代码中没有错误，但按钮不执行任何操作

Question

我正在开发一个登录和注册应用程序。该应用程序应该检查输入的数据是否正确，而登录或注册。登录验证工作正常，但注册不验证数据。注册按钮应该检查验证后点击，但什么都没有发生，当我点击它。android studio中没有显示错误，应用程序运行正常。

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();
}
}

Answer 1

尝试将以下行移出OnClickListener，它们应该在onCreate方法中:

@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();
}
});
// ...
}

Answer 2

这样做是必要的，以使其更干净，更有效。

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();
}
});
}