private Expression ParaseBetween(ParameterExpression parameter, UosoConditions conditions)
{
ParameterExpression p = parameter;
Expression key = Expression.Property(p, conditions.Key);
var valueArr = conditions.Value.ToString().Split(',');
if (valueArr.Length != 2)
{
throw new NotImplementedException("ParaseBetween参数错误");
}
try
{
int.Parse(valueArr[0]);
int.Parse(valueArr[1]);
}
catch
{
throw new NotImplementedException("ParaseBetween参数只能为数字");
}
Expression expression = Expression.Constant(true, typeof(bool));
//开始位置
Expression startvalue = Expression.Constant(int.Parse(valueArr[0]));
Expression start = Expression.GreaterThanOrEqual(key, Expression.Convert(startvalue, key.Type));
Expression endvalue = Expression.Constant(int.Parse(valueArr[1]));
Expression end = Expression.GreaterThanOrEqual(key, Expression.Convert(endvalue, key.Type));
return(Expression.AndAlso(start, end));
}
private Expression ParaseIn(ParameterExpression parameter, UosoConditions conditions)
{
ParameterExpression p = parameter;
Expression key = Expression.Property(p, conditions.Key);
var valueArr = conditions.Value.ToString().Split(',');
Expression expression = Expression.Constant(true, typeof(bool));
foreach (var itemVal in valueArr)
{
Expression right;
Expression value = Expression.Constant(itemVal);
if (key.Type.ToString() == "System.Int32")
{
if (itemVal == "")
{
value = Expression.Constant(-1);
}
right = Expression.Equal(key, Expression.Convert(value, key.Type));
}
else
{
right = Expression.Equal(key, Expression.Convert(value, key.Type));
}
Expression.Or(expression, right);
}
return(expression);
}
private Expression ParseCondition(UosoConditions condition)
{
ParameterExpression p = parameter;
Expression key = Expression.Property(p, condition.Key);
Expression value = Expression.Constant(condition.Value);
switch (condition.OperatorMethod)
{
case "Contains":
return(Expression.Call(key, typeof(string).GetMethod("Contains", new Type[] { typeof(string) }), value));
case "Equal":
return(Expression.Equal(key, Expression.Convert(value, key.Type)));
case "Greater":
return(Expression.GreaterThan(key, Expression.Convert(value, key.Type)));
case "GreaterEqual":
return(Expression.GreaterThanOrEqual(key, Expression.Convert(value, key.Type)));
case "Less":
return(Expression.LessThan(key, Expression.Convert(value, key.Type)));
case "LessEqual":
return(Expression.LessThanOrEqual(key, Expression.Convert(value, key.Type)));
case "NotEqual":
return(Expression.NotEqual(key, Expression.Convert(value, key.Type)));
case "In":
return(ParaseIn(p, condition));
case "Between":
return(ParaseBetween(p, condition));
default:
throw new NotImplementedException("不支持此操作");
}
}
