Android应用程序意外停止

Question

我是Android开发的新手，并尝试创建我的第一个Android应用程序。我有一个简单的登录应用程序，但当我在模拟器/我自己的设备上运行此应用程序时，它给了我错误：

App意外停止了。发射器已经崩溃。

我试图弄清楚什么是错的，但没有任何想法。我已经对配置文件进行了更改，例如增加堆和ram大小，但它不起作用。我认为我的代码中存在一些错误，因为应用程序在模拟器和Android设备上都崩溃了。

这是我的代码：

LoginScreen1.java类

package com.example.dell.creditcard;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;

import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class LoginScreen1 extends Activity implements AdapterView.OnItemSelectedListener {
    SharedPreferences sharedPreferences =  getSharedPreferences("userLoginDetails",MODE_PRIVATE);
    SharedPreferences.Editor  edit= sharedPreferences.edit();
    EditText editText1 = (EditText) findViewById(R.id.Edit1);
    EditText editText2 = (EditText) findViewById(R.id.Edit2);
    EditText editText3 = (EditText) findViewById(R.id.Edit3);
    EditText editText4 = (EditText) findViewById(R.id.Edit4);
    EditText editText5 = (EditText) findViewById(R.id.Edit5);
    EditText editText6 = (EditText) findViewById(R.id.Edit6);
    Spinner spinner =  (Spinner) findViewById(R.id.Spinner);
    Spinner cardType;
    private String[] card = { "JCB", "Master", "Visa"};
    boolean flag = false;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.LoginScreen1);
        cardType = (Spinner) findViewById(R.id.Spinner);
        cardType.setPrompt("Choose Card");
        ArrayAdapter<String> adapter_state = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, card);
        adapter_state
                .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        cardType.setAdapter(adapter_state);
        cardType.setOnItemSelectedListener(this);
    }

    public void onItemSelected(AdapterView<?> parent, View view, int position,
                               long id) {
        cardType.setSelection(position);
        String selState = (String) cardType.getSelectedItem();
    }


    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    public boolean isFullWidth(String s){
        boolean bool = false;
        int length = s.length();

        for (int i = 0; i < length; i++) {
            char c = s.charAt(i);
            if ('\uFF01' <= c && c <= '\uFF60' || '\uFFE0' <= c && c <= '\uFFE6') {
                continue;
            }
            bool = true;
            break;
        }
        return bool;

    }

    public boolean isHalfWidth(String s){
        boolean bool = false;
        int length = s.length();

        for (int i = 0; i < length; i++) {
            char c = s.charAt(i);
            if ('\u0000' <= c && c <= '\u00FF' || '\uFF61' <= c && c <= '\uFFDC' || '\uFFE8' <= c && c <= '\uFFEE') {
                continue;
            }
            bool = true;
            break;
        }
        return bool;

    }

    public void send(View view) {

        if (editText1.getText().toString().equals("")) {
            editText1.setError("Username is required");
            flag = true;
        }

        if (editText2.getText().toString().equals("")) {
            editText2.setError("Password is required");
            flag = true;

        }

        if (editText2.getText().toString().length() != 4) {
            editText2.setError("password should only contain 4 digits");
            flag = true;

        }


        if (editText3.getText().toString().equals("")) {
            editText3.setError("Confirm Password is required");
            flag = true;

        }

        if (editText3.getText().toString().length() != 4) {
            editText3.setError("confirm password should only contain 4 digits");
            flag = true;

        }


        if (!editText2.getText().toString().equals(editText3.getText().toString())) {
            editText3.setError("Password and Confirm Password must be same");
            flag = true;
        }

        String s = editText4.getText().toString();
        if(s == null){
            editText4.setError("Name(Kanji) is required");
            flag =true;
        }
        if(isFullWidth(s)){
            editText4.setError("Characters must be Full-Width Characters");
            flag =true;
        }

        s = editText5.getText().toString();
        if(s == null){
            editText4.setError("Name(Roman) is required");
            flag =true;
        }
        if(isHalfWidth(s)){
            editText4.setError("Characters must be Half-Width Characters");
            flag =true;
        }

        if (!isEmailValid(editText6.getText().toString())){
            editText6.setError("Email is not valid");
            flag = true;

