android - 变量不从 null 改变

Question

我的程序应该将 bname 更改为位置，但由于某种原因我不会将位置发送到 Record Expeance 这个 waycase R.id.record_expeance：

    startActivity(new Intent(BudgetStart.this, RecordExpeance.class));
    ex.changeName(position);
    BudgetStart.this.finish();
    break; 

之后应该等于位置，但它仍然是空的

package budget.app;


import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class RecordExpeance extends Activity implements OnClickListener
{    
    private String bname;
    protected void onCreate(Bundle savedInstanceState) 
    {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.recordexpeance);
        final BudgetDB entry = new BudgetDB(RecordExpeance.this);
        EditText a =(EditText)findViewById(R.id.txtExpeance);
        EditText b =(EditText)findViewById(R.id.txtEMomo);
        TextView c =(TextView)findViewById(R.id.lblBudgetAmount);
        TextView d =(TextView)findViewById(R.id.lblBudgetName);
       d.setText(bname);

        String bamount;

        entry.open();
        bamount = entry.getBamount(bname);
        entry.close();

        Button A = (Button)findViewById(R.id.btnFinish);

        A.setOnClickListener(this);
    }

    public void onClick(View argo) 
    {
        // TODO Auto-generated method stub
        startActivity(new Intent(RecordExpeance.this, BudgetStart.class));
        RecordExpeance.this.finish();
    }
    public void changeName(String position) 
    {
        // TODO Auto-generated method stub

        bname = position;
    }
}

Answer 1

position传递Intent会更容易：

Intent intent = new Intent(BudgetStart.this, RecordExpeance.class);
intent.putExtra("position", position);
startActivity(intent);
BudgetStart.this.finish();
break; 

然后从 Intent 中读取它RecordExpeance：

super.onCreate(savedInstanceState);
setContentView(R.layout.recordexpeance);

bname = getIntent().getIntExtra("position", 1); 
// Where 1 is the default value if you forgot use putExtra()