I am writing a method, that will read a string, split a string, and then display one of the values in a text field. Here is what I have so far, it is compiling, but when the button is clicked, nothing is populated into the text field. Thanks
import java.io.DataInputStream;
import java.io.InputStream;
import android.app.Activity;
import android.os.Bundle;
import android.widget.*;
import android.view.*;
public class AboutScreen extends Activity{
Button homeButton=null;
Button getReactant1=null;
TextView tv=null;
String is=null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.about);
homeButton=(Button)findViewById(R.id.Home);
homeButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
finish();
getReactant1=(Button)findViewById(R.id.combinationinterface);
getReactant1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String string1 = getResources().getString(R.string.MgandO);
String delims =",";
String[] tokens = string1.split(delims);
String i = null;
tokens[0]= i;
String f = null;
tokens[1]= f;
tv=(TextView)findViewById(R.id.R1TextInput);
is=i;
tv.setText(i);
}
});
}
});}
Because you called the finish() method at the beginning of the onClick(). Which stops your activity without doing the following stuff.
Your first problem is setting OnClickListener of getReactant1 button inside of homeButton's OnClickListener.
Your other problem is using irrelevant variables and not using splitted value at your textView.
Try to use and modify code below:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.about);
homeButton=(Button)findViewById(R.id.Home);
homeButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
finish();
}
});
getReactant1=(Button)findViewById(R.id.combinationinterface);
getReactant1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String string1 = getResources().getString(R.string.MgandO);
String delims =",";
String[] tokens = string1.split(delims);
String is=token[0];
// or set it to another token you want i.e. token[1]
tv=(TextView)findViewById(R.id.R1TextInput);
tv.setText(is);
}
});
}
Related
I am developing an login and register app. The app is supposed to check if the entered data is correct or not while login or register. The login validation works fine but register doesn't validate data. The register button is supposed to check validations after clicking but nothing happens when I click it. There is no error shown in android studio and the app runs fine.
package com.example.investas;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class RegisterActivity extends AppCompatActivity {
private EditText inputUsername,inputEmail,inputPassword,inputCpassword;
Button btnRegister;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
TextView btn=findViewById(R.id.alreadyHaveAccount);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
TextView btn=findViewById(R.id.alreadyHaveAccount);
inputUsername=findViewById(R.id.inputUsername);
inputEmail=findViewById(R.id.inputEmail);
inputPassword=findViewById(R.id.inputPassword);
inputCpassword=findViewById(R.id.inputCpassword);
btnRegister=findViewById(R.id.btnRegister);
btnRegister.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
validations();
}
});
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(RegisterActivity.this,LoginActivity.class));
}
});
}
});
}
private void validations() {
String username=inputUsername.getText().toString();
String email=inputEmail.getText().toString();
String password=inputPassword.getText().toString();
String cpassword=inputCpassword.getText().toString();
if(username.isEmpty() || username.length()<7)
{
showError(inputUsername,"Your username is not valid");
}
else if(email.isEmpty() || !email.contains("#"))
{
showError(inputEmail,"Email is not valid");
}
else if(password.isEmpty() || password.length()<7)
{
showError(inputPassword,"Password must be 7 characters");
}
else if(cpassword.isEmpty() || !cpassword.equals(password))
{
showError(inputCpassword,"Passwords are not matching");
}
else
{
Toast.makeText(getApplicationContext(),"Registration
Successful",Toast.LENGTH_SHORT).show();
}
}
private void showError(EditText input, String your_username_is_not_valid) {
input.setError(your_username_is_not_valid);
input.requestFocus();
}
}
Try to move the following lines out of the OnClickListener, they should be in the onCreate method:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
//...
inputUsername = findViewById(R.id.inputUsername);
inputEmail = findViewById(R.id.inputEmail);
inputPassword = findViewById(R.id.inputPassword);
inputCpassword = findViewById(R.id.inputCpassword);
btnRegister = findViewById(R.id.btnRegister);
btnRegister.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
validations();
}
});
// ...
