C# MSBuildEvaluationContext.SetItemContext方法代码示例

		internal static bool ExecuteStringTransform (List<MSBuildItemEvaluated> evaluatedItemsCollection, MSBuildEvaluationContext context, string transformExp, out string items)
		{
			// This method works mostly like ExecuteTransform, but instead of returning a list of items, it returns a string as result.
			// Since there is no need to create full blown evaluated items, it can be more efficient than ExecuteTransform.

			items = "";

			string itemName, expression, itemFunction; object [] itemFunctionArgs;
			if (!ParseTransformExpression (context, transformExp, out itemName, out expression, out itemFunction, out itemFunctionArgs))
				return false;

			var transformItems = evaluatedItemsCollection.Where (i => i.Name == itemName).ToArray ();
			if (itemFunction != null) {
				string result; bool ignoreMetadata;
				if (ExecuteSummaryItemFunction (transformItems, itemFunction, itemFunctionArgs, out result)) {
					// The item function returns a value. Just return it.
					items = result;
					return true;
				} else if (ExecuteTransformItemListFunction (ref transformItems, itemFunction, itemFunctionArgs, out ignoreMetadata)) {
					var sb = new StringBuilder ();
					for (int n = 0; n < transformItems.Length; n++) {
						if (n > 0)
							sb.Append (';');
						sb.Append (transformItems[n].Include);
					}	
					items = sb.ToString ();
					return true;
				}
			}

			var sbi = new StringBuilder ();

			int count = 0;
			foreach (var eit in transformItems) {
				context.SetItemContext (eit.Include, null, eit.Metadata);
				try {
					string evaluatedInclude; bool skip;
					if (itemFunction != null && ExecuteTransformIncludeItemFunction (context, eit, itemFunction, itemFunctionArgs, out evaluatedInclude, out skip)) {
						if (skip) continue;
					} else if (expression != null)
						evaluatedInclude = context.EvaluateString (expression);
					else
						evaluatedInclude = eit.Include;

					if (count++ > 0)
						sbi.Append (';');
					sbi.Append (evaluatedInclude);

				} finally {
					context.ClearItemContext ();
				}
			}
			items = sbi.ToString ();
			return true;
		}

		static IEnumerable<MSBuildItemEvaluated> ExpandWildcardFilePath (ProjectInfo pinfo, MSBuildProject project, MSBuildEvaluationContext context, MSBuildItem sourceItem, FilePath basePath, FilePath baseRecursiveDir, bool recursive, string[] filePath, int index)
		{
			var res = Enumerable.Empty<MSBuildItemEvaluated> ();

			if (index >= filePath.Length)
				return res;

			var path = filePath [index];

			if (path == "..")
				return ExpandWildcardFilePath (pinfo, project, context, sourceItem, basePath.ParentDirectory, baseRecursiveDir, recursive, filePath, index + 1);
			
			if (path == ".")
				return ExpandWildcardFilePath (pinfo, project, context, sourceItem, basePath, baseRecursiveDir, recursive, filePath, index + 1);

			if (!Directory.Exists (basePath))
				return res;

			if (path == "**") {
				// if this is the last component of the path, there isn't any file specifier, so there is no possible match
				if (index + 1 >= filePath.Length)
					return res;
				
				// If baseRecursiveDir has already been set, don't overwrite it.
				if (baseRecursiveDir.IsNullOrEmpty)
					baseRecursiveDir = basePath;
				
				return ExpandWildcardFilePath (pinfo, project, context, sourceItem, basePath, baseRecursiveDir, true, filePath, index + 1);
			}

			if (recursive) {
				// Recursive search. Try to match the remaining subpath in all subdirectories.
				foreach (var dir in Directory.GetDirectories (basePath))
					res = res.Concat (ExpandWildcardFilePath (pinfo, project, context, sourceItem, dir, baseRecursiveDir, true, filePath, index));
			}

			if (index == filePath.Length - 1) {
				// Last path component. It has to be a file specifier.
				string baseDir = basePath.ToRelative (project.BaseDirectory).ToString().Replace ('/','\\');
				if (baseDir == ".")
					baseDir = "";
				else if (!baseDir.EndsWith ("\\", StringComparison.Ordinal))
					baseDir += '\\';
				var recursiveDir = baseRecursiveDir.IsNullOrEmpty ? FilePath.Null : basePath.ToRelative (baseRecursiveDir);
				res = res.Concat (Directory.GetFiles (basePath, path).Select (f => {
					context.SetItemContext (f, recursiveDir);
					var ev = baseDir + Path.GetFileName (f);
					return CreateEvaluatedItem (context, pinfo, project, sourceItem, ev);
				}));
			}
			else {
				// Directory specifier
				// Look for matching directories.
				// The search here is non-recursive, not matter what the 'recursive' parameter says, since we are trying to match a subpath.
				// The recursive search is done below.

