CustomPaperSource重置并给出nullreferece

问题描述

Hi

打印CrystalReport时，CustomPaperSource有时会重置为null。
只有在RawKind设置为giro（包含
"261"，我的打印机上的纸张源代码）之后才会出现问题，而且只有一次在。


示例代码：

System.Drawing.Printing.PaperSource source
= new System.Drawing.Printing.PaperSource（）;
int farge = 259，giro = 260，vanlig = 261;

rdReport.PrintOptions.CustomPaperSource = source;

if（printoptions ==" farge"）

rdReport.PrintOptions.CustomPaperSource.RawKind = farge;
else if（printoptions ==" giro"）
rdReport.PrintOptions.CustomPaperSource.RawKind = giro;


rdReport.PrintOptions.CustomPaperSource.RawKind = vanlig;

if（null == rdReport.PrintOptions.CustomPaperSource）
Console.WriteLine（" Err！"）;

frmMain.WriteLog（" now printing" + sFilename）;
frmMain .WriteLog（" printoptions设置为" +
rdReport.PrintOptions.CustomPaperSource.RawKind.ToString（））;


在最后一行我_sometimes_得到一个NullReferenceException。我告诉垃圾收集不要碰到物体。没有帮助。

最后一个"if"不会触发。所以看起来像CustomPaperSource被重置






































你必须使用

System.Drawing.Printing 。 PaperSourceKind。

如果您知道纸张来源的名称，请使用paperSource prperty

查看floowing链接

http://technicalsupport.businessobjects.com/KanisaSupportSite/search.do?cmd=displayKC& DOCTYPE = KC&安培;外部ID = c2014922&安培; sliceId =安培; dialogID = 7202396&安培; STATEID = 1％200％207200708

Hi

When printing a CrystalReport CustomPaperSource is sometimes reset to null.
the problem only occures after RawKind has been set to giro (which contains
"261", the code for a paper source on my printer), and only once in a
while.


Sample code:

System.Drawing.Printing.PaperSource source
        = new System.Drawing.Printing.PaperSource();
int farge = 259, giro = 260, vanlig = 261;

rdReport.PrintOptions.CustomPaperSource = source;
           
if (printoptions == "farge")
        rdReport.PrintOptions.CustomPaperSource.RawKind = farge;
else if (printoptions == "giro")
        rdReport.PrintOptions.CustomPaperSource.RawKind = giro;
else
        rdReport.PrintOptions.CustomPaperSource.RawKind = vanlig;

if (null == rdReport.PrintOptions.CustomPaperSource)
        Console.WriteLine("Err!");

frmMain.WriteLog("now printing " + sFilename);
frmMain.WriteLog("printoptions set to " +
rdReport.PrintOptions.CustomPaperSource.RawKind.ToString());


at the last line i _sometimes_ get a NullReferenceException. i've told
garbage collection not to touch the object. didn't help.

the last "if" does not trigger. so it seems like CustomPaperSource is reset
when read.


-L

解决方案

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