Mercurial > pub > bltoolkit
view Source/Data/Linq/Builder/CastBuilder.cs @ 0:f990fcb411a9
Копия текущей версии из github
author | cin |
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date | Thu, 27 Mar 2014 21:46:09 +0400 |
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using System; using System.Data; using System.Linq.Expressions; namespace BLToolkit.Data.Linq.Builder { using BLToolkit.Linq; class CastBuilder : MethodCallBuilder { protected override bool CanBuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo) { return methodCall.IsQueryable("Cast"); } protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo) { var sequence = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0])); return new CastContext(sequence, methodCall); } protected override SequenceConvertInfo Convert( ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo, ParameterExpression param) { return null; } class CastContext : PassThroughContext { public CastContext(IBuildContext context, MethodCallExpression methodCall) : base(context) { _methodCall = methodCall; } private readonly MethodCallExpression _methodCall; public override void BuildQuery<T>(Query<T> query, ParameterExpression queryParameter) { var expr = BuildExpression(null, 0); var mapper = Builder.BuildMapper<T>(expr); query.SetQuery(mapper.Compile()); } public override Expression BuildExpression(Expression expression, int level) { var expr = base.BuildExpression(expression, level); var type = _methodCall.Method.GetGenericArguments()[0]; if (expr.Type != type) expr = Expression.Convert(expr, type); return expr; } } } }