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Form validation on Button click in android
(3 answers)
Closed 5 years ago.
I am new in android programming and still learning. for practice i started to create a very simple and basic app which calculate age on button click which take birth year as an input.
i manage to get it working and want to do some validation on it. like i have done validating that the value we provide should not be more than current year and i successfully done that.
Now my problem is that i also want to put validation that if no input is been made and button is pressed then it should alert the user by Toast. So far i have tried doing but every time i press button without anything in editText the app just crash.
here's my code.
calcAge.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if(dob > year){
Toast.makeText(getApplicationContext(), "Provide valid Input", Toast.LENGTH_SHORT).show();
}
else if(String.valueOf(dob) == null){
Toast.makeText(getApplicationContext(), "Please Provide Some Input", Toast.LENGTH_SHORT).show();
}
else{
dob = Integer.parseInt(String.valueOf(inAge.getText()));
currentYear.setText("Your Curret Year is :- " + year);
yourYear.setText("Your Birth Year is :- "+ dob);
int a = year-dob;
finalAns.setText("Your Age is :- " + a);
inAge.setText("");
}
}
});
above code is of button click. Please provide with some solution
I have also tried putting editText1.getText().toString.trim().lenght()==0 in if condition but that also didn't worked and app just crashes.
try this on button click listner
calcAge.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (yourEdittext.getText().toString().equals("")) {
yourEdittext.setError(getString("filed can't be empty"));
yourEdittext.requestFocus();
Toast.makeText(getApplicationContext(), "Please Provide Some Input", Toast.LENGTH_SHORT).show();
}
}
});
Use this:
String dob = yourEditText.getText().toString();
then check it like this:
if (TextUtils.isEmpty(dob)) {
//show toast
}
You have to do validation like this :
doneDetails.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(validationDetails()){
//If get all data do Action
}else{
// Toast.makeText(getApplicationContext(),"Field Missing",Toast.LENGTH_SHORT).show();
}
}
This is the validation part method:
private boolean validationDetails() {
if (userNameET.getText().toString().isEmpty()) {
userNameET.setError("Enter Patient Name");
return false;
}
if (ageET.getText().toString().isEmpty()) {
ageET.setError("Enter Age ");
return false;
}
if (gender.getSelectedItem().toString().isEmpty()) {
Toast.makeText(getApplicationContext(),"Select Gender",Toast.LENGTH_SHORT).show();
return false;
}
return true;
}
On button click, you are checking first if dob is greater than a year. which is not correct. First, check if dob is null or empty. then check for if greater than year
If (dob == null && dob.isEmplty){
Toast.makeText(getApplicationContext(), "Please Provide Some Input", Toast.LENGTH_SHORT).show();
} else if(dob > year){
Toast.makeText(getApplicationContext(), "Provide valid Input", Toast.LENGTH_SHORT).show();
} else {
//do what ever you want
}
try this on your button click :
if ( yourEditText.getText().toString().equal("")) {
Toast.makeText(getApplicationContext(), "Please Give Some Input", Toast.LENGTH_SHORT).show();
}
Related
I am getting an error when I set the counter to subtract and close the application. I get an error "cannot assign value to final variable counter". If the user logins in 3 times with no success quit the application.
final int counter = 3;
//Set the OKButton to accept onClick
OKButton.setOnClickListener(new View.OnClickListener() {
#Override
//once onClick is initalized it takes user to page menu
public void onClick(View v) {
//display text that was inputed for userText and passText
user = userText.getText().toString();
pass = passText.getText().toString();
//create if loop which checks if user and pass equals the credentials
if (user.equals("pshivam") && pass.equals("Bway.857661")) {
//display toast access welcome
String welcome = "Access Granted.";
//Create a Toast to display the welcome string in the MainActivity.
Toast.makeText(MainActivity.this, welcome, Toast.LENGTH_SHORT).show();
setContentView(R.layout.account_main);
}
//create else if loop which checks if user or pass does not equals the credentials
else if (!user.equals("pshivam") || !pass.equals("Bway.857661")){
//displays previous entry
userText.setText(user);
passText.setText(pass);
//allows user to re-enter credentials.
user = userText.getText().toString();
pass = passText.getText().toString();
//display toast access fail
String fail = "Access Denied! Please Try again.";
//Create a Toast to display the fail string in the MainActivity.
Toast.makeText(MainActivity.this, fail, Toast.LENGTH_SHORT).show();
counter--;
if(counter == 0){
finish();
}
}
}
});
}
}
Do something like this :
OKButton.setOnClickListener(new View.OnClickListener() {
int counter = 3;
#Override
//once onClick is initalized it takes user to page menu
public void onClick(View v) {
You can also call a function from inside onClick which will decrement the variable, or use a static field declared in your class
This How to increment a Counter inside an OnClick View Event and How do I use onClickListener to count the number of times a button is pressed? might help.
Edit:
What you are doing in else part doesn't make sense. You are setting text for userText and passText that you just got using getText() from these. Then you are storing these same values to user and pass. But you aren't using these variables anywhere and they get new values when onClick is called again. Why not keep it simple :
else {
//display toast access fail
String fail = "Access Denied! Please Try again.";
//Create a Toast to display the fail string in the MainActivity.
Toast.makeText(MainActivity.this, fail, Toast.LENGTH_SHORT).show();
counter--;
if(counter == 0){
finish();
}
}
I'm new to stackoverflow and android, sorry if i'm wrong. I am trying to check the text fields is empty or not, when the text field is empty, upload button should show please enter title and when user enters the text then only it should upload the image. After entering title then also it again shows the toast.
btnUpload.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (title1.matches("")){
Toast.makeText(getApplicationContext(), "Please enter the Title and Category", Toast.LENGTH_SHORT).show();
} else if(description1.matches("")){
Toast.makeText(getApplicationContext(), "Please Select Category", Toast.LENGTH_SHORT).show();
} else {
flag = 1;
// uploading the file to server
new UploadFileToServer().execute();
}
}
});
Any help would be appreciated.