        }
        /*in.putExtra("com.example.dell.creditcard.m1",editText1.getText().toString());
        in.putExtra("com.example.dell.creditcard.m2",editText2.getText().toString());
        in.putExtra("com.example.dell.creditcard.m3",editText3.getText().toString());
        in.putExtra("com.example.dell.creditcard.m4",editText4.getText().toString());
        in.putExtra("com.example.dell.creditcard.m5",editText5.getText().toString());
        in.putExtra("com.example.dell.creditcard.m6",editText6.getText().toString());
        in.putExtra("com.example.dell.creditcard.m", spinner.getSelectedItem().toString());*/
        edit.putString("com.example.prateeksharma.userName",editText1.getText().toString());
        edit.putString("com.example.prateeksharma.password",editText2.getText().toString());
        edit.putString("com.example.prateeksharma.confirmPassword",editText3.getText().toString());
        edit.putString("com.example.prateeksharma.nameKanji",editText4.getText().toString());
        edit.putString("com.example.prateeksharma.nameRoman",editText5.getText().toString());
        edit.putString("com.example.prateeksharma.email",editText6.getText().toString());
        edit.putString("com.example.prateeksharma.cardType", spinner.getSelectedItem().toString());
        edit.apply();
        if(flag) {
            Intent in = new Intent(this, LoginScreen1.class);
            flag= false;
            startActivity(in);
            finish();
        }
        else {
            Intent in = new Intent(this, LoginScreen2.class);
            startActivity(in);
        }


    }
    @Override
    protected void onResume() {

        editText1.setText(sharedPreferences.getString("com.example.prateeksharma.userName",""));

        editText2.setText(sharedPreferences.getString("com.example.prateeksharma.password",""));

        editText3.setText(sharedPreferences.getString("com.example.prateeksharma.confirmPassword",""));

        editText4.setText(sharedPreferences.getString("com.example.prateeksharma.nameKanji",""));

        editText5.setText(sharedPreferences.getString("com.example.prateeksharma.nameRoman",""));

        editText6.setText(sharedPreferences.getString("com.example.prateeksharma.email",""));

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, card);
            adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            spinner.setAdapter(adapter);
            if (!sharedPreferences.getString("com.example.prateeksharma.cardType","").equals(null)) {
                int spinnerPosition = adapter.getPosition(sharedPreferences.getString("com.example.prateeksharma.cardType",""));
                spinner.setSelection(spinnerPosition);
                spinnerPosition = 0;
            }
        super.onResume();
    }


    public static boolean isEmailValid(String email) {
        boolean isValid = false;

        String expression = "^[\\w\\.-]+@([\\w\\-]+\\.)+[A-Z]{2,4}$";
        CharSequence inputStr = email;

        Pattern pattern = Pattern.compile(expression, Pattern.CASE_INSENSITIVE);
        Matcher matcher = pattern.matcher(inputStr);
        if (matcher.matches()) {
            isValid = true;
        }
        return isValid;
    }


    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}
 This class is a simple login class. I'm storing values in shared preference so that I can reset the values of the login form when user returns to this activity as I'm creating the new instance of activity every time.

我的xml文件是：

<?xml version="1.0" encoding="utf-8"?>
<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/ScrollView01"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:scrollbars="vertical">
    <LinearLayout
        android:layout_width="fill_parent"
        android:orientation="vertical"
        android:layout_height="fill_parent"
        >

        <!--Put form controls here-->

        <TextView
            android:id="@+id/TextViewTitle"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:text="@string/FromTitle"
            android:textSize="20pt"
            android:gravity="center">
        </TextView>

        <View
            android:layout_width="fill_parent"
            android:layout_height="30dp">
        </View>


        <TextView
            android:id="@+id/Spin"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:text="@string/cardType"
            android:textSize="10pt">
        </TextView>


        <Spinner
            android:id="@+id/Spinner"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp" />

        <View
            android:layout_width="fill_parent"
            android:layout_height="30dp">
        </View>


        <TextView
            android:id="@+id/username"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:text="@string/username"
            android:textSize="10pt">
        </TextView>


        <EditText
            android:id="@+id/Edit1"
            android:layout_height="wrap_content"
            android:inputType="text"
            android:layout_width="fill_parent">
        </EditText>

