Compose——下拉刷新、上拉加载更多

效果图：

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主要的代码为：

package com.yaona.compose_list_shangla.swipe

import androidx.compose.foundation.Image
import androidx.compose.foundation.layout.*
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.LazyListScope
import androidx.compose.foundation.lazy.rememberLazyListState
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.ButtonDefaults.elevation
import androidx.compose.material.ButtonDefaults.textButtonColors
import androidx.compose.material.CircularProgressIndicator
import androidx.compose.material.Text
