Activity生命周期与跳转

Activity生命周期与跳转

新建activity

新建ChattingActivity,用作聊天对象的展示页面

   

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 参数传递

public class ChattingActivity extends AppCompatActivity {

    private ActivityChattingBinding binding;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_chatting);
        binding = ActivityChattingBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
        TextView title = findViewById(R.id.title);
        Intent intent = getIntent();
        String str_title = intent.getStringExtra("title");
        title.setText(str_title);
    }

获取参数

创建intent对象，使用getStringExtra获取参数

参数绑定

使用findViewById获取TextView对象，使用setText绑定参数

页面跳转

    private void initRecyclerView() {
        mCollectRecyclerView=binding.chatRecyclerView;
        mCollectRecyclerAdapter = new myAdapter(getActivity(), chatEntities);
        //给RecyclerView设置adapter
        mCollectRecyclerView.setAdapter(mCollectRecyclerAdapter);
        //设置layoutManager,可以设置显示效果，是线性布局、grid布局，还是瀑布流布局
        //参数是：上下文、列表方向（横向还是纵向）、是否倒叙
        mCollectRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false));
        //设置item的分割线
        mCollectRecyclerView.addItemDecoration(new DividerItemDecoration(getActivity(),DividerItemDecoration.VERTICAL));
        //RecyclerView中没有item的监听事件，需要自己在适配器中写一个监听事件的接口。参数根据自定义
        mCollectRecyclerAdapter.setOnItemClickListener(new myAdapter.OnItemClickListener() {
            @Override
            public void OnItemClick(View view, ChatEntity data) {
                //此处进行监听事件的业务处理
                Toast.makeText(getActivity(),"你点击了我的消息",Toast.LENGTH_SHORT).show();
                Intent intent=new Intent();
                String title = data.getChatName();
                intent.putExtra("title",title);
                intent.setClass(getActivity(), ChattingActivity.class);
                getActivity().startActivity(intent);
            }
        });
    }

点击事件监听

RecyclerView中没有item的监听事件，需要自己在适配器中写一个监听事件的接口。参数根据自定义
在OnItemClick里面写入点击事件

 页面跳转

依然是新建Intent对象

通过setClass()设置将要跳转的页面

startActivity实现页面跳转，开启ChattingActivity页面生命周期

参数传递

通过intent对象putExtra()传递参数

这里使用"title"作为key

如果需要传递多个参数，可以使用多个putExtra

实现Activity无跳转传参

效果

点击悬浮球，Toast打印ResultActivity传递过来的参数

 

 

 "你收藏了本对话"为ResultActivity传递过来的参数

ResultActivity

public class ResultActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_result);
        Intent intent = getIntent();
        intent.putExtra("result", "你收藏了本对话");
        setResult(2, intent);
        finish();
    }
}

ChattingActivity接受参数

重写FloatingActionButton点击事件

FloatingActionButton floatingActionButton = findViewById(R.id.floatingActionButton);
        floatingActionButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent1 = new Intent(ChattingActivity.this, ResultActivity.class);
                test.launch(intent1);
            }
        });

ActivityResultLauncher

    public ActivityResultLauncher<Intent> test = registerForActivityResult(
            new ActivityResultContracts.StartActivityForResult(),
            new ActivityResultCallback<ActivityResult>() {
                @Override
                public void onActivityResult(ActivityResult result) {
                    if (result.getResultCode() == 2){

                        FloatingActionButton floatingActionButton = findViewById(R.id.floatingActionButton);
                        floatingActionButton.setBackgroundColor(Color.parseColor("#DAB649"));
                        String notice = result.getData().getStringExtra("result");
                        Toast.makeText(ChattingActivity.this,notice,Toast.LENGTH_SHORT).show();
                    }
                }
            }
    );

 

代码仓库

https://github.com/yoyo-sanchez/yoyo/tree/main/Wechat3