertyDescriptor[] arrProperties =

  60:                      new PropertyDescriptor[Parameters.Count];

  61:                  TypeDescriptor.GetProperties(this);

  62:   

  63:                  objProperties = TypeDescriptor.GetProperties(this);

  64:                  int intParameterCount = 0;

  65:                  foreach (PropertyDescriptor objProperty in Parameters)

  66:                  {

  67:                      if (Parameters[objProperty.Name] != null)

  68:                      {

  69:                          intParameterCount++;

  70:                          arrProperties[intParameterCount] = objProperty;

  71:                      }

  72:                  }

  73:   

  74:                  objProperties = new PropertyDescriptorCollection(arrProperties);

  75:                  return objProperties;

  76:              }

  77:          }

  78:   

  79:          // Step #8: implement a method called SetConsumerSchema(), allows a consumer

  80:          // to express its interest in a set of parameters provided by provider

  81:          public void SetConsumerSchema(System.ComponentModel.PropertyDescriptorCollection schema)

  82:          {

  83:              Parameters = schema;

  84:          }

  85:   

  86:          // Step #9: implement the GetParametersData(), this will hold a reference

  87:          // to the parameters consumer web part after a connection is established

  88:          public void GetParametersData(ParametersCallback callback)

  89:          {

  90:              StateBag objParameters = new StateBag();

  91:   

  92:              foreach (PropertyDescriptor objProperty in Parameters)

  93:              {

  94:                  switch (objProperty.Name)

  95:                  {

  96:                      case "data":

  97:                          objParameters.Add("data", UrlData);

  98:                          break;

  99:                      default:

 100:                          throw new Exception("WebPartParametersProvider: Unknown parameter name");

 101:                  }

 102:              }

 103:   

 104:              callback.Invoke(objParameters);

 105:          }

 106:   

 107:          // Step #10: implement properties for web part configuration 

 108:          // and to hold our data extracted from current url

 109:          [WebBrowsable(true),

 110:          Personalizable(PersonalizationScope.Shared),

 111:          WebDescription("The first char in web url to search for (0 based).")]

 112:          public int UrlFirst

 113:          {

 114:              get

 115:              {

 116:                  return this._strFirst;

 117:              }

 118:              set

 119:              {

 120:                  this._strFirst = value > 0 ? value : 0;

 121:              }

 122:          }

 123:   

 124:          [WebBrowsable(true),

 125:          Personalizable(PersonalizationScope.Shared),

 126:          WebDescription("The length of the string to extract after first char.")]

 127:          public int StrLength

 128:          {

 129:              get

 130:              {

 131:                  return this._strLength;

 132:              }

 133:              set

 134:              {

 135:                  this._strLength = value > 0 ? value : 0;

 136:              }

 137:          }

 138:   

 139:          public string UrlData

 140:          {

 141:              get { return _urlData; }

 142:              set { _urlData = value; }

 143:          }

 144:   

 145:          // Step #11: init the all data

 146:          protected override void OnInit(EventArgs e)

 147:          {

 148:              base.OnInit(e);

 149:   

 150:              if (UrlFirst != 0 && StrLength > 0)

 151:              {

 152:                  try

 153:                  {

 154:                      string url = SPContext.Current.Web.Url;

 155:                      if (url.Length >= UrlFirst + StrLength)

 156:                      {

 157:                          _urlData = url.Substring(UrlFirst, StrLength);

 158:                      }

 159:                  }

 160:                  catch (Exception se)

 161:                  {

 162:                      _myError = se.Message + ", " + se.InnerException;

 163:                  }

 164:              }

 165:          }

 166:   

 167:          // Step #12: create controls to show properies, 

 168:          // data and web part configuration hints in page edit mode

 169:          protected override void CreateChildControls()

 170:          {

 171:              Controls.Clear();

 172:   

 173:              if ((UrlFirst == 0 || StrLength == 0))

 174:              {

 175:                  //.. show a how to configure web part

 176:              }

 177:              else

 178:              {

 179:                  //.. show your properties and the assigned data

 180:              }

 181:          }

 182:      }

 183:  }