计算度量值表示形式（表格）

计算度量值是每次在使用时计算其值的已命名 DAX 表达式。

计算度量值表示形式

AMO 中的计算度量值

使用 AMO 管理表格模型计算度量值时，在逻辑计算度量值对象和 Command 对象的 MdxScript 对象中定义的度量值之间存在一对一匹配关系。 每个计算度量值定义为 对象内的Command表达式CREATE MEASURE，并用分号分隔。 表格模型中的所有计算度量值对应于 MdxScript 对象中的一个命令对象中的集合 CREATE MEASURE 字符串。 对于每个计算度量值，存在与 CalculationProperty 的一对一映射关系。

下面的代码段演示如何创建计算度量值。

  
private void addCalculatedMeasure(  
                   AMO.Cube modelCube  
                 , string cmTableName  
                 , string cmName  
                 , string newCalculatedMeasureExpression  
             )  
{  
    //Verify input requirements  
    if (string.IsNullOrEmpty(cmName) || string.IsNullOrWhiteSpace(cmName))  
    {  
        MessageBox.Show(String.Format("Calculated Measure name is not defined."), "AMO to Tabular message", MessageBoxButtons.OK, MessageBoxIcon.Error);  
        return;  
    }  
    if (string.IsNullOrEmpty(newCalculatedMeasureExpression) || string.IsNullOrWhiteSpace(newCalculatedMeasureExpression))  
    {  
        MessageBox.Show(String.Format("Calculated Measure expression is not defined."), "AMO to Tabular message", MessageBoxButtons.OK, MessageBoxIcon.Error);  
        return;  
    }  
  
    StringBuilder measuresCommand = new StringBuilder();  
  
    AMO.MdxScript mdxScript = modelCube.MdxScripts["MdxScript"];  
  
    //ToDo: Verify if measure already exits and ask user what wants to do next  
  
    if (mdxScript.Commands.Count == 1)  
    {  
        measuresCommand.AppendLine("-------------------------------------------------------------");  
        measuresCommand.AppendLine("-- Tabular Model measures command (do not modify manually) --");  
        measuresCommand.AppendLine("-------------------------------------------------------------");  
        measuresCommand.AppendLine();  
        measuresCommand.AppendLine();  
        mdxScript.Commands.Add(new AMO.Command(measuresCommand.ToString()));  
  
    }  
    else  
    {  
        measuresCommand.Append(mdxScript.Commands[1].Text);  
    }  
    measuresCommand.AppendLine(string.Format("CREATE MEASURE '{0}'[{1}]={2};", cmTableName, cmName, newCalculatedMeasureExpression));  
  
    mdxScript.Commands[1].Text = measuresCommand.ToString();  
  
    if (!mdxScript.CalculationProperties.Contains(cmName))  
    {  
        AMO.CalculationProperty cp = new AMO.CalculationProperty(cmName, AMO.CalculationType.Member);  
        cp.FormatString = ""; // ToDo: Get formatting attributes for the member  
        cp.Visible = true;  
        mdxScript.CalculationProperties.Add(cp);  
    }  
  
    try  
    {  
        modelCube.Update(AMO.UpdateOptions.ExpandFull, AMO.UpdateMode.UpdateOrCreate);  
        MessageBox.Show(String.Format("Calculated Measure successfully defined."), "AMO to Tabular message", MessageBoxButtons.OK, MessageBoxIcon.Information);  
    }  
    catch (AMO.OperationException amoOpXp)  
    {  
        MessageBox.Show(String.Format("Calculated Measure expression contains syntax errors, or references undefined or missspelled elements.\nError message: {0}", amoOpXp.Message), "AMO to Tabular message", MessageBoxButtons.OK, MessageBoxIcon.Warning);  
        return;  
    }  
    catch (AMO.AmoException amoXp)  
    {  
        MessageBox.Show(String.Format("AMO exception accessing the server.\nError message: {0}", amoXp.Message), "AMO to Tabular message", MessageBoxButtons.OK, MessageBoxIcon.Warning);  
        return;  
    }  
    catch (Exception)  
    {  
        throw;  
    }  
}