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function - 为什么返回值总是空字符串？

问题描述

我的 PowerBuilder 函数在某些条件下返回硬编码字符串值。

我检查了调试器，其中一个条件肯定会发回硬编码字符串，但在调用函数的一侧，我总是得到空字符串“”。

这个 PowerBuilder 技巧对我来说是新的，我无法确定该函数是否有问题或调用该函数的脚本。

请查看函数的代码并帮助我摆脱这些 PowerBuilder 沟渠。:(

问候，

/// Function Name: _wichTransObject
/// Parameters: Gets Datawindow control
/// Return: String name of the transaction object to use.
/// Purpose: when image is there in nested reports or the directly blob column is used in datawindow object,
/// only native connection can display images while ODBC fails. This function was written to select proper 
/// transaction object so images are displayed in reports.

String dwSyntax, dwo, OriginalDwo
Long RptAt, RptDwoAt, BlobAt

dw_1.SetRedraw(FALSE)
OriginalDwo = dw_1.DataObject

dwSyntax = dw_1.Describe("datawindow.syntax");

/// Nested Reports may have images in them. That can be checked 
/// find the report and if exist then pick its dwo and repeat same steps again for more reports
RptAt = Pos(dwSyntax, "report(", 1)
DO WHILE RptAt > 0
    RptDwoAt = 0
    RptDwoAt = Pos(dwSyntax, "dataobject=", RptAt) /// Get the dataobject of current report
    IF RptDwoAt > 0 THEN
        /// set the dataobject to dw_1 and explore it further
        dwo = Mid(dwSyntax, RptDwoAt + 12, Pos(dwSyntax, "~"", RptDwoAt + 12)  - ( RptDwoAt + 12 ))
        dw_1.DataObject = dwo

        /// explore the nested dataobject and look for blob column
        dwSyntax = dw_1.Describe("datawindow.syntax");
        BlobAt = Pos(dwSyntax, "keyclause", 1) 
        IF BlobAt > 0 THEN /// if blob exist then return NATCA
            dw_1.DataObject = OriginalDwo
            dw_1.SetRedraw(TRUE)
            Return "NATCA"
        END IF
    END IF
LOOP

/// find the report and if exist then pick its dwo and repeat same steps again for more reports
BlobAt = Pos(dwSyntax, "keyclause", 1)
IF BlobAt > 0 THEN
    dw_1.DataObject = OriginalDwo
    dw_1.SetRedraw(TRUE)
    Return "NATCA"
ELSE
    dw_1.DataObject = OriginalDwo
    dw_1.SetRedraw(TRUE)
    Return "SQLCA"  
END IF

/// 以下是调用上述函数的代码

String WTO

WTO = _WhichTransObject(dw_pb_report)
IF WTO = "NATCA" THEN
    /// Make a native connection
    dw_1.SetTransObject(NATCA)
ELSE
    /// Go away with ODBC
    dw_1.SetTransObject(SQLCA)
END IF

标签： functionreturnpowerbuildernothing

解决方案

重命名函数解决了这个问题。

对于我总是以下划线开头的事件，这从来都不是问题。但是，我猜测在不知道确切原因的情况下更改函数名称。

WTO = oayoay_whichtransobject(dw_pb_report)从函数中获取正确的返回值。那是一个全球性的功能。

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