Question

嗨，我正在开发一个非常简单的应用程序，但遇到了一些问题。每当我在应用程序上单击此AddTransactions按钮时，应用程序就会崩溃。这是我的首页课程：

package com.example.natpc.moneymanager;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class homepage extends AppCompatActivity {
TextView placeholder;
TextView placeholder2;
String balance;
Button editBalance;
Button addTrans;
Button viewAct;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_homepage2);

    editBalance = findViewById(R.id.editBalanceBtn);
    addTrans = findViewById(R.id.addTransBtn);
    viewAct = findViewById(R.id.viewActivity);

    //go to edit balance activity
    editBalance.setOnClickListener( new View.OnClickListener() {
        public void onClick(View view) {
           Intent goToEditBalance = new Intent(getApplicationContext(), EditBalance.class);
           startActivity(goToEditBalance);
        }
    });


    //go to add transaction activity
    addTrans.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            Intent goToAddTrans = new Intent(getApplicationContext(), AddTransaction.class);
            startActivity(goToAddTrans);
        }
    });

    //go to view trans activity
    viewAct.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            Intent goToViewTrans = new Intent(getApplicationContext(), ViewTransactions.class);
            startActivity(goToViewTrans);
        }
    });

    //changing balance
    placeholder = findViewById(R.id.balanceTextView);
    balance = getIntent().getExtras().getString("UserInput");
    placeholder.setText(balance);

    //changing balance bc of transactions
    //placeholder2 = findViewById(R.id.balanceTextView);
    //balance = getIntent().getExtras().getString("UserInput2");
    //placeholder2.setText(balance);


    }
}

这是我遇到问题的交易类。我很确定问题就在这里，我只是不确定怎么了。我从主页上单击了其他按钮，这些按钮可以正常工作，只是每个按钮由于某种原因而崩溃。

package com.example.natpc.moneymanager;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import java.util.ArrayList;

public class AddTransaction extends AppCompatActivity {
Button addTransBtn;
ArrayList<String> transactions;
EditText trans;
String transStr;
int newBalanceInt;
int transInt;
String newBalanceStr;
final EditBalance subtract = new EditBalance();

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_add_transaction);

    trans =  (EditText) findViewById(R.id.transEditText);

    transStr = trans.getText().toString();
    transInt = Integer.parseInt(transStr);
    newBalanceInt = subtract.getBalance() - transInt;
    newBalanceStr = Integer.toString(newBalanceInt);

    addTransBtn.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            Intent addTrans = new Intent(AddTransaction.this, 
homepage.class);

            addTrans.putExtra("UserInput2", newBalanceStr);
            startActivity(addTrans);
        }
    });
}
}

单击应用程序“已停止”（Android Studio）

0 个答案: