Passing a collection of objects from a web service

[Malcolm]

Hi. I am attempting something new in my coding and need some direction. I
have a web service that I am attempting to return a custom colleciton of
custom objects of a single type.

When I call the web method from a client host I am getting back a
1-dimensional array and I can't convert each item in the array to the
appropriate custom type that is exposed in the array.

Can any body provide me some direction on how I should be passing back a
collection of custom objects from a web service?

Any help would be appreciated.
--
Malcolm Robinson

[Peter Kelcey]

Malcom

In some cases the WSDL.exe program that generates your proxy class
follows a least-common-denominator policy when casting objects from the
returned from the webmethod. For example, an ArrayList object returned
from a webmethod would be converted to an object array in your
auto-generated proxy.

This isn't to big of an issue as once the proxy has been generated, you
can simply override the object type manually. Here's an example.

Say we were trying to generate the proxy for the following method

string DummyMethod(System.Collections.ArrayList intList)

After running the wsdl.exe, we would have the following proxy

public string DummyMethod(object[] intList) {
object[] results = this.Invoke("DummyMethod", new object[]
{
intList});
return ((string)(results[0]));
}

public System.IAsyncResult BeginDummyMethod(object[] intList,
System.AsyncCallback callback, object asyncState) {
return this.BeginInvoke("DummyMethod", new object[] {
intList}, callback, asyncState);
}
As you can see, our arraylist is now represented as an object array in
our proxy. What you have to do in this case, is modify the parameters
of the methods to use the original arraylist.

public string DummyMethod(System.Collections.ArrayList intList) {
object[] results = this.Invoke("DummyMethod", new object[]
{
intList});
return ((string)(results[0]));
}

public System.IAsyncResult
BeginDummyMethod(System.Collections.ArrayList intList,
System.AsyncCallback callback, object asyncState) {
return this.BeginInvoke("DummyMethod", new object[] {
intList}, callback, asyncState);
}

You should be able to follow this example to return your custom object
collection.

Hope that helps

Peter Kelcey

[Peter Kelcey]

Malcom

In some cases the WSDL.exe program that generates your proxy class
follows a least-common-denominator policy when casting objects from the
returned from the webmethod. For example, an ArrayList object returned
from a webmethod would be converted to an object array in your
auto-generated proxy.

This isn't to big of an issue as once the proxy has been generated, you
can simply override the object type manually. Here's an example.

Say we were trying to generate the proxy for the following method

string DummyMethod(System.Collections.ArrayList intList)

After running the wsdl.exe, we would have the following proxy

public string DummyMethod(object[] intList) {
object[] results = this.Invoke("DummyMethod", new object[]
{
intList});
return ((string)(results[0]));
}

public System.IAsyncResult BeginDummyMethod(object[] intList,
System.AsyncCallback callback, object asyncState) {
return this.BeginInvoke("DummyMethod", new object[] {
intList}, callback, asyncState);
}
As you can see, our arraylist is now represented as an object array in
our proxy. What you have to do in this case, is modify the parameters
of the methods to use the original arraylist.

public string DummyMethod(System.Collections.ArrayList intList) {
object[] results = this.Invoke("DummyMethod", new object[]
{
intList});
return ((string)(results[0]));
}

public System.IAsyncResult
BeginDummyMethod(System.Collections.ArrayList intList,
System.AsyncCallback callback, object asyncState) {
return this.BeginInvoke("DummyMethod", new object[] {
intList}, callback, asyncState);
}

You should be able to follow this example to return your custom object
collection.

Hope that helps

Peter Kelcey

[Malcolm]

Thanks Peter, I will take a look at this and see if it helps resolve my
issue. I appreciate your help.

--
Malcolm Robinson
"Peter Kelcey" wrote:

Malcom

In some cases the WSDL.exe program that generates your proxy class
follows a least-common-denominator policy when casting objects from the
returned from the webmethod. For example, an ArrayList object returned
from a webmethod would be converted to an object array in your
auto-generated proxy.

This isn't to big of an issue as once the proxy has been generated, you
can simply override the object type manually. Here's an example.

Say we were trying to generate the proxy for the following method

string DummyMethod(System.Collections.ArrayList intList)

After running the wsdl.exe, we would have the following proxy

public string DummyMethod(object[] intList) {
object[] results = this.Invoke("DummyMethod", new object[]
{
intList});
return ((string)(results[0]));
}

public System.IAsyncResult BeginDummyMethod(object[] intList,
System.AsyncCallback callback, object asyncState) {
return this.BeginInvoke("DummyMethod", new object[] {
intList}, callback, asyncState);
}
As you can see, our arraylist is now represented as an object array in
our proxy. What you have to do in this case, is modify the parameters
of the methods to use the original arraylist.

public string DummyMethod(System.Collections.ArrayList intList) {
object[] results = this.Invoke("DummyMethod", new object[]
{
intList});
return ((string)(results[0]));
}

public System.IAsyncResult
BeginDummyMethod(System.Collections.ArrayList intList,
System.AsyncCallback callback, object asyncState) {
return this.BeginInvoke("DummyMethod", new object[] {
intList}, callback, asyncState);
}

You should be able to follow this example to return your custom object
collection.

Hope that helps

Peter Kelcey