C# Dictionary.TryGetValue方法代码示例

			protected override SelectQuery ProcessQuery(SelectQuery selectQuery)
			{
				if (selectQuery.IsInsert && selectQuery.Insert.Into.Name == "Parent")
				{
					var expr =
						new QueryVisitor().Find(selectQuery.Insert, e =>
						{
							if (e.ElementType == QueryElementType.SetExpression)
							{
								var se = (SelectQuery.SetExpression)e;
								return ((SqlField)se.Column).Name == "ParentID";
							}

							return false;
						}) as SelectQuery.SetExpression;

					if (expr != null)
					{
						var value = ConvertTo<int>.From(((IValueContainer)expr.Expression).Value);

						if (value == 555)
						{
							var tableName = "Parent1";
							var dic       = new Dictionary<IQueryElement,IQueryElement>();

							selectQuery = new QueryVisitor().Convert(selectQuery, e =>
							{
								if (e.ElementType == QueryElementType.SqlTable)
								{
									var oldTable = (SqlTable)e;

									if (oldTable.Name == "Parent")
									{
										var newTable = new SqlTable(oldTable) { Name = tableName, PhysicalName = tableName };

										foreach (var field in oldTable.Fields.Values)
											dic.Add(field, newTable.Fields[field.Name]);

										return newTable;
									}
								}

								IQueryElement ex;
								return dic.TryGetValue(e, out ex) ? ex : null;
							});
						}
					}
				}

				return selectQuery;
			}

        private void Clone(Dictionary<MapNode, MapNode> originalToClone)
        {
            //Add yourself to lookup
            MapNode thisClone;
            if (!originalToClone.TryGetValue(this, out thisClone)) //Determines if this MapNode has been visited yet
            {
                thisClone = new MapNode(this.Color);
                originalToClone.Add(this, thisClone);
                //Add neighbors to lookup
                foreach (MapNode neighbor in _neighbors)
                {
                    neighbor.Clone(originalToClone); //guarentees the neighbor will be in the lookup
                    MapNode neighborClone = originalToClone[neighbor];
                    if (!thisClone._neighbors.Contains(neighborClone))
                        thisClone._neighbors.Add(neighborClone);
                }

            }
        }

        public void CategoryLoad(DataTable dt)
        {
            Dictionary<int, string> dicCategoryMap = new Dictionary<int, string>();

            if (File.Exists(_categoryMapFilePath))
            {
                IEnumerable<string> listCategoryMap = File.ReadLines(_categoryMapFilePath);

                string[] columns;
                foreach (string categoryMap in listCategoryMap)
                {
                    columns = categoryMap.Split('|');
                    dicCategoryMap.Add(int.Parse(columns[0]), columns[1]);
                }
            }

            _indexId = dt.Columns.IndexOf("CID");
            _indexName = dt.Columns.IndexOf("CName");
            _indexFolderName = dt.Columns.IndexOf("FolderName");
            _indexParentId = dt.Columns.IndexOf("FID");
            _indexType = dt.Columns.IndexOf("CType");
            _indexIsExistVideo = dt.Columns.IndexOf("IsVideo");
            _indexIsExistVector = dt.Columns.IndexOf("IsVector");
            _indexStoreTableName = dt.Columns.IndexOf("DataTable");
            _indexIsDetail = dt.Columns.IndexOf("IsDetail");

            Category categoryRoot = new Category();
            categoryRoot.Id = 0;
            categoryRoot.LevelPath = string.Empty;
            categoryRoot.LevelCategory = string.Empty;
            categoryRoot.FolderName = string.Empty;

            string localDirectoryPath;
            dicCategoryMap.TryGetValue(categoryRoot.Id, out localDirectoryPath);
            categoryRoot.LocalDirectoryPath = localDirectoryPath;

            TreeNode nodeRoot = new TreeNode();
            nodeRoot.ImageIndex = (int)ImageIndex.Root;
            nodeRoot.SelectedImageIndex = (int)ImageIndex.Root;
            nodeRoot.Text = "分类目录";
            nodeRoot.Expand();
            nodeRoot.Tag = categoryRoot;
            _treeCategory.Nodes.Clear();
            _treeCategory.Nodes.Add(nodeRoot);