				if (path.IndexOfAny (wildcards) != -1) {
					foreach (var dir in Directory.GetDirectories (basePath, path))
						res = res.Concat (ExpandWildcardFilePath (pinfo, project, context, sourceItem, dir, baseRecursiveDir, false, filePath, index + 1));
				} else
					res = res.Concat (ExpandWildcardFilePath (pinfo, project, context, sourceItem, basePath.Combine (path), baseRecursiveDir, false, filePath, index + 1));
			}

			return res;
		}

		static bool ExecuteTransform (ProjectInfo project, MSBuildEvaluationContext context, MSBuildItem item, string transformExp, out List<MSBuildItemEvaluated> items)
		{
			bool ignoreMetadata = false;

			items = new List<MSBuildItemEvaluated> ();
			string itemName, expression, itemFunction; object [] itemFunctionArgs;

			// This call parses the transforms and extracts: the name of the item list to transform, the whole transform expression (or null if there isn't). If the expression can be
			// parsed as an item funciton, then it returns the function name and the list of arguments. Otherwise those parameters are null.
			if (!ParseTransformExpression (context, transformExp, out itemName, out expression, out itemFunction, out itemFunctionArgs))
				return false;

			// Get the items mathing the referenced item list
			var transformItems = project.EvaluatedItems.Where (i => i.Name == itemName).ToArray ();

			if (itemFunction != null) {
				// First of all, try to execute the function as a summary function, that is, a function that returns a single value for
				// the whole list (such as Count).
				// After that, try executing as a list transformation function: a function that changes the order or filters out items from the list.

				string result;
				if (ExecuteSummaryItemFunction (transformItems, itemFunction, itemFunctionArgs, out result)) {
					// The item function returns a value. Just create an item with that value
					var newItem = new MSBuildItemEvaluated (project.Project, item.Name, item.Include, result);
					project.EvaluatedItemsIgnoringCondition.Add (newItem);
					items.Add (newItem);
					return true;
				} else if (ExecuteTransformItemListFunction (ref transformItems, itemFunction, itemFunctionArgs, out ignoreMetadata)) {
					expression = null;
					itemFunction = null;
				}
			}

			foreach (var eit in transformItems) {
				// Some item functions cause the erasure of metadata. Take that into account now.
				context.SetItemContext (eit.Include, null, ignoreMetadata || item == null ? null : eit.Metadata);
				try {
					// If there is a function that transforms the include of the item, it needs to be applied now. Otherwise just use the transform expression
					// as include, or the transformed item include if there is no expression.

					string evaluatedInclude; bool skip;
					if (itemFunction != null && ExecuteTransformIncludeItemFunction (context, eit, itemFunction, itemFunctionArgs, out evaluatedInclude, out skip)) {
						if (skip) continue;
					} else if (expression != null)
						evaluatedInclude = context.EvaluateString (expression);
					else
						evaluatedInclude = eit.Include;

					var newItem = new MSBuildItemEvaluated (project.Project, item.Name, item.Include, evaluatedInclude);
					if (!ignoreMetadata) {
						var md = new Dictionary<string, IMSBuildPropertyEvaluated> ();
						// Add metadata from the evaluated item
						var col = (MSBuildPropertyGroupEvaluated)eit.Metadata;
						foreach (var p in col.GetRegisteredProperties ()) {
							md [p.Name] = new MSBuildPropertyEvaluated (project.Project, p.Name, p.UnevaluatedValue, p.Value);
						}
						// Now override metadata from the new item definition
						foreach (var c in item.Metadata.GetProperties ()) {
							if (string.IsNullOrEmpty (c.Condition) || SafeParseAndEvaluate (project, context, c.Condition, true))
								md [c.Name] = new MSBuildPropertyEvaluated (project.Project, c.Name, c.Value, context.EvaluateString (c.Value));
						}
						((MSBuildPropertyGroupEvaluated)newItem.Metadata).SetProperties (md);
					}
					newItem.SourceItem = item;
					newItem.Condition = item.Condition;
					items.Add (newItem);
				} finally {
					context.ClearItemContext ();
				}
			}
			return true;
		}