Call Library Function in DLL

[friden]

I write a simple DLL with one function sayhello exported.
__declspec (dllexport) void SayHello(char* info, char* str)
{
strcpy(info,str);
}

Then use the CLF to call the function, when the result is correct. The str can be copied to the info in LabVIEW, but LabVIEW crashed when I close the LabVIEW.

My OS is WindowsXP + SP2, LabVIEW6i.

But I run the demo in LabVIEW7.1 all the things seem correct.

Is this is a bug of LabVIEW6i? I must write my project in LabVIEW6i. Waiting for your help, 3ks!

[rolfk]

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@friden wrote:
I write a simple DLL with one function sayhello exported.
__declspec (dllexport) void SayHello(char* info, char* str)
{
strcpy(info,str);
}

Then use the CLF to call the function, when the result is correct. The str can be copied to the info in LabVIEW, but LabVIEW crashed when I close the LabVIEW.

My OS is WindowsXP + SP2, LabVIEW6i.

But I run the demo in LabVIEW7.1 all the things seem correct.

Is this is a bug of LabVIEW6i? I must write my project in LabVIEW6i. Waiting for your help, 3ks!

---

You need to provide enough storage to the CLF for the DLL function to write the data into. This is standard C programming practice.

So initialize a string at least 1 character longer than the longest expected returned string. A simple way to do that is to use the Initialize Array function to create an array of U8 numbers and using the Numeric Array to String function convert this into a string which you wire to the left terminal for the info parameter.

Rolf Kalbermatter