1 reply to this topic

[retry56]

Level: Easy
Material: - Using EditText, Button, TextView, String to Integer conversion with parseInt, conversion String with toString.

1. Open Eclipse [/ b], create a new project adjusted as shown below:

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2. Click Finish, on the left hand side go into the folder layout select main.xml [/ b]

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3. That we will create is to make 2 widgets EditText [/ i] as input integer, 4 Button [/ i] for the +, -, *, / and a TextView [/ i] for displays the results of the calculation.

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 <? Xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
    android: orientation = "vertical"
    android: layout_width = "fill_parent"
    android: layout_height = "fill_parent"
    >
    <EditText
    android: id = "@ + id/input1"
    android: layout_width = "fill_parent"
    android: layout_height = "wrap_content"
    android: numeric = "integer"
    android: text = "0"
    />
    <EditText
    android: id = "@ + id/input2"
    android: layout_width = "fill_parent"
    android: layout_height = "wrap_content"
    android: numeric = "integer"
    android: text = "0"
    />
<LinearLayout
android: layout_width = "fill_parent"
android: layout_height = "wrap_content"
>
<Button
android: id = "@ + id / add"
android: layout_width = "fill_parent"
android: layout_height = "wrap_content"
android: layout_weight = "1"
android: text = "+"
> </ Button>
<Button
android: id = "@ + id / less"
android: layout_width = "fill_parent"
android: layout_height = "wrap_content"
android: layout_weight = "1"
android: text = "-"
> </ Button>
<Button
android: id = "@ + id / time"
android: layout_width = "fill_parent"
android: layout_height = "wrap_content"
android: layout_weight = "1"
android: text = "*"
> </ Button>
<Button
android: id = "@ + id / for"
android: layout_width = "fill_parent"
android: layout_height = "wrap_content"
android: layout_weight = "1"
android: text = "/"
> </ Button>

</ LinearLayout>
<TextView
android: id = "@ + id / results"
    android: layout_width = "fill_parent"
    android: layout_height = "wrap_content"
    android: gravity = "center"
    android: text = "Results"
    />
    
    
   <! - DiskusiAndroid.com ->
    <TextView
    android: layout_width = "fill_parent"
    android: layout_height = "wrap_content"
    android: layout_marginTop = "250px"
    android: gravity = "center"
    android: text = "diskusiAndroid.com"
    />
        <! - DiskusiAndroid.com ->
    
</ LinearLayout>

4. After setting the display main.xml , now set the code to hook Main.java with main.xml . Open Main.java .

5. The first do is create a variable of each widget that we have created is [i] Button , [i] EditText and [i] Textview . Create a variable like the following code:

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 EditText input1, input2;
Button added, less, times, for;
TextView results;

    @ Override
    public void OnCreate (Bundle savedInstanceState) {
        super.onCreate (savedInstanceState);
        setContentView (R.layout.main);
        
        input1 = (EditText) findViewById (R.id.input1);
        input2 = (EditText) findViewById (R.id.input2);
        result = (TextView) findViewById (R.id.hasil);
        added = (Button) findViewById (R.id.tambah);
        less = (Button) findViewById (R.id.kurang);
        time = (Button) findViewById (R.id.kali);
        for = (Button) findViewById (R.id.bagi); [/ code] [/ spoiler]

6. Because the application will work if we click the button +,-,*,/ then each widget [i] Button [/ i] should be in [b] setOnClickListener [/ b].
[Spoiler] [code] tambah.setOnClickListener (this);
        kurang.setOnClickListener (this);
        kali.setOnClickListener (this);
        bagi.setOnClickListener (this); 

7. After adding [b] setOnClickListener do not forget to implement [b] OnClickListener [/ b].

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 public class Main extends Activity implements OnClickListener {

8. Then create the function [b] onClick for the button can be clicked.

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 public void onClick (View v) {
/ / TODO Auto-generated method stub
int one = Integer.parseInt (input1.getText (). toString ());
int two = Integer.parseInt (input2.getText (). toString ());
switch (v.getId ()) {
R.id.tambah case:
hasil.setText (Integer.toString (one + two));
break;
R.id.kurang case:
hasil.setText (Integer.toString (one-two));
break;
R.id.kali case:
hasil.setText (Integer.toString (one * two));
break;
R.id.bagi case:
hasil.setText (Double.toString (one / two));
break;
}
} 

In the above code we first create an integer variable one and two. Because the input of [i] EditText [/ i] form of String so it must be converted to integer with parseInt. Use the switch to set any button to be clicked in accordance +,-,*,/. button Before showing the results of the calculations, it should change back the results of the calculations in the form of an integer to a string by toString ();.

Edited by retry56, 02 March 2011 - 06:35 AM.

[darko100]

First advice that you need Android SDK installed , Java installed , Eclipse installed , Android SDK platforms downloaded.

Also you will need to set up where is your Android SDK located , to make PATH=Java location , to select a Android SDK (for example 2.3) platform.

http://www.makeuseof...id-application/ I would suggest this tutorial which explains everything which can be pain-in-the-*bottom* if you don't follow tutorials and just view the android.com one

PS. Why DiskusAndroid.com isn't working? The one advertised on your signature