Hi all,
i am new to android development, in fact its my first application. i am making a simple calculator. i just want to know how to get the value of a pressed button.
Any help plz
baig772 19 Web Application Architect
peter_budo 2,532 Code tags enforcer Team Colleague Featured Poster
Depends how you did setOnCLickListener. Can you post your code?
baig772 19 Web Application Architect
How to set OnClickListener?
my code is
package com.calculator;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class CalculatorActivity 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);
String btn_val = b.getText().toString();
EditText edit_text = (EditText)findViewById(R.id.editText1);
edit_text.setText(btn_val);
}
this code is getting the value of button id = button1 and setting it in text feild. i want to do all this work when clicked on any button e.g when clicked on 2, it should print 2 in text feild
peter_budo 2,532 Code tags enforcer Team Colleague Featured Poster
Here is quick leg-up. From code bellow you can see I used onClick parameter in layout. This will call same method for update, but may get heairy in adding more functionality to handle mathematical operations. So you may consider using listeners as I will show at the end where inside the onClick method you will provide logic for what ever has to happen
layout
<?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/display"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="0"
android:gravity="right"
/>
<TableLayout
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:weightSum="4">
<TableRow
android:layout_height="match_parent"
android:layout_width="match_parent"
android:layout_weight="1"
android:weightSum="4">
<Button
android:id="@+id/button1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="1"
android:layout_weight="1"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="2"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button3"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="3"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button_plus"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="+"
android:onClick="updateDisplay"
/>
</TableRow>
<TableRow
android:layout_height="match_parent"
android:layout_width="match_parent"
android:layout_weight="1"
android:weightSum="4">
<Button
android:id="@+id/button4"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="4"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button5"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="5"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button6"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="6"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button_minus"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="-"
android:onClick="updateDisplay"
/>
</TableRow>
<TableRow
android:layout_height="match_parent"
android:layout_width="match_parent"
android:layout_weight="1"
android:weightSum="4">
<Button
android:id="@+id/button7"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="7"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button8"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="8"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button9"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="9"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button_times"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="*"
android:onClick="updateDisplay"
/>
</TableRow>
<TableRow
android:layout_height="match_parent"
android:layout_width="match_parent"
android:layout_weight="1"
android:weightSum="4">
<Button
android:id="@+id/button0"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="0"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button_equals"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="="
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button_divide"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="/"
android:onClick="updateDisplay"
/>
<Button
android:id="@+id/button_clear"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="CE"
android:onClick="updateDisplay"
/>
</TableRow>
</TableLayout>
</LinearLayout>
and activity
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class CalculatorActivity extends Activity {
private EditText display;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
display = (EditText)findViewById(R.id.display);
}
public void updateDisplay(View v){
display.setText(display.getText().toString() + ((Button)v).getText());
}
}
listener example
Button button1 = (Button)findViewById(R.id.button1);
button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
display.setText(display.getText().toString() + ((Button)view).getText());
}
});
When you use this listener remove android:onClick from each button in main.xml
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