知识点：
（1）按情况转移选择
SELECT...ENDSEL，块根据一个或多个CASE测试结果执行语句。SELECT块以SELECT语句开始，用一个可选的DFTCAS块语句包含的多个CASE块，并以ENDSEL语句终止。
（2）情况语句
CASE...ENDCAS根据SELECT参数进行的测试结果，执行界定在CASE和ENDCAS语句之间的语句。
（3）默认情况语句
仅当没有任何一个CASE子句在SELECT块中被激活时，DETCAS...ENDCAS块执行界定在DFTCAS和ENDCAS语句之间的语句。
第一个CASE语句后面的语句块，其文字参数等于SELECT语句参数的值，将一直执行，直到遇到ENDCAS语句，然后程序执行将在ENDSEL语句后的第一个语句处继续执行。如果没有CASE语句的文字参数等于SELECT参数，并且如果存在可选的DFTCAS，则执行DFTCAS语句和ENDCAS语句之间的语句。ENDSEL语句指定SELECT ... ENDSEL块的结尾。
为了确定相等性，CASE语句的文字参数必须与SELECT语句的参数具有相同的数据类型。如果论点不同，则它们不相等。如果两个参数都是字符串，则字符串必须具有相同的长度并包含相同的区分大小写的字符，它们的顺序相同。如果两个参数都是整数，则它们必须是相同的数字才能相等。
SELECT ... ENDSEL块的功能如下。作为参数传递给SELECT语句的表达式将被计算一次，以确定整数或字符串。这个整数或字符串依次与每个CASE语句的文字参数进行比较。如果发现CASE和SELECT语句参数相等，则在CASE语句之后执行所有语句，直到遇到ENDCAS语句，此时将执行传递给ENDSEL语句之后的语句。在成功进行相等性评估后执行语句时，如果在ENDCAS语句之前遇到另一个CASE语句，则忽略CASE语句并继续执行，直到遇到ENDCAS语句。如果存在DFTCAS语句且SELECT参数与任何CASE参数之间未找到相等性，则执行DFTCAS语句之后的语句，直到遇到ENDCAS语句，此时将执行传递给ENDSEL语句之后的语句。如果DFTCAS语句不存在且SELECT参数与任何CASE参数之间没有找到相等性，那么SELECT ... ENDSEL块中的语句不会被执行。
SELECT..ENDSEL块中CASE语句的数量没有限制。
SELECT ... ENDSEL块中只能有一个DFTCAS语句
RationalDMIS高级指令（按情况转移选择 SELECT CASE）
DMIS5.2标准示例
RationalDMIS实际案例：
1.分支选择 SELECT CASE
DECL/INTGR,i
DECL/CHAR,50,tx
i=ASSIGN/10
SELECT/i
CASE/10
tx=ASSIGN/CONCAT('THE ACTUAL VALUE OF X IS: ',STR(i))
TEXT/OPER,tx
ENDCAS
CASE/20
tx=ASSIGN/CONCAT('THE ACTUAL VALUE OF X IS: ',STR(i))
TEXT/OPER,tx
ENDCAS
DFTCAS
TEXT/OPER,'X is not equal to the 2 cases'
ENDCAS
ENDSEL
2.分支选择 测量圆孔
MODE/AUTO,PROG,MAN
DECL/COMMON, INTGR, KNPTN1
NAN = PROMPT/TITLE,'请输入要测量圆孔号',EDIT,KNPTN1
SELECT/KNPTN1
CASE/1
F(CIR1)=FEAT/CIRCLE,INNER,CART,0.0000,-0.0000,-4.2875,0.0000,0.0000,1.0000, 68.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR1), 5
ENDMES
ENDCAS
CASE/2
F(CIR2)=FEAT/CIRCLE,INNER,CART,55.0000,5.0000,-17.8453,0.0000,0.0000,1.0000, 8.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR2), 5
ENDMES
ENDCAS
CASE/3
F(CIR3)=FEAT/CIRCLE,INNER,CART,90.0000,-0.0000,-37.9710,0.0000,0.0000,1.0000, 8.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR3), 5
ENDMES
ENDCAS
CASE/4
F(CIR4)=FEAT/CIRCLE,INNER,CART,-33.0000,-38.0000,-3.1978,0.0000,0.0000,1.0000, 20.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR4), 5
ENDMES
ENDCAS
ENDSEL
3.选择测量圆孔（提示组功能） 字符
MODE/AUTO,PROG,MAN
DECL/COMMON,CHAR,255,C1
KNPTN1=PROMPT/GROUP,'请输入测量圆孔号',C1,'圆孔1','圆孔2','圆孔3','圆孔4'
SELECT/C1
CASE/'圆孔1'
F(CIR1)=FEAT/CIRCLE,INNER,CART,0.0000,-0.0000,-4.2875,0.0000,0.0000,1.0000, 68.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR1), 5
