Free Code Snippets: January 2012

Monday, January 23, 2012

Display an Alert Dialog

[sourcecode language="java"]
package com.my.option;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class OptionMenuActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

Button b = (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
AlertDialog.Builder builder = new AlertDialog.Builder(OptionMenuActivity.this);
builder.setMessage("Do you really need to exit?");
builder.setCancelable(false);

builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface arg0, int arg1) {
OptionMenuActivity.this.finish();

}
});

builder.setNegativeButton("No", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int arg1) {
dialog.cancel();

}

});

AlertDialog alert = builder.create();
alert.show();
}
});
}

}

[/sourcecode]

How to add a context menu in Android

Create an Android XML file of Menu type

Add menu options as you preferred. Each menu option should be indicated as <item> XML element.

This is my context_menu.xml file.[sourcecode language="xml"]
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<item android:id="@+id/item1" android:title="option1"></item>
<item android:id="@+id/item2" android:title="option2"></item>
</menu>
[/sourcecode]

Override onCreateContextMenu and onContextItemSelected in your Activity.java file
Add a button in main.xml to respond our context menu.
[sourcecode language="java"]
package com.my.option;

import java.util.zip.Inflater;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.Button;

public class ContextMenuActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

Button b = (Button) findViewById(R.id.button1);
registerForContextMenu(b);
}

@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {

MenuInflater inflator = getMenuInflater();
inflator.inflate(R.menu.context_menu, menu);

}

@Override
public boolean onContextItemSelected(MenuItem item) {
if(item.getItemId() == R.id.item1)
Log.d("Edit", "Selected : Edit Option");
if(item.getItemId() == R.id.item2)
Log.d("Delete", "Selected : Delete Option");
return super.onContextItemSelected(item);
}
}
[/sourcecode]

Simple Options Menu in Android

Create an Android XML file of Menu type

Add menu options as you preferred. Each menu option should be indicated as <item> XML element.

This is my options.xml file.[sourcecode language="xml"]
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >

<item android:id="@+id/item1" android:title="Edit" android:icon="@android:drawable/ic_menu_edit"></item>
<item android:id="@+id/item2" android:title="Delete" android:icon="@android:drawable/ic_menu_delete"></item>
<item android:id="@+id/item3" android:title="Help" android:icon="@android:drawable/ic_menu_help"></item>
<item android:id="@+id/item4" android:title="More" android:icon="@android:drawable/ic_menu_more"></item>

</menu>
[/sourcecode]

My options menu is not just text-based. Each menu item is displayed with a relevant icon. Here I used the icons found in the Android.jar file of my project. You can find such icons using this path
<app root > --> Android <Your Android platform> --> android.jar --> res --> drawable-hdpi(icons for menu prefixed with ic_menu)

Override onCreateOptionsMenu and onOptionsItemSelected in your Activity.java file
[sourcecode language="java"]
package com.my.option;

import java.io.Console;
import java.util.zip.Inflater;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;

public class OptionMenuActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflator = getMenuInflater();
inflator.inflate(R.menu.options, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
if(item.getItemId() == R.id.item1)
Log.d("Edit", "Selected : Edit Option");
if(item.getItemId() == R.id.item2)
Log.d("Delete", "Selected : Delete Option");
return super.onOptionsItemSelected(item);
}
}
[/sourcecode]

Saturday, January 7, 2012

Write Data in XML File Using C#

Sample XML File

[sourcecode language="xml"]
<?xml version="1.0" encoding="utf-8"?>

<DoctorInfo>

 

<Doctor>

<id>01</id>

<name>Ranil Jayaweera</name>

<speciality>GI</speciality>

</Doctor>

 

<Doctor>

<id>02</id>

<name>Aruna Gunathilaka</name>

<speciality>VP</speciality>

</Doctor>

 

<Doctor>

<id>03</id>

<name>Jaya Palipana</name>

<speciality>VOG</speciality>

</Doctor>

 

</DoctorInfo>
[/sourcecode]

The Code

[sourcecode language="csharp"]
XmlDocument xmlDoc = new XmlDocument();

xmlDoc.Load(Application.StartupPath + "\\DoctorsList.xml");

XmlElement subroot = xmlDoc.CreateElement("Doctor");

 

XmlElement childElementId = xmlDoc.CreateElement("id");