}
Doing it this way is necessary for it to be cleaner and to work.
private EditText inputUsername,inputEmail,inputPassword,inputCpassword;
Button btnRegister;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
TextView btn=findViewById(R.id.alreadyHaveAccount);
inputUsername=findViewById(R.id.inputUsername);
inputEmail=findViewById(R.id.inputEmail);
inputPassword=findViewById(R.id.inputPassword);
inputCpassword=findViewById(R.id.inputCpassword);
btnRegister=findViewById(R.id.btnRegister);
TextView btn=findViewById(R.id.alreadyHaveAccount);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(RegisterActivity.this,LoginActivity.class));
}
});
btnRegister.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
validations();
}
});
}
This is my code:
package com.example.pembroke.finalalgorhythmic;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
Button asdf;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
asdf = (Button) findViewById(R.id.keybutton);
asdf.setOnClickListener(MainActivity.this);
}
#Override
public void onClick(View v) {
EditText keyInput = (EditText) findViewById(R.id.key);
String notes = keyInput.getText().toString();
}
What I want to do, is create a character array, so that I can use media player class to play certain sounds based on the user input after my button is clicked. Any ideas?
Have you tried
notes.toCharArray() yet?
EDIT: Long version
EDIT 2: Sample implementation
MediaPlayer mp;
char[] currentNotes;
int noteIndex;
// Create the mp in onCreate and register your onCompletion callback
#Override
public void onClick(View v) {
EditText keyInput = (EditText) findViewById(R.id.key);
String notes = keyInput.getText().toString();
currentNotes = notes.toCharArray();
noteIndex = 0;
mp.setDataSource(getNoteResource(currentNotes[0]));
mp.start();
}
// Convert tone values into
public int getNoteResource(char tone) {…}
#Override
public void onCompletion(MediaPlayer mp) {
if(++noteIndex < currentNotes.length) {
mp.setDataSource(getNoteResource(currentNotes[noteIndex]));
mp.start();
}
}
I encountered an issue and couldn't resolve in Android Studio. The setOnClickListener remains red and doesn't work unless I get rid of my "loseStarter1" button name.
Note: Starter1 is a button, I'm trying to make it disappear when clicked by the user. My real code starts when I introduce the loseStarter1 button.
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class game1 extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game1);
}
Button loseStarter1;
loseStarter1 = (Button) findViewById(R.id.Starter1);
loseStarter1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
loseStarter1.setVisibility(View.GONE);
}
})
}
Much appreciated.
You're missing a semicolon to end the new View.OnClickListener() { ... statement as well as that block not being inside of a method.
Not only move this code into the onCreate method, make sure you end it with a semicolon.
loseStarter1 = (Button) findViewById(R.id.Starter1);
loseStarter1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
loseStarter1.setVisibility(View.GONE);
}
}); // Add the semicolon here
It should look like this:
public class game1 extends AppCompatActivity {
Button loseStarter1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game1);
loseStarter1 = (Button) findViewById(R.id.Starter1);
loseStarter1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
loseStarter1.setVisibility(View.GONE);
}
}); //added semicolon
} // ends onCreate method
} // ends class
Your Button variable declaration and OnClickListener initialization is outside of the onCreate() method. Use the following code:
package com.cutting_edge_tech.mentalenhancementapp;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class game1 extends AppCompatActivity {
private Button loseStarter1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game1);
loseStarter1 = (Button) findViewById(R.id.Starter1);
loseStarter1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
loseStarter1.setVisibility(View.GONE);
}
});
}
}
Move below code inside onCreate()
loseStarter1 = (Button) findViewById(R.id.Starter1);
loseStarter1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
loseStarter1.setVisibility(View.GONE);
}
});
This is how i do it.
1) first make the class implement the interface View.OnClickListener, this let you handle the button clic event:
public class game1 extends AppCompatActivity implements View.OnClickListener;
2) second create the interface method to handle event.
