Develop Reference

Android - How to calculate one edit text and divide another value?

I am a total beginner, I am wondering if anyone could help me out with the code. I am trying to make ideal daily water intake apps.
There will be only one edit text for user to input their weight and I want it to divide for example 0.024. Have button to calculate and then display the answer on screen.
public class WaterCalculate extends Activity {
//Declare textviews as fields, so they can be accessed throughout the activity.
EditText weightuser;
TextView tv4;
ImageButton calculate;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.water_calculate);
//Bind the EditText views
weightuser = (EditText)findViewById(R.id.weight);
tv4 = (TextView)findViewById(R.id.res);
calculate = (ImageButton)findViewById(R.id.calc);
calculate.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
calculate();
}
});
}
private void calculate() {
//get entered texts from the edittexts,and convert to integers.
Double value1 = Double.parseDouble(weightuser.getText().toString());
//do the calculation
Double calculatedValue = (value1/0.024);
//set the value to the textview, to display on screen.
tv4.setText(String.valueOf("You need " + calculatedValue + "\nliters of water per day" ));
}
}
When i run the apps the button to calculate its not working and it show the app has stopped. Appreciate for the help.

I thought the problem is in this line.
tv4.setText(String.valueOf("You need " + calculatedValue + "\nliters of water per day" ));
Give a try like this...
tv4.setText("You need "+Double.toString(calculatedValue)+"\nliters of water per day");
and also ensure that you catched the exceptions at necessary places like converting editText value into double.

Try the below code, am sure it will work, when you use click listener for button you should use View.Onclick
class WaterCalculate extends Activity {
// Declare textviews as fields, so they can be accessed throughout the
// activity.
EditText weightuser;
TextView tv4;
ImageButton calculate;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.water_calculate);
// Bind the EditText views
weightuser = (EditText) findViewById(R.id.weight);
tv4 = (TextView) findViewById(R.id.res);
calculate = (ImageButton) findViewById(R.id.calc);
calculate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
calculate();
}
});
}
private void calculate() {
// get entered texts from the edittexts,and convert to integers.
Double value1 = Double.parseDouble(weightuser.getText().toString());
// do the calculation
Double calculatedValue = (value1 / 0.024);
// set the value to the textview, to display on screen.
tv4.setText(String.valueOf("You need " + calculatedValue
+ "\nliters of water per day"));
}
}

how to get multiple edittext value from child view

I have one main layout with one LinearLayout. In this LinearLayout I inflates xml layouts that contain a form with multiple edittext fields(4 EditText) in it. every time i click on add button xml layouts that contain a form with multiple edittext fields(4 EditText) add in linearlayout.
On first attempt I show only one form. There is button for adding more forms. Suppose If user clicks on "Add" button two times then user have three total forms. I successfully get all these three forms.
i am set Tag child view so easy to get one bye one edittext value
but my problem is when i click on save button all edittext data
get and add in array ..
Button buttonAdd = (Button) findViewById(R.id.pdBtnAddDoc);
buttonAdd.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
myRoot = (LinearLayout) findViewById(R.id.linearLayoutAdd);
LayoutInflater inflater = (LayoutInflater)PrimaryDoctorFragment.this.getSystemService(getApplicationContext().LAYOUT_INFLATER_SERVICE);
childView = inflater.inflate(R.layout.fragment_primary_doc_add,myRoot);
// childView.setId(tag++);
childView.setTag(tag++);
}
});
here is my save button:-
btnSave.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
for (int i = 0; i < tag; i++) {
System.out.println("i:- " + i);
View aView = myRoot.findViewById(i);
EditText name = (EditText) aView
.findViewById(R.id.childEtName);
Log.d("Gettext :- ", name.getText().toString());
}
}
});
on save button all four text field data get and add in array..

How to change a sting Variable name dynamically and programatically, this is challenging

I have MainText1 displays a text, when you click on button 3 in the Menu MainText1 displays text3 which is coming from the super class Text. What I want is that dynamically when you click on any button it reads the number and displayed the respective text, that's all about. ;)
I want to get rid of switch case in my activity, so I'm trying now for 2days :( to change the name of the string variable dynamically, but I think I'm using a wrong code as string variable is different from resources (confused), here's my code, this really challenging me this weekend:
public class MainText1 extends Text {
String
tx1=text1,tx2=text2,tx3=text3,
tx,stringReceived;//text1,text2...textn strings coming from the Super class Text
num = Integer.parseInt(getIntent().getStringExtra("somekey1")); // this data is coming from the menu, it depends on which button is clicked
tx="text"+num; // text is the name of the string variable, it should be in format like that : text1,text2,...textn which have predefined string content
stringId = getApplicationContext().getResources().getIdentifier(tx, "string", getPackageName());
if (stringId > 0) {
stringReceived=getApplicationContext().getResources().getString(stringId);