        <View
            android:layout_width="fill_parent"
            android:layout_height="30dp">
        </View>


        <TextView
            android:id="@+id/password"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:text="@string/password"
            android:textSize="10pt">
        </TextView>


        <EditText
            android:id="@+id/Edit2"
            android:layout_height="wrap_content"
            android:inputType="numberPassword"
            android:layout_width="fill_parent">
        </EditText>

        <View
            android:layout_width="fill_parent"
            android:layout_height="30dp">
        </View>


        <TextView
            android:id="@+id/confirmPassword"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:text="@string/confirmpassword"
            android:textSize="10pt">
        </TextView>

        <EditText
            android:id="@+id/Edit3"
            android:layout_height="wrap_content"
            android:inputType="numberPassword"
            android:layout_width="fill_parent">
        </EditText>

        <View
            android:layout_width="fill_parent"
            android:layout_height="30dp">
        </View>


        <TextView
            android:id="@+id/nameKanji"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:text="@string/nameKanji"
            android:textSize="10pt">
        </TextView>


        <EditText
            android:id="@+id/Edit4"
            android:layout_height="wrap_content"
            android:maxLength="10"
            android:layout_width="fill_parent">
        </EditText>

        <View
            android:layout_width="fill_parent"
            android:layout_height="30dp">
        </View>


        <TextView
            android:id="@+id/nameRoman"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:text="@string/nameRoman"
            android:textSize="10pt">
        </TextView>


        <EditText
            android:id="@+id/Edit5"
            android:layout_height="wrap_content"
            android:inputType="text"
            android:maxLength="20"
            android:layout_width="fill_parent">
        </EditText>

        <View
            android:layout_width="fill_parent"
            android:layout_height="30dp">
        </View>


        <TextView
            android:id="@+id/email"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:text="@string/email"
            android:textSize="10pt">
        </TextView>


        <EditText
            android:id="@+id/Edit6"
            android:layout_height="wrap_content"
            android:inputType="textEmailAddress"
            android:layout_width="fill_parent">
        </EditText>

        <View
            android:layout_width="fill_parent"
            android:layout_height="30dp">
        </View>


        <Button
            android:id="@+id/Next"
            android:layout_height="wrap_content"
            android:text="@string/data"
            android:onClick="send"
            android:layout_width="fill_parent">
        </Button>

    </LinearLayout>
</ScrollView>

有人可以解释一下导致应用程序崩溃的错误吗？

Answer 1

移动

SharedPreferences sharedPreferences =  getSharedPreferences("userLoginDetails",MODE_PRIVATE);
SharedPreferences.Editor  edit= sharedPreferences.edit();

EditText editText1 = (EditText) findViewById(R.id.Edit1);
EditText editText2 = (EditText) findViewById(R.id.Edit2);
EditText editText3 = (EditText) findViewById(R.id.Edit3);
EditText editText4 = (EditText) findViewById(R.id.Edit4);
EditText editText5 = (EditText) findViewById(R.id.Edit5);
EditText editText6 = (EditText) findViewById(R.id.Edit6);
Spinner spinner =  (Spinner) findViewById(R.id.Spinner);

在onCreate(...)

之后的setContentView(....)中

Answer 2

写下你的活动：

public class ActivityTest extends Activity {

    SharedPreferences sharedPreferences;
    SharedPreferences.Editor edit;
    EditText editText1;
    EditText editText2;
    EditText editText3;
    EditText editText4;
    EditText editText5;
    EditText editText6;
    Spinner spinner;
    Spinner cardType;
    private String[] card = { "JCB", "Master", "Visa" };
    boolean flag = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContetentView(R.layout.activity_main);

        editText1 = (EditText) findViewById(R.id.Edit1);
        editText2 = (EditText) findViewById(R.id.Edit2);
        editText3 = (EditText) findViewById(R.id.Edit3);
        editText4 = (EditText) findViewById(R.id.Edit4);
        editText5 = (EditText) findViewById(R.id.Edit5);
        editText6 = (EditText) findViewById(R.id.Edit6);
        spinner = (Spinner) findViewById(R.id.Spinner);

        sharedPreferences = getSharedPreferences(
                "userLoginDetails", MODE_PRIVATE);

        edit = sharedPreferences.edit();

    }
}