Tuesday, September 7, 2010

Android: 2 view elements side by side

In my Android application, I wanted to display 2 spinners, side by side (50% of the width each).
I didn't want to use width = "100px" for example. I wanted to be relative as much as possible.
So here is what I did:

android:layout_alignParentBottom="true" android:layout_width="fill_parent">
android:layout_height="wrap_content" android:weightSum="100">



***WARNING*** XML tags are case sensitive. In my example above, I don't know why it's display in lower case... Please use TableLayout, TableRow and Button!

I created a tableLayout with 1 tablerow. In each tablerow I added 2 buttons.
I set the attribute weightsum="100" to the row. And for each element of the row,I set layout_weight="50".
And that's it!

Friday, June 11, 2010

ruby - windows7 - mysql

So I tried to install Ruby on Rails on my windows 7, but it was strange...
First, I followed this tutorial -­> http://rubyonrails.org/download

1) I installed Ruby on my C:\
2) I installed Gem on my C:\
3) I did gem install rails, but it says it needed other gem (activesupport, rack....)
Strange... So I downloaded each missing gem and did gem install rack-1.0.0.gem
Then I could install rails!
4) I installed mySQL and NetBeans.

but impossible to create table (db:migrate), and suddenly I have a blue screen...

In fact there was 2 problems.
1) The drive C:\ is kind of protected for writing (Vista & 7). I uninstalled Ruby and installed it on D:\.
After that, when I did gem install rails, it worked like a charm.

2) I couldn't create tables because mySQL5.1 doesn't like Ruby very well. So you should download a latest library. For more information, please see -­> http://forums.aptana.com/viewtopic.php?f=20&t=7563&p=27407&hilit=libmysql.dll#p27407

And that's it!

Saturday, April 17, 2010

VB .net avec win7 x64

So here is one thing that may help other people.
I have Win7 x64 and a VB application using Microsoft Access DB. My version of Office is 2007 32 bits.
The VB application is old, and I have to make it works on VS2008. Before it used OLEDB4.0. When I started the program I had this error: provider is not registered on locale machine.

After searching on the Web, I found out that I needed to install new driver (or provider) from Microsoft Website: 2010 Office System Driver Beta: Data Connectivity Components.

And here is what I understood:
  • download 14.0.4536.1000_AccessDatabaseEngine_none_ship_x86_en-us_exe\AccessDatabaseEngine.exe if your Office is 32bits.
  • in the properties of your VB application, go to advanced compile options and choose CPU target: x86
  • in the string connection, use: gDB.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=""MDITMain.mdb"";Persist Security Info=False". Do not use "14.0". This is a bug, you can find more information on google

If you want to test your DB connection, check here: "UDL Test" on a 64 bit machine
Here is what was inside my UDL file:
; Everything after this line is an OLE DB initstring
Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\xxx\Documents\Visual Studio 2008\Projects\WindowsApplication1\WindowsApplication1\DBMain.mdb;Persist Security Info=False

That's it for now

Friday, March 26, 2010

Android join tables

In my application, I have many tables and for a reason, I had to do a query using "join".
I'll not explain how to access a database, but just so you know, check on Google for
object SQLiteDatabase.

So I was checking at the method query , here is the information:

public Cursor query (String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy)

table :The table name to compile the query against.

For example:

Cursor cursor = myDataBase.query(
"myTableA" ,
new String[] { "_id", "name"},
null,null, null, null, null);

That's nice, but what if I want to a "join" ? I need more than 1 table in my query.
Well, at beginning I found CursorJoiner. Nice, I can join 2 cursors. But what if I have 3 or more joins to do ??

In fact, the parameter "table " (function query) can contains many tables (not just one).
For example:

Cursor cursor = myDataBase.query(
"myTableA a, myTableB b",
new String[] { "a._id", "a.name", "b._id", "b.name"},
"a.foreignKey = b._id",
null, null, null, null);

That was not difficult, but the definition of the parameter "table " was not so good.

Another solution would be to use SQLiteQueryBuilder.

SQLiteQueryBuilder myQuery = new SQLiteQueryBuilder();
myQuery.setTables("myTableA, myTableB");
myQuery.appendWhere("a.FK = b._id");
Cursor cursor = myQuery.query(myDataBase, null, null, null, null, null, null);

Tuesday, March 16, 2010

Android: add xml layout dynamically

For the application I'm creating, the user can use "search" function. This function will return a list of castles.
Here is the XML to display one result (/res/layout/element_result.xml). There is 1 button, 2 text fields and 1 image :





Then, I created a XML layout (/res/layout/results.xml) who will contain the list of results. That means, there will be many times element_result.xml inside results.xml. There is a scrollView and a table layout.



Ok, our views are ready. Now how to use them in Java. I read this blog, and that helps me a lot : Android LayoutWidth being disregarded by cascaded use of LayoutInflater.

Here is my activity file:

public class ResultActivity extends Activity{

public void onCreate(Bundle savedInstanceState) {
// "results" is for the xml file "results.xml"


public void addElementResult() {
// "myTableLayout" is the id of the element in results.xml
TableLayout tl = (TableLayout)findViewById(R.id.myTableLayout);
// we will use service from inflater
LayoutInflater inflater = (LayoutInflater)getSystemService(LAYOUT_INFLATER_SERVICE);

//doing a loop to add many times the same xml
for(int i = 0; i < 17; i++) {
// "element_result" is the name of the xml file "element_result.xml".
// Create the itemView who will be added.
// itemView = element_result.xml
View itemView = inflater.inflate(R.layout.element_result, null);
// get the textView, and set the text to something
TextView t1 = (TextView) itemView.findViewById(R.id.presentation);
t1.setText("something" + i);

TextView t2 = (TextView) itemView.findViewById(R.id.description);
t2.setText("oh oh oh" + i);

//add the itemView
tl.addView(itemView, new TableLayout.LayoutParams(

So the result will look like that :

Note: in results.xml, I created a scrollView because if there is 20 results, the user should be able to scroll down to see all the results.
Note: I used "tableLayout" to be able to add results one under another one.

Wednesday, March 10, 2010

Android: main.out.xml error

So it's been long time, I'm not doing Ruby anymore.
Now, for myself, I decided to create an Android application. At first, I wanted to create an Iphone application, but only people having a Mac can use the SDK... So let's use the Android SDK!
After doing the tutorial Hello World (see here), I started doing my application. And after a few minutes I had an error...

[2010-03-09 11:32:04 - shiro]Error in an XML file: aborting build.
[2010-03-09 11:32:05 - shiro]res\layout\main.xml:0: error: Resource entry main is already defined.
[2010-03-09 11:32:05 - shiro]res\layout\main.out.xml:0: Originally defined here.
[2010-03-09 11:32:05 - shiro]D:\workspace\shiro\res\layout\main.out.xml:1: error: Error parsing XML: no element found

For information, I'm using Eclipse. Why when I click on "run" I have this error ? Why Eclipse is creating a new file "main.out.xml" and then complain about it ? My application is really small, I didn't write any line of code in my main activity...

Well the error is simple, and it's not related to the application directly. It's a problem with Eclipse. To run the application, I must select the project (root folder) in the left column and then I can click on "run".

I had this error, because I was running the "main.xml". So Eclipse could not do anything with that.
Here is a noobie error, but it was difficult to find the solution...
I guess the next post will also concern Android application. It's always fun to discover new things :)