XmlText xmlTextId = xmlDoc.CreateTextNode(txtid.Text);

childElementId.AppendChild(xmlTextId);

subroot.AppendChild(childElementId);

xmlDoc.DocumentElement.AppendChild(subroot);

 

XmlElement childElementName = xmlDoc.CreateElement("name");

XmlText xmlTextName = xmlDoc.CreateTextNode(txtName.Text);

childElementName.AppendChild(xmlTextName);

subroot.AppendChild(childElementName);

xmlDoc.DocumentElement.AppendChild(subroot);

 

XmlElement childElementSpeciality = xmlDoc.CreateElement("speciality");

XmlText xmlTextSpeciality = xmlDoc.CreateTextNode(cbspecial.Text);

childElementSpeciality.AppendChild(xmlTextSpeciality);

subroot.AppendChild(childElementSpeciality);

xmlDoc.DocumentElement.AppendChild(subroot);

 

xmlDoc.Save(Application.StartupPath + "\\DoctorsList.xml");
[/sourcecode]

Read Data from XML File Using C#

Sample XML File

[sourcecode language="xml"]
<?xml version="1.0" encoding="utf-8"?>

<PatientInfo>

<Patient id=”1”>

<app-no>03</app-no>

<fname>Brian</fname>

<lname>Marsh</lname>

<docId>03</docId>

</Patient>

<Patient id=”2”>>

<app-no>02</app-no>

<fname>Bron</fname>

<lname>Marini</lname>

<docId>01</docId>

</Patient>

</PatientInfo>

[/sourcecode]

The Code

[sourcecode language="csharp"]
XmlDocument doc = new XmlDocument();

doc.Load("files/sampleXML.xml");

 

XmlNodeList patientList = doc.GetElementsByTagName("Patient ");

 

foreach (XmlNode node in patientList)

{

XmlElement patientElement = (XmlElement) node;

 

string first_name = patientElement.GetElementsByTagName("fname")[0].InnerText;

string last_name = patientElement.GetElementsByTagName("lname")[0].InnerText;

string patient_id = "";

 

if (patientElement.HasAttributes)

{

patient_id = patientElement.Attributes["id"].InnerText;

}

 

Console.WriteLine("{0} ({1}) {2}\n", first_name, last_name, patient_id);

}

[/sourcecode]

Delete Data from XML File Using C#

Adding audio with HTML

[sourcecode language="html"]
<object classid="clsid:02BF25D5-8C17-4B23-BC80-D3488ABDDC6B"
codebase="http://www.apple.com/qtactivex/qtplugin.cab" width="200" height="16">

<param name="src" value="fileName.mp3" />
<param name="controller" value="true" />
<param name="autoplay" value="false" />
<param name="autostart" value="0" />
<param name="pluginspage" value="http://www.apple.com/quicktime/download/" />



<object type="audio/x-mpeg" data="fileName.mp3" width="200" height="16">
<param name="src" value="fileName.mp3" />
<param name="controller" value="true" />
<param name="autoplay" value="false" />
<param name="autostart" value="0" />
<param name="pluginurl" value="http://www.apple.com/quicktime/download/" />

</object>



</object>

[/sourcecode]

IE and non-IE browsers treat audio objects in a web page two different ways. Therefore <Object> should be used carefully in order to play the audio in all browsers perfectly. In the code, there are two sections for IE and other browsers like FF.

IE looks for class Id before playing audio. But other browsers do not use this attribute. They rely on the MIME type of the audio object. In the above code commented section is used by non IE browsers to play audio.

Some Other sound formats

au (type="audio/basic")

wav (type="audio/wav" or "audio/x-wav")

ra (type="audio/x-pn-realaudio")

mp3 (type="audio/x-mpeg")

wma (type="audio/x-ms-wma")

Alternatives for class Id

Quicktime player: classid="clsid:02BF25D5-8C17-4B23-BC80-D3488ABDDC6B" codebase="http://www.apple.com/qtactivex/qtplugin.cab"

Windows media Player: classid="clsid:22D6F312-B0F6-11D0-94AB-0080C74C7E95" codebase="http://activex.microsoft.com/activex/controls/mplayer/en/ nsmp2inf.cab#Version=6,0,02,902"

Real Audio: id=RVOCX classid="clsid:CFCDAA03-8BE4-11CF-B84B-0020AFBBCCFA"

Flash Shockwave Player : classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/ swflash.cab#version=8,0,22,0"