To check for empty fields, use
if(TextUtils.isEmpty(editText.getText().toString())) {
// do something
}
or if you want to check if string is empty or null use -
if(TextUtils.isEmpty(stringToCheck) {
// do something
}
try this.
Place this code in your button onClickListener:
String mText = mEditText.getText().toString();
if(TextUtils.isEmpty(mText)){
//Do what you want(Edittext is NULL)
}else{
//Do what you want(Not NULL)
}
Try to get value from your edittext like below:
Globally declare variable : -
String editvalue;
In onCreate() :-
EditText youredittext = (EditText)findViewById(R.id.youredittextid);
editvalue = youredittext.getText.toString().trim();
Now in your condition check :
if(editvalue.isEmpty() || editvalue == null){
// Do what you want when editText's value is null or empty
}else{
}
You can also use
TextUtils.isEmpty(CharSequence str)
for empty and null string check.
Returns true if the string is null or 0-length
I have written the simple code for Login authentication with hardcoded password.my problem is evenif I am entering the correct password my control is going in elese loop
edt=(EditText)findViewById(R.id.edt);
btn=(Button)findViewById(R.id.sub);
s1=edt.getText().toString();
btn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Log.d("mynameeeeee",s1);
if(s1=="123")
{
Toast.makeText(getApplicationContext(), "Successful",Toast.LENGTH_LONG).show();
}
else
{
Log.d("coming in elseeeee","coming in elseeeee");
Toast.makeText(getApplicationContext(), "not valid",Toast.LENGTH_LONG).show();
}
}
});
Here's the problem :
You are storing a reference of the edit text content at creation time, when the edit text is empty.
You should retrieve the content of the edit text EVERYTIME you want to compare, which is when the button is clicked in your case :
Do the following :
edt=(EditText)findViewById(R.id.edt);
btn=(Button)findViewById(R.id.sub);
btn.setOnClickListener ( new OnClickListener () {
#Override
public void onClick ( View v ) {
Log.d ( "mynameeeeee" , edt.getText().toString() );
if ( edt.getText().toString().equals ( "123" ) )
{
Toast.makeText(getApplicationContext(), "Successful",Toast.LENGTH_LONG).show();
}
else
{
Log.d("coming in elseeeee","coming in elseeeee");
Toast.makeText(getApplicationContext(), "not valid",Toast.LENGTH_LONG).show();
}
}
});
the string should be compared like:
if(s1.equals("123")) {}
Change your if statement like this
if(s1.equals("123"))
{
Toast.makeText(getApplicationContext(), "Successful",Toast.LENGTH_LONG).show();
}
else
{
Log.d("coming in elseeeee","coming in elseeeee");
Toast.makeText(getApplicationContext(), "not valid",Toast.LENGTH_LONG).show();
}
When comparing strings always use .equals() function
== Checks whether both the variable are referring to same object. In this case since they are referring to different object so the result of == is false.
use equals() method s1.equals("123") to check the content of the string object.
I am developing an android application in which iIhave 4 edittext and below a button. I want to apply validation on each field so that any field is not left blank. I have tried a lot of samples and applied same logic, but its not working.
I have coded for that. My java class is
http://pastebin.com/ZdeYZPxX
But problem is that when I enter first edittext and then click button, it works. Can anyone help me to come out of this problem?
See I have made this function in class
public boolean checkForEmpty(String fieldString) {
if (fieldString.equalsIgnoreCase("")
|| fieldString.equalsIgnoreCase(null))
return true;
else
return false;
}
Then
username = editUserName.getText().toString().trim();
if (checkForEmpty(username)) {
Showalert("Please enter User ID");
editUserName.requestFocus();
}
After showing a Toast telling the user that one of the EditText is empty you should add a return statement to stop the rest of the code(that starts a new Activity) being run until the user fills all EditTexts:
if (un.equals("") || pw.equals("")) {
if (un.equals("")) {
Toast.makeText(BloodPressureScreen.this, "FirstName is empty", Toast.LENGTH_SHORT).show();
return;
} else {
Toast.makeText(BloodPressureScreen.this, "LastName is empty", Toast.LENGTH_SHORT).show();
return;
}
}
if (cn.equals("") || em.equals("")) {
if (cn.equals("")) {
Toast.makeText(BloodPressureScreen.this, "Contact is empty", Toast.LENGTH_SHORT).show();
return;
} else {
Toast.makeText(BloodPressureScreen.this, "Email is empty", Toast.LENGTH_SHORT).show();
return;
}
}
public boolean checkForEmpty(String fieldStr) {
if (fieldStr.length() == 0 )
return true;
else
return false;
}
Im trying to create a button which when pushed reads the edittext box to
Make sure its not blank
Make sure its not the default text in this case "First Name".
However when the button is pushed it still preforms the action even if the edittext text is First Name or blank. Is there an easier way to do this? Also the toast are not made when the text is First Name or blank.
createp.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (fname.getText().toString() != "")
if (fname.getText().toString() != "First Name"){
prefsEditor.putInt("user", 1);
prefsEditor.commit();
}
if (fname.getText().toString() == "")
{
Toast.makeText(createactivity.this, "You need a first name to create a profile!",
Toast.LENGTH_LONG).show();
}
if (fname.getText().toString() == "First Name") {
Toast.makeText(createactivity.this, "You need a first name to create a profile!",
Toast.LENGTH_LONG).show();
}
}});
}
Try this instead:
if (!fname.getText().toString().equals(""))
...
Another example:
if (fname.getText().toString().equals("First Name"))
....