I guess what you're trying to do is to change a TextView contents. So, you could do the following:
public YourActivity extends Activity {
//Here you will declare your layout items
private Button button1;
private Button button2;
private Button button3;
private TextView txtView;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.your_layout);
//Here you will get you layout elements
button1 = (Button) findViewById(R.id.button1_id);
button2 = (Button) findViewById(R.id.button2_id);
button3 = (Button) findViewById(R.id.button3_id);
txtView = (TextView) findViewById(R.id.txtview_id);
//Now you will have to set the onClickListeners
button1.addOnCLickListener(new OnClickListener() {
#Override
private onClick() {
//Set the text in the text view to the string related
//to button1
txtView.setText(getResources()
.getString(R.string.button1_string);)
}
});
button2.addOnCLickListener(new OnClickListener() {
#Override
private onClick() {
//Set the text in the text view to the string related
//to button2
txtView.setText(getResources()
.getString(R.string.button2_string);)
}
});
button3.addOnCLickListener(new OnClickListener() {
#Override
private onClick() {
//Set the text in the text view to the string related
//to button3
txtView.setText(getResources()
.getString(R.string.button3_string);)
}
});
}
}
This should do the trick. Although, like the other guys suggested it, you should take a look at some tutorials before coding on

Setting EditText values on button press to a custom object's values

I'm working on an app that's main layout consists of a row of buttons on top of a LinearLayout which holds a column of EditTexts. I've created a Form object to hold all the values to be displayed in the Editexts, and there will be a Form object for every button in the row. Each button is clicked to change the form's data to show the values held in each Form object. I have the Form objects kept in a List called formList, so that I can access each one when the corresponding button is pressed.
When I click one of the buttons, I want the EditText values to change to a different set of values which correspond to that button. But when I click these buttons, the previously entered values do not show up.
When I click Next Drink, it dynamically creates a button as well as a Form object, and clears the EditTexts so that it looks like a new form has been created for the new button. I should then be able to add strings to the EditTexts, and the strings should be stored in the Form object so that if I click that button again, the Form object will fill the EditTexts with the strings stored in that object.
So, if I click button 3 after having clicked button 2, it should set the text of each EditText to the values contained in the the third Form object, which contains strings for Name, Volume, Percentage, Price, and Quantity.
My problem is the values do not show up in the EditTexts after clicking a button. So if I click Button 3, the values from Form 3 don't show up. I've been at this for a long time and cannot figure out why, so I'd really appreciate any help. Here is the activity:
package com.example.DrinkApp;
import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.*;
import java.util.ArrayList;
import java.util.List;
public class MyActivity extends Activity {
/**
* Called when the activity is first created.
*/
//view variables
final Button newDrink[] = new Button[100];
LinearLayout drinkSelectionContainer;
EditText name;
EditText vol;
EditText perc;
EditText pri;
AutoCompleteTextView quant;
//counters
int numOfDrinks = 0;
int selectedForm = 0;
//array to hold all Form objects.
List<Form> formList = new ArrayList<Form>();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//get views
drinkSelectionContainer = (LinearLayout) findViewById(R.id.drinkSelectContainer);
name = (EditText) findViewById(R.id.etName);
vol = (EditText) findViewById(R.id.etVol);
perc = (EditText) findViewById(R.id.etPerc);
pri = (EditText) findViewById(R.id.etPrice);
quant = (AutoCompleteTextView) findViewById(R.id.etQuantity);
Button saveDrink = (Button) findViewById(R.id.bSaveForm);
Button nextDrink = (Button) findViewById(R.id.bNextDrink);
Button crunkOut = (Button) findViewById(R.id.bCalc);
///////////////////////// next drink method
addNewDrinkButton();
name.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {
}
#Override
public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
formAdd();
}
#Override
public void afterTextChanged(Editable editable) {
// mNames.add(selectedForm, name.getText().toString());
// newDrink[selectedForm].setText(name.getText().toString());
}
});
nextDrink.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
addNewDrinkButton();
}
});
}
//listener for drink select buttons. when button is clicked, it finds out which one it was,
//and then displays the correct values.
public View.OnClickListener drinkSelectListener = new View.OnClickListener() {
public void onClick(View v) {
selectedForm = v.getId();
Form form = formList.get(selectedForm);
Button v1 = (Button) findViewById(selectedForm);
v1.setText(" " + selectedForm);
// Do something depending on the value of the tag
Log.v("My Logs:", "Select Drink " + selectedForm + " button pressed.");
Log.v("My Logs:", "Drink " + selectedForm + " name: " + form.getName());
formDisplay(form);
}
};
private void addNewDrinkButton() {
formClear();
formAdd();
numOfDrinks++;
selectedForm = numOfDrinks;
Log.v("My Logs:", "Next Drink button pressed.");
newDrink[numOfDrinks] = new Button(getBaseContext());
newDrink[numOfDrinks].setOnClickListener(drinkSelectListener);
newDrink[numOfDrinks].setId(numOfDrinks);
newDrink[numOfDrinks].setText("" + selectedForm);
newDrink[numOfDrinks].setLayoutParams(new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT));
// name.setText("Drink " + (numOfDrinks+1));
drinkSelectionContainer.addView(newDrink[numOfDrinks]);
//TODO: save form values, clear edit texts, and create new variables for edittexts.    
}
void formAdd(){
Form tempForm = new Form();
tempForm.setId(selectedForm);
tempForm.setName(name.getText().toString());
tempForm.setVolume(vol.getText().toString());
tempForm.setPercentage(perc.getText().toString());
tempForm.setPrice(pri.getText().toString());
tempForm.setQuantity(quant.getText().toString());
formList.add(selectedForm, tempForm);
}
void formDisplay(Form form){
name.setText(form.getName());
vol.setText(form.getVolume());
perc.setText(form.getPercentage());
pri.setText(form.getPrice());
quant.setText(form.getQuantity());
}
void formClear(){
name.setText("");
vol.setText("");
perc.setText("");
pri.setText("");
quant.setText("");
}
}
!Here's the main layout. So if I click button 4, I want to have the EditTexts display the values
I'd entered the last time I'd clicked on it. It's really very simple.

