安卓第五周作业

package com.example.myapplication;

import androidx.activity.result.ActivityResult;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;


public class MainActivity extends AppCompatActivity implements View.onClickListener {
    private EditText username;
    private  EditText password;

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

        Button button = (Button) findViewById(R.id.button2);    //注册按钮
        button.setonClickListener(this);
        username = (EditText) findViewById(R.id.username);       //注册用户名的输入框
        password = (EditText) findViewById(R.id.password);    //注册密码输入框

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode,  Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode) {
            case 1:
                if (resultCode == RESULT_OK) {
                    String Data = data.getStringExtra("extra_name");
                    username.setText(Data);
                }
                break;

        }
    }



    @Override                                  //重写点击按钮时，触发的动作
    public void onClick(View v){
        switch (v.getId()){       //得到被点击按钮的id号
            case R.id.button2:     //如果得到的id号是“登录按钮”的id号 就执行下面语句
                String usernameText = username.getText().toString();           //创建usernameText字符串用于保存输入的用户名
                String passwordText = password.getText().toString();           //创建passwordText字符串用于保存输入的密码
                Intent intent = new Intent(MainActivity.this,MainActivity2.class);
                intent.putExtra("extra_name",usernameText);
                intent.putExtra("extra_pass",passwordText);
                startActivityForResult(intent,1);
                break;
            default:
                break;
        }
    }
}

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity2 extends AppCompatActivity implements View.onClickListener {
    private EditText username2;
    private EditText password2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        Intent intent = getIntent();
        String name = intent.getStringExtra("extra_name");
        String pass = intent.getStringExtra("extra_pass");

        Button button = (Button) findViewById(R.id.button4);    //注册按钮
        button.setonClickListener(this);
        username2 = (EditText) findViewById(R.id.username);       //注册用户名的输入框
        password2 = (EditText) findViewById(R.id.password);    //注册密码输入框
        username2.setText(name);
        password2.setText(pass);

    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {       //得到被点击按钮的id号
            case R.id.button4:
                String usernameText = username2.getText().toString();           //创建usernameText字符串用于保存输入的用户名
                Intent intent2 = new Intent();
                intent2.putExtra("extra_name",usernameText);
                setResult(RESULT_OK,intent2);
                finish();
                break;

            default:

        }
    }
}

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新建Activity.java

在layout里新建xml布局文件