/// <summary>
/// 执行表达式
/// </summary>
/// <param name="context">上下文对象</param>
/// <returns>运算结果</returns>
public object Eval(IDCExpressionContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
if (this._RootItem == null)
{
throw new NullReferenceException("this.RootItem");
}
object result = this._RootItem.Eval(context);
if (result is Array)
{
Array arr = (Array)result;
if (arr.Length > 0)
{
return(arr.GetValue(0));
}
else
{
return(null);
}
}
return(result);
}
/// <summary>
/// 执行表达式
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public override object Eval(IDCExpressionContext context)
{
if (this.Items != null && this.Items.Count > 0)
{
return(this.Items[0].Eval(context));
}
return(null);
}
private string GetStringValue(DCExpressionItem item, IDCExpressionContext context)
{
if (item == null)
{
return(null);
}
object v = item.Eval(context);
return(DCExpression.ToString(v));
}
private bool GetBooleanValue(DCExpressionItem item, IDCExpressionContext context, bool defaultValue = false)
{
if (item == null)
{
return(defaultValue);
}
object v = item.Eval(context);
return(DCExpression.ToBoolean(v));
}
private double GetDoubleValue(DCExpressionItem item, IDCExpressionContext context, double defaultValue = 0)
{
if (item == null)
{
return(defaultValue);
}
object v = item.Eval(context);
return(DCExpression.ToDouble(v, defaultValue));
}
/// <summary>
/// 执行表达式
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public override object Eval(IDCExpressionContext context)
{
object[] pvs = null;
if (_Parameters != null && _Parameters.Count > 0)
{
pvs = new object[this._Parameters.Count];
for (int iCount = 0; iCount < this._Parameters.Count; iCount++)
{
pvs[iCount] = this._Parameters[iCount].Eval(context);
}
}
object result = context.ExecuteFunction(this.Name, pvs);
return(result);
}
/// <summary>
/// 执行表达式
/// </summary>
/// <param name="context">上下文对象</param>
/// <returns>执行结果</returns>
public override object Eval(IDCExpressionContext context)
{
if (this.ValueType == DCValueType.String)
{
return(this._StringValue);
}
if (this.ValueType == DCValueType.Number)
{
return(this._NumberValue);
}
if (this.ValueType == DCValueType.Boolean)
{
return(this._BooleanValue);
}
throw new NotSupportedException(this.ValueType.ToString());
}
/// <summary>
/// 执行表达式
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public virtual object Eval(IDCExpressionContext context)
{
return(null);
}
/// <summary>
/// 获得数值比较结果
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
private int GetEqualResult(IDCExpressionContext context)
{
object v1 = this.Left == null ? null : this.Left.Eval(context);
object v2 = this.Rigth == null ? null : this.Rigth.Eval(context);
if (v1 == v2)
{
return(0);
}
if ((v1 is int || v1 is double) && (v2 is int || v2 is double))
{
// 明确进行数字比较
double d1 = Convert.ToDouble(v1);
double d2 = Convert.ToDouble(v2);
return(d1.CompareTo(d2));
}
if (v1 is string && v2 is string)
{
// 明确进行字符串比较
return(string.Compare((string)v1, (string)v2));
}
if (v1 is float && v2 is float)
{
return(((float)v1).CompareTo((float)v2));
}
if (v1 is double && v2 is double)
{
return(((double)v1).CompareTo((double)v2));
}
bool hasContent1 = v1 != null && DBNull.Value.Equals(v1) == false;
bool hasContent2 = v2 != null && DBNull.Value.Equals(v2) == false;
