在Java Fragment中集成与控制Jetpack Compose对话框

<!-- fragment_main.xml -->
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- 其他传统视图组件，例如一个用于触发对话框的按钮 -->
    <Button
        android:id="@+id/show_dialog_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="显示Compose对话框"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent" />

    <!-- 用于托管Compose对话框的隐式ComposeView -->
    <androidx.compose.ui.platform.ComposeView
        android:id="@+id/compose_dialog_host"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

// MyViewModel.java
package com.example.yourapp; // 替换为你的包名

import androidx.lifecycle.LiveData;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;

public class MyViewModel extends ViewModel {
    // 用于控制Compose对话框可见性的MutableLiveData
    private final MutableLiveData<Boolean> _showComposeDialog = new MutableLiveData<>(false);
    public LiveData<Boolean> showComposeDialog = _showComposeDialog; // 对外暴露为不可变的LiveData

    // 提供一个公共方法来更新对话框的显示状态
    public void setShowDialog(boolean show) {
        _showComposeDialog.setValue(show);
    }
}

// MyFragment.java
package com.example.yourapp; // 替换为你的包名

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.compose.ui.platform.ComposeView;
import androidx.compose.ui.platform.ViewCompositionStrategy;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProvider;

// 导入Compose相关依赖，确保已在build.gradle中添加
// implementation "androidx.compose.ui:ui-tooling-preview"
// implementation "androidx.compose.material:material"
// implementation "androidx.compose.runtime:runtime-livedata" // 用于LiveData在Compose中的观察

public class MyFragment extends Fragment {

    private MyViewModel viewModel;
    private static final int YOUR_REQUEST_CODE = 1001; // 示例请求码

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 初始化ViewModel
        viewModel = new ViewModelProvider(this).get(MyViewModel.class);
    }

    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_main, container, false);
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        // 查找布局中的ComposeView
        ComposeView composeDialogHost = view.findViewById(R.id.compose_dialog_host);
        // 设置ComposeView的组合策略，确保Compose内容跟随视图生命周期正确销毁
        composeDialogHost.setViewCompositionStrategy(ViewCompositionStrategy.DisposeOnViewTreeLifecycleDestroyed);

        // 设置ComposeView的内容
        composeDialogHost.setContent(() -> {
            // 使用observeAsState观察ViewModel中的LiveData，并在状态变化时触发Compose重组
            // 注意：AlertDialog、Text等是Kotlin Compose函数，在此处以Kotlin DSL语法编写
            // 确保你已添加 "androidx.compose.runtime:runtime-livedata" 依赖
            boolean showDialog = viewModel.showComposeDialog.observeAsState(false).getValue();

            if (