START-OF-SELECTION
START-OF-SELECTION.
Effect 作用
This event keyword defines an event block whose event is triggered by the ABAP runtime environment when calling the executable program selection screen processing of a selection screen.
这个事件关键字定义了一个当调用可执行程序选择屏幕的选择屏幕处理时被ABAP运行环境触发的事件块。
In an executable program, all statements that are not declarations, and are listed before the first explicit processing block, are assigned to this event block. If the program does not contain an explicitly defined event block START-OF-SELECTION, these statements form the complete event block START-OF-SELECTION. If a program contains an explicitly defined event block START-OF-SELECTION, these statements are added to the beginning of the event block. If the program contains no explicitly defined event blocks, these statements form the entire event block START-OF-SELECTION.
在一个可执行程序中，所有的非声明语句，和被列出在第一个明确的处理块之前的语句被分配给这个事件块。如果这个程序不包含一个明确定义的事件块start-of-selection，这些语句构成了完整的事件块start-of-selection。如果一个程序包含一个明确定义的事件块start-of-selection，这些语句被附加到事件块的开始。如果程序没有包含明确定义的事件块，这些语句构成整个事件块START-OF-SELECTION.
Note 注
If the program is linked to a logical database, preparations can be made here before the logical database reads data. If the program is not linked to a logical database, this event block even displays a "main program" from which procedures or screen layouts are called.
如果程序和一个逻辑数据库相关联，在逻辑数据库读取数据之前可以在这做些准备工作。如果程序没有相关联的逻辑数据库，这个事件块相当于显示了一个"main program"从这里调用过程或者屏幕布局。
Example 例子
Note the following three programs, each with the same function.
注意下面的三个程序，每一个具有相同的函数。
The first program contains an explicit event block START-OF-SELECTION and shows the recommended spelling.
第一个程序包含一个明确的事件块START-OF-SELECTION 并且显示了建议写法。
REPORT test_start_of_selection.
DATA text TYPE string.
START-OF-SELECTION.
text = `Hello World!`.
WRITE text.
In the second program, there is an assignment before the first processing block, which is inserted in the event block START-OF-SELECTION.
在第二个程序中，在第一个处理块之前有一个作业，它被插入到事件块START-OF-SELECTION中。
REPORT test_start_of_selection.
DATA text TYPE string.
text = `Hello World!`.
START-OF-SELECTION.
WRITE text.
In the third program, there is no explicit processing block. All statements form the event block START-OF-SELECTION.
在第三个程序中，没有明确的处理块。所有的语句构成了事件块START-OF-SELECTION。
REPORT test_start_of_selection.
DATA text TYPE string.
text = `Hello World!`.
WRITE text.
Example 例子
see Example for Reporting Events. 参见Reporting Events的例子。