            GreateTree(dt, "0", nodeRoot, ref dicCategoryMap);
        }

        /// <summary>
        /// Import a CSV file which contains Chapter Names
        /// </summary>
        /// <param name="dataChpt">
        /// The DataGridView Control
        /// </param>
        /// <param name="filename">
        /// The filepath and name
        /// </param>
        /// <returns>A Populated DataGridView</returns>
        public static DataGridView ImportChapterNames(DataGridView dataChpt, string filename)
        {
            IDictionary<int, string> chapterMap = new Dictionary<int, string>();
            try
            {
                StreamReader sr = new StreamReader(filename);
                string csv = sr.ReadLine();
                while (csv != null)
                {
                    if (csv.Trim() != string.Empty)
                    {
                        csv = csv.Replace("\\,", "<!comma!>");
                        string[] contents = csv.Split(',');
                        int chapter;
                        int.TryParse(contents[0], out chapter);
                        chapterMap.Add(chapter, contents[1].Replace("<!comma!>", ","));
                    }
                    csv = sr.ReadLine();
                }
            }
            catch (Exception)
            {
                return null;
            }

            foreach (DataGridViewRow item in dataChpt.Rows)
            {
                string name;
                chapterMap.TryGetValue((int)item.Cells[0].Value, out name);
                item.Cells[1].Value = name ?? "Chapter " + item.Cells[0].Value;
            }

            return dataChpt;
        }

        private void GreateTree(DataTable dt, string parentId, TreeNode parentNode, ref Dictionary<int, string> dicCategoryMap)
        {
            DataView dv = new DataView(dt);

            dv.RowFilter = "FID = '" + parentId + "'";

            foreach (DataRowView drv in dv)
            {
                Category category = new Category();
                category.Id = Convert.ToInt32(drv[_indexId]);
                category.Name = drv[_indexName].ToString();
                category.FolderName = drv[_indexFolderName].ToString();
                category.ParentId = Convert.ToInt32(drv[_indexParentId]);
                category.Type = (CategoryType)Convert.ToByte(drv[_indexType]);
                category.IsExistVideo = Convert.ToBoolean(drv[_indexIsExistVideo]);
                category.IsThumbSquare = Convert.ToBoolean(drv[_indexIsExistVector]);
                category.StoreTableName = drv[_indexStoreTableName].ToString();
                category.IsDetail = Convert.ToBoolean(drv[_indexIsDetail]);
                category.LevelPath = (parentNode.Tag as Category).LevelPath + "|" + category.FolderName;
                category.LevelCategory = (parentNode.Tag as Category).LevelCategory + "_" + category.Name;

                string localDirectoryPath;
                dicCategoryMap.TryGetValue(category.Id, out localDirectoryPath);
                category.LocalDirectoryPath = localDirectoryPath;

                int indexImage = (int)ImageIndex.UnKnowType;
                if (string.IsNullOrEmpty(category.LocalDirectoryPath) || !Directory.Exists(category.LocalDirectoryPath))
                {
                    indexImage = (int)ImageIndex.NoBind;
                }
                else if (category.Type == CategoryType.Picture)
                {
                    indexImage = category.IsDetail ? (int)ImageIndex.PictureDetail : (int)ImageIndex.Picture;
                }
                else if (category.Type == CategoryType.Gallery)
                {
                    indexImage = category.IsDetail ? (int)ImageIndex.GalleryDetail : (int)ImageIndex.Gallery;
                }

                TreeNode newTreeNode = new TreeNode();
                newTreeNode.ImageIndex = indexImage;
                newTreeNode.SelectedImageIndex = indexImage;
                newTreeNode.Text = category.Name;
                newTreeNode.Tag = category;
                parentNode.Nodes.Add(newTreeNode);

                GreateTree(dt, category.Id.ToString(), newTreeNode, ref dicCategoryMap);
            }
        }