Android Question How do I perform type conversion?

[jarda]

Hi all

I have a library with variable declaration type android.os.Handler
How to use it in b4a?

for example.

Dim a As android.os.Handler ?!

in the library is (third-party library.jar and library.xml)

library.xml has
...........
<method>

<name>Init</name>
<returntype>void</returntype>

<parameter>

<name>context</name>
<type>android.content.Context</type>

</parameter>
<parameter>

<name>handler</name>
<type>android.os.Handler</type>

</parameter>
</method>
.............................

Dim handler As android.os.Handler

Init(context, handler )


handler should return values

SUCCESS
FAILED
CLOSED

Thanks for the advice

 

[jarda]

one more question to conversion

XML has the following definition:

<method>
<name>sendByteData</name>
<returntype>int</returntype>
<parameter>
<name>data[]</name>
<type>byte</type>
</parameter>
</method>


1. if I give in B4a

Dim data() As byte
sendByteData(data)

compiler writes :

error: inconvertible types sendByteData((byte)(_data));
required: byte
found: byte[]
1 error


---------------------
2. if I give in B4a

Dim data As byte
sendByteData(data)

compiler writes :

required: byte[]
found: byte
reason: actual argument byte cannot be converted to byte[] by method invocation conversion
1 error


Note
Erel said in ...... Basic4android byte() is identical to Java byte[]. (http://www.b4x.com/android/forum/threads/return-byte-from-external-library.15527/#content)


Does anybody know how to do it ?

 

[Erel]

It will not work. You cannot create an XML for a library that was not written specifically for B4A. You will need to create a wrapper library that calls this library.

 

[jarda]

Thank you for your answer

Applies to

android.os.Handler

or

Dim data () As Byte

 

[Erel]

It was a general statement. The byte is not problematic. According to the error message you should have passed a single byte instead of an array of bytes.

 

[jarda]

Erel,

Author library translated it using Simple Library Compiler
xml and jar file and sent me

 

[Erel]

As I wrote, it will not work. You cannot directly create a handler in B4A or a context.

If the library is not too complicated than it will be easier to access it with JavaObject.

 

[jarda]

It's all prepared for B4a

There are only two things that do not go

You have no idea how to solve it?

 

[Erel]

Ask the author to send you a java example that uses this code.

 

[jarda]

Hi Erel

code example how to call in JAVA



private TimerTask myTask = new TimerTask() {
byte[] writeData = new byte[] { 0x10, 0x04, 0x01 };
@override
public void run() {
if (mPrinter == null) {
timer.cancel();
return;
}
mPrinter.sendByteData(writeData);
if (mPrinter.read() != null) {
System.out.println("wifi connection is alive..");
} else {
errorNumber++;
if (errorNumber == 2) {
errorNumber = 0;
close();
}
}
}
};

 

[Erel]

It is missing the code that creates mPrinter.

 

[jarda]

I know, I'm waiting for the answer

 

[jarda]

Hi Erel

code in java


1. from the library

2. inside the library

 

[Erel]

This code doesn't show how myPrinter is created.

 

[jarda]

Hi Erel

I need to solve the handover byte [] data.
Only..

 

[Erel]

Based on the error this method expects a single byte, not an array of bytes.

 

[jarda]

Hi Erel

When you declare a single byte