if (hasContent1 && hasContent2)
{
try
{
// 两个数据都不为空
var t1 = v1.GetType();
var t2 = v2.GetType();
if (t1 == t2)
{
// 类型一致，则进行比较
return(System.Collections.Comparer.Default.Compare(v1, v2));
}
// 类型不一样,则设置标准数据类型
var targetVT = (DCValueType)Math.Min((int)GetValueType(t1), (int)GetValueType(t2));
if (targetVT == DCValueType.Boolean)
{
bool b1 = Convert.ToBoolean(v1);
bool b2 = Convert.ToBoolean(v2);
return(b1.CompareTo(b2));
}
else if (targetVT == DCValueType.Number)
{
double dbl1 = Convert.ToDouble(v1);
double dbl2 = Convert.ToDouble(v2);
return(dbl1.CompareTo(dbl2));
}
else
{
string str1 = Convert.ToString(v1);
string str2 = Convert.ToString(v2);
return(str1.CompareTo(str2));
}
}
catch (System.Exception ext)
{
System.Diagnostics.Debug.WriteLine(ext.ToString());
}
}
return(hasContent1.CompareTo(hasContent2));
}
/// <summary>
/// 执行表达式
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public override object Eval(IDCExpressionContext context)
{
switch (this.Operator)
{
#region 逻辑运算
case DCOperatorType.And:
{
//逻辑与
bool v1 = GetBooleanValue(this.Left, context, false);
if (v1 == false)
{
return(false);
}
bool v2 = GetBooleanValue(this.Rigth, context, false);
return(v2);
}
case DCOperatorType.Or:
{
//逻辑或
bool v1 = GetBooleanValue(this.Left, context, false);
if (v1)
{
return(true);
}
bool v2 = GetBooleanValue(this.Rigth, context, false);
return(v2);
//return v1 && v2;
}
#endregion
#region 数值比较
case DCOperatorType.Bigger:
{
// 大于
return(GetEqualResult(context) > 0);
}
case DCOperatorType.BiggerOrEqual:
{
// 大于等于
return(GetEqualResult(context) >= 0);
}
case DCOperatorType.Equal:
{
// 等于
return(GetEqualResult(context) == 0);
}
case DCOperatorType.Less:
{
// 大于等于
return(GetEqualResult(context) < 0);
}
case DCOperatorType.LessOrEqual:
{
// 大于等于
return(GetEqualResult(context) <= 0);
}
case DCOperatorType.Unequal:
{
// 不等于
return(GetEqualResult(context) != 0);
}
#endregion
#region 数学运算
case DCOperatorType.Plus:
{
// 加法
double v1 = GetDoubleValue(this.Left, context, 0);
double v2 = GetDoubleValue(this.Rigth, context, 0);
return(v1 + v2);
}
case DCOperatorType.Minus:
{
// 减法
double v1 = GetDoubleValue(this.Left, context, 0);
double v2 = GetDoubleValue(this.Rigth, context, 0);
return(v1 - v2);
}
case DCOperatorType.Multi:
{
// 乘法
double v1 = GetDoubleValue(this.Left, context, 0);
double v2 = GetDoubleValue(this.Rigth, context, 0);
return(v1 * v2);
}
case DCOperatorType.Negative:
{
// 负数
double v1 = 0;
if (this.Rigth != null)
{
v1 = GetDoubleValue(this.Rigth, context, 0);
}
else if (this.Left != null)
{
v1 = GetDoubleValue(this.Left, context, 0);
}
return(-v1);
}
case DCOperatorType.Division:
{
// 除法
double v1 = GetDoubleValue(this.Left, context, 0);
double v2 = GetDoubleValue(this.Rigth, context, 0);
if (v2 == 0)
{
return(double.NaN);
}
else
{
return(v1 / v2);
}
}
case DCOperatorType.Mod:
{
// 求模
double v1 = GetDoubleValue(this.Left, context, 0);
double v2 = GetDoubleValue(this.Rigth, context, 0);
if (v2 == 0)
{
return(double.NaN);
}
else
{
return(v1 % v2);
}
}
#endregion
default:
throw new NotSupportedException(this.Operator.ToString());
}
}
/// <summary>
/// 执行表达式，根据上下文获取变量值
/// </summary>
/// <param name="context">上下文对象</param>
/// <returns>变量值</returns>
public override object Eval(IDCExpressionContext context)
{
return(context.GetVariableValue(this.Name));
}