You are calling formClear() before formAdd()?

Setting EditText values on button press
edittext.setText("nexteditText");
edittext.requestfocus();

show the text of an EditText into a TextView

Describing the functionality of my application: I have put in a Relative Layout a TextView, an EditText and a button. All I am trying to do is: when the user writes something in the EditText and push the button, then the content of the EditText is appeared in the TextView(just like a chat-virtual chat). Everything works perfectly, but when the EditText is empty,and the button get pushed, an empty line is appeared in the TextView(and i don't want to..). Although I've tried to solve it using an if the empty line is still appearing in the TextView. I would be really greatfull, if you could help!!! Than you in advance!
Here is my code:
package teiath.android.appliacation;
import android.app.Activity;
import android.os.Bundle;
import android.text.method.ScrollingMovementMethod;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class M_chat extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
/**Code for the scroll bars in the TextView. */
final TextView tv = (TextView)findViewById(R.id.TEXT_VIEW);
tv.setMovementMethod(new ScrollingMovementMethod());//for the scroll bars
/** Code for the scroll bars in the EditText. */
final EditText wr = (EditText)findViewById(R.id.EDIT_TEXT);
wr.setMovementMethod(new ScrollingMovementMethod());//for the scroll bars
final Button button = (Button) findViewById(R.id.btn1);//find the button by id in main.xml
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Perform action on click
String wrcontent = wr.getText().toString();//gets the text of the EditText and put it in "tvcontent" variable.
String tvcontent = tv.getText().toString();//gets the text of the textView and put it in "tvcontent" variable.
if (wrcontent!="")//if the EditText is not empty
{
//check if the TextView is empty or not
if (tvcontent!="")//If it is not empty...
{
tv.setText(tvcontent + "\n" + wrcontent);//add its current(TextView's text) text, new line and the text of the EditText as the new text of TextView.
//tv.setVisibility(0);//makes visible the textView with the cloud1.png background
wr.setText("");//set the text of the Edit Text as empty
//wrcontent = "";
}
else//if the TextView is empty...
{
tv.setText(wrcontent);//add the text of the editText as the new text of the TextView
wr.setText("");
}
}
/**if (wrcontent=="")
{
}*/
//finish();
}
});
}
}

Don't use !="" for String comparison. To check for empty text, use something like
if ( wrcontent != null && wrcontent.trim().length() == 0 ) {
Better yet, include Guava libraries in your code.