#Override
public void onClick(View view)
{
if(view.getId()==R.id.Starter1)
{
view.setVisibility(View.GONE);
}
}
3) OnCreate methods is the best way to find objects and set properties.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game1);
loseStarter1= (Button) findViewById(R.id.Starter1);
if(loseStarter1!=null){
loseStarter1.setOnClickListener(this);
}
}
all code :
package com.cutting_edge_tech.mentalenhancementapp;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class game1 extends AppCompatActivity implements View.OnClickListener {
private Button loseStarter1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game1);
loseStarter1 = (Button) findViewById(R.id.Starter1);
if(loseStarter1!=null){
loseStarter1.setOnClickListener(this);
}
}
#Override
public void onClick(View view)
{
if(view.getId()==R.id.Starter1)
{
view.setVisibility(View.GONE);
}
}
}
Advice:
Rename class to Game1.
The application is crashing when pressing the Computecost button
package com.example.hw_3;
import android.os.Bundle;
import android.app.Activity;
import android.view.*;
import android.widget.*;
import android.content.*;
public class ShoppingExpensesPage extends Activity
{
TextView et;
Button computecost;
Button save;
Button cancel;
RadioGroup drinks;
RadioButton drink;
int tottalcost=0;
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.second);
et=(TextView)findViewById(R.id.tv11);
Bundle extra = getIntent().getExtras();
String val1 = extra.getString("value");
et.setText(val1);
computecost=(Button)findViewById(R.id.btn11);
computecost.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View view)
{
String val;
int selectedId = drinks.getCheckedRadioButtonId();
drink = (RadioButton)findViewById(selectedId);
val=(String) drink.getText();
if(val=="Juice")
{tottalcost=tottalcost+3;
}
else if (val=="Cola")
{
tottalcost=tottalcost+2;
}
et.setText(Integer.toString(tottalcost));
}
});
save=(Button)findViewById(R.id.btn21);
save.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v) {
Intent returnIntent = new Intent();
String str=Integer.toString(tottalcost);//(String) et.getText();
returnIntent.putExtra("return", str);
setResult(RESULT_OK,returnIntent);
finish();
}
});
}
}
You haven't set the view for drinks.
int selectedId = drinks.getCheckedRadioButtonId();
Find a view for it, before computecost.setOnClickListener:
drinks = (RadioGroup) findViewById(...);
This is the wrong way to compare Strings
if(val=="Juice")
In Java, "==" compares the reference of the Objects but not their values. You need to use .equals()
if("Juice".equals(val))
{ // do something }
If this doesn't solve your problem then please post the logcat from the error but this still needs to be changed.
I am building a larger app and I made this small one just to figure out how to accomplish getting text from user input however it is not working. If I create a string reference at the Text property of my EditText field it works ok. If I leave it blank and enter the text into the field when the application runs in my emulator it does not work. Any ideas.
package com.example.stringtest;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.Button;
public class Main extends Activity {
EditText display;
EditText displayTwo;
String displayContents;
Button displayText;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mainlayout);
display = (EditText) findViewById(R.id.editText1);
displayContents = display.getText().toString();
displayTwo = (EditText) findViewById(R.id.editText2);
displayText = (Button) findViewById(R.id.button1);
displayText.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
displayTwo.setText(displayContents);
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.mainlayout, menu);
return true;
}
}
Try this instead!
displayText.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
displayContents = display.getText().toString();
displayTwo.setText(displayContents);
}
});
displayContents = display.getText().toString();
The displayContents will not be updated when the text inside the EditText changes.
Instead of doing this you should call getText() every time you want to get the current text value.
If you want to be notified every time the text in the EditText is being changed then you should add a listener to the appropiate event. In this case it's EditText.addTextChangedListener.
More information about that:
http://developer.android.com/reference/android/widget/TextView.html#addTextChangedListener(android.text.TextWatcher)