Android Studio second job

Work requirements:

1. Please realize the understanding of the Activity life cycle according to the course content, and use the log to display the state changes of the life cycle;

2. According to the content of the blog: https://www.jianshu.com/p/c4cfe38a91ed ("click" in the advanced chapter), the single-click function of the list item is added on the basis of the previous homework. The specific requirements are: Create a new activity1, click on an item of recycleview to jump to this new activity1. For example: clicking on the news list will jump to the news details page;

3. To implement the latest activityforresult function, the specific requirements are as follows: Create a new activity2, add a button on activity1 to receive the return value of activity2. For example: Click the favorite button on the news details page to display the current number of favorites as N.

contents of homework:

ResultActivity.java code:

package com.example.work2;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;

import java.util.Calendar;

public class ResultActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_result);
        Intent intent=getIntent();
        intent.putExtra("data","今天是安卓课程，老师是肖蓉。\n"+"上课的时间是："+ Calendar.getInstance().getTime());

        setResult(888,intent);
        finish();
    }
}

activity_item.xml code:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ItemActivity">

    <TextView
        android:id="@+id/itemtextView2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="32dp"
        android:layout_marginEnd="32dp"
        android:text="这是返回的信息"
        android:textSize="30sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.441"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.772" />

    <TextView
        android:id="@+id/itemtextView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="这是详情页面"
        android:textSize="30sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.529"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.153" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="查看课程信息"
        android:textSize="30sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/itemtextView1"
        app:layout_constraintVertical_bias="0.083" />

</androidx.constraintlayout.widget.ConstraintLayout>

 ItemActivity.java code:

package com.example.work2;

import androidx.activity.result.ActivityResult;
import androidx.activity.result.ActivityResultCallback;
import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class ItemActivity extends AppCompatActivity {
    private Button button;
    private TextView textView;

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

        textView=findViewById(R.id.itemtextView2);

        button=findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                Intent intent=new Intent(ItemActivity.this,ResultActivity.class);

                test.launch(intent);

            }
        });

    }

    public ActivityResultLauncher test;
    {
        test = registerForActivityResult(
                new ActivityResultContracts.StartActivityForResult(),
                new ActivityResultCallback<ActivityResult>() {

                    @Override
                    public void onActivityResult(ActivityResult result) {
                        if (result.getResultCode() == 888) {
                            Log.d("xr", "onActivityResultLauncher...");
                            textView.setText(result.getData().getStringExtra("data"));
                        }
                    }
                });
    }
}

 

Source Code Warehouse: Work2 Ming/android - Code Cloud - Open Source China (gitee.com)