[英]Android app crashes when EditText is blank and button pressed
[英]Android app crashes when It's trying to get EditText values
我的Android Studio應用程序有問題。 雖然登錄功能可以正常工作。 我的注冊功能有問題。 一旦用戶嘗試成功注冊他/她自己,應用程序就會崩潰(可能是由於NullPointerException)。 問題可能出在postParams函數上。 無論如何,這里是代碼:
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
import org.json.JSONObject;
import java.util.HashMap;
import java.util.Map;
public class RegisterActivity extends Activity{
private EditText txtEmail;
private EditText txtPassword1;
private EditText txtPassword2;
private EditText txtFirstName;
private EditText txtLastName;
private ProgressDialog m_ProgresDialog;
private AccessServiceAPI m_AccessServiceAPI;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
txtEmail = (EditText)findViewById(R.id.txt_email);
txtPassword1 = (EditText)findViewById(R.id.txt_pwd1);
txtPassword2 = (EditText) findViewById(R.id.txt_pwd2);
txtFirstName = (EditText) findViewById(R.id.txt_first_name);
txtLastName = (EditText) findViewById(R.id.txt_last_name);
m_AccessServiceAPI = new AccessServiceAPI();
}
public void btnRegister_Click(View v) {
//Validate input
if("".equals(txtEmail.getText().toString())) {
txtEmail.setError("Email is required!");
return;
}
if("".equals(txtFirstName.getText().toString())) {
txtFirstName.setError("First name is required!");
return;
}
if("".equals(txtLastName.getText().toString())) {
txtLastName.setError("Last name is required!");
return;
}
if("".equals(txtPassword1.getText().toString())) {
txtPassword1.setError("Password is required!");
return;
}
if("".equals(txtPassword2.getText().toString())) {
txtPassword2.setError("Please retype your password!");
return;
}
if(txtPassword1.getText().toString().equals(txtPassword2.getText().toString())) {
//exec task register
new TaskRegister().execute(txtEmail.getText().toString(), txtPassword1.getText().toString());
} else {
txtPassword2.setError("Confirm password does not match!");
}
}
public class TaskRegister extends AsyncTask<String, Void, Integer> {
@Override
protected void onPreExecute() {
super.onPreExecute();
m_ProgresDialog = ProgressDialog.show(RegisterActivity.this, "Please wait", "Registration processing...", true);
}
@Override
protected Integer doInBackground(String... params) {
Map<String, String> postParam = new HashMap<>();
postParam.put("email", params[0]);
postParam.put("password", params[1]); //There is no First name and Last name params because those two lines of code crashes the app. Yet without it, you can't register.
postParam.put("first_name", params[2]);
postParam.put("last_name", params[3]);
try{
String jsonString = m_AccessServiceAPI.getJSONStringWithParam_POST(Common2.SERVICE_API_URL, postParam);
JSONObject jsonObject = new JSONObject(jsonString);
return jsonObject.getInt("result");
}catch (Exception e) {
e.printStackTrace();
return Common2.RESULT_ERROR;
}
}
@Override
protected void onPostExecute(Integer integer) {
super.onPostExecute(integer);
m_ProgresDialog.dismiss();
if(integer == Common2.RESULT_SUCCESS) {
Toast.makeText(RegisterActivity.this, "Registration success", Toast.LENGTH_LONG).show();
Intent i = new Intent();
i.putExtra("email", txtEmail.getText().toString());
i.putExtra("password", txtPassword1.getText().toString());
i.putExtra("first_name", txtFirstName.getText().toString()); //These two lines of code causes the app to crash
i.putExtra("last_name", txtLastName.getText().toString());
setResult(3, i);
finish();
} else if(integer == Common2.RESULT_USER_EXISTS) {
Toast.makeText(RegisterActivity.this, "Username already exists!", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(RegisterActivity.this, "Registration failed!", Toast.LENGTH_LONG).show();
}
}
}}
您可能會收到NullPointer-Exception
因為您嘗試使用param[2]
和param[3]
但是沒有將它們傳遞給Async-Task
。
您的修復將是new TaskRegister().execute(txtEmail.getText().toString(), txtPassword1.getText().toString(), txtFirstName.getText().toString(), txtLastName.getText().toString());
您只傳遞僅傳遞電子郵件和密碼,而您將參數設置為也接受firstName和lastName。 像新的TaskRegister().execute(txtEmail.getText().toString(), txtPassword1.getText().toString(),txtFirstName.getText().toString(), txtLastName.getText().toString());
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