ENDMES
ENDCAS
CASE/'圆孔2'
F(CIR2)=FEAT/CIRCLE,INNER,CART,55.0000,5.0000,-17.8453,0.0000,0.0000,1.0000, 8.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR2), 5
ENDMES
ENDCAS
CASE/'圆孔3'
F(CIR3)=FEAT/CIRCLE,INNER,CART,90.0000,-0.0000,-37.9710,0.0000,0.0000,1.0000, 8.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR3), 5
ENDMES
ENDCAS
CASE/'圆孔4'
F(CIR4)=FEAT/CIRCLE,INNER,CART,-33.0000,-38.0000,-3.1978,0.0000,0.0000,1.0000, 20.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR4), 5
ENDMES
ENDCAS
ENDSEL
4.选择测量圆孔（提示组功能） 整型变量
MODE/AUTO,PROG,MAN
DECL/COMMON, INTGR, KNPTN2
KNPTN1=PROMPT/GROUP,'请输入测量圆孔号',KNPTN2,'圆孔1','圆孔2','圆孔3','圆孔4'
SELECT/KNPTN2
CASE/1
F(CIR1)=FEAT/CIRCLE,INNER,CART,0.0000,-0.0000,-4.2875,0.0000,0.0000,1.0000, 68.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR1), 5
ENDMES
ENDCAS
CASE/2
F(CIR2)=FEAT/CIRCLE,INNER,CART,55.0000,5.0000,-17.8453,0.0000,0.0000,1.0000, 8.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR2), 5
ENDMES
ENDCAS
CASE/3
F(CIR3)=FEAT/CIRCLE,INNER,CART,90.0000,-0.0000,-37.9710,0.0000,0.0000,1.0000, 8.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR3), 5
ENDMES
ENDCAS
CASE/4
F(CIR4)=FEAT/CIRCLE,INNER,CART,-33.0000,-38.0000,-3.1978,0.0000,0.0000,1.0000, 20.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR4), 5
ENDMES
ENDCAS
ENDSEL
5.请输入要测量的圆孔号
MODE/AUTO,PROG,MAN
DECL/COMMON,CHAR,255,C1
KNPTN1 = PROMPT/TITLE,'请输入要测量的圆孔号',EDIT,C1
SELECT/C1
CASE/'CIR1'
F(CIR1)=FEAT/CIRCLE,INNER,CART,0.0000,-0.0000,-4.2875,0.0000,0.0000,1.0000, 68.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR1), 5
ENDMES
ENDCAS
CASE/'CIR2'
F(CIR2)=FEAT/CIRCLE,INNER,CART,55.0000,5.0000,-17.8453,0.0000,0.0000,1.0000, 8.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR2), 5
ENDMES
ENDCAS
CASE/'CIR3'
F(CIR3)=FEAT/CIRCLE,INNER,CART,90.0000,-0.0000,-37.9710,0.0000,0.0000,1.0000, 8.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR3), 5
ENDMES
ENDCAS
CASE/'CIR4'
F(CIR4)=FEAT/CIRCLE,INNER,CART,-33.0000,-38.0000,-3.1978,0.0000,0.0000,1.0000, 20.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR4), 5
ENDMES
ENDCAS
ENDSEL
6.分支语句的作用及其应用
DECL/COMMON,CHAR,20,AAA
TEMPCHAR = PROMPT/TEXT,'你是怎么笑的',LIST,AAA,'哈哈','嘿嘿','呵呵','HOHO'
SELECT/AAA
CASE/'哈哈'
WRITE/DID(DEFAULTSCREEN),'性格爽朗'
ENDCAS
CASE/'嘿嘿'
WRITE/DID(DEFAULTSCREEN),'阴险~~~'
ENDCAS
CASE/'呵呵'
WRITE/DID(DEFAULTSCREEN),'没心没肺~~'
ENDCAS
CASE/'HOHO'
WRITE/DID(DEFAULTSCREEN),'上网上多了吧'
ENDCAS
ENDSEL
7.分支选择——列表选择
