5.25作业

//mainActivity
package com.hanqi.myapplication;

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

public class Test2 extends AppCompatActivity {
    EditText et_1;
    EditText et_2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test2);
        et_1=(EditText)findViewById(R.id.et_1);
        et_2=(EditText)findViewById(R.id.et_2);
    }
    public void bt2_OnClick(View v){
        Intent intent=new Intent(this,zhuce.class);
        startActivityForResult(intent,1);

    }
    String username;
    String password;
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        username=data.getStringExtra("username");
        password=data.getStringExtra("password");
        et_1.setText(username);
        et_2.setText(password);
    }
}

//zhuce界面
package com.hanqi.myapplication;

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

public class zhuce extends AppCompatActivity {
         EditText et_3;
    EditText et_4;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_zhuce);
        et_3=(EditText)findViewById(R.id.et_3);
        et_4=(EditText)findViewById(R.id.et_4);
    }

    public  void bt3_OnClick(View v){
        final String str1=et_3.getText().toString();
        final String str2=et_4.getText().toString();
        SharedPreferences sharedPreferences=getSharedPreferences("abc",MODE_APPEND);
        SharedPreferences.Editor editor=sharedPreferences.edit();
        editor.putString("a", str1);
        editor.putString("b", str2);
        editor.commit();
        Intent intent=new Intent(this,Test2.class);
        String str3=sharedPreferences.getString("a", null);
        String str4=sharedPreferences.getString("b", null);

        intent.putExtra("username",str3);

        intent.putExtra("password",str4);
        setResult(RESULT_OK,intent);
        finish();
    }
}