2024.5.10

第四十五天

所花时间：2小时

代码量：100+

博客量：1

了解到的知识点：大作业1

Mainactivity.java

package com.example.photo1;

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

import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private EditText editTextPost;
    private RecyclerView recyclerViewSelectedImages, recyclerViewPosts;
    private List<Uri> imageUris = new ArrayList<>();
    private List<Post> posts = new ArrayList<>(); 
    private ImageAdapter imageAdapter;
    private PostAdapter postAdapter;

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

        editTextPost = findViewById(R.id.editTextPost);
        Button buttonSelectImages = findViewById(R.id.buttonSelectImages);
        Button buttonUploadPost = findViewById(R.id.buttonUploadPost);
        recyclerViewSelectedImages = findViewById(R.id.recyclerViewSelectedImages);
        recyclerViewPosts = findViewById(R.id.recyclerViewPosts);

        // Setup RecyclerView for selected images
        recyclerViewSelectedImages.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));
        imageAdapter = new ImageAdapter(imageUris, this);
        recyclerViewSelectedImages.setAdapter(imageAdapter);

        // Setup RecyclerView for posts
        recyclerViewPosts.setLayoutManager(new LinearLayoutManager(this));
        postAdapter = new PostAdapter(posts, this);
        recyclerViewPosts.setAdapter(postAdapter);

        // Image selection launcher
        ActivityResultLauncher<String[]> imagePickerLauncher = registerForActivityResult(
                new ActivityResultContracts.OpenMultipleDocuments(),
                uris -> {
                    if (uris != null && !uris.isEmpty()) {
                        imageUris.clear();
                        imageUris.addAll(uris);
                        imageAdapter.notifyDataSetChanged();
                    }
                });

        // Select images button event
        buttonSelectImages.setOnClickListener(v -> imagePickerLauncher.launch(new String[]{"image/*"}));

        // Upload post button event
        buttonUploadPost.setOnClickListener(v -> uploadPost());
    }

    private void uploadPost() {
        String postText = editTextPost.getText().toString().trim();
        if (!postText.isEmpty() || !imageUris.isEmpty()) {
            Post newPost = new Post(postText, new ArrayList<>(imageUris));
            posts.add(newPost);
            postAdapter.notifyDataSetChanged();
            editTextPost.setText("");
            imageUris.clear();
            imageAdapter.notifyDataSetChanged();

            Toast.makeText(this, "发表成功!", Toast.LENGTH_SHORT).show();
        } else {
            Toast.makeText(this, "请输入文字内容或插入图片！", Toast.LENGTH_SHORT).show();
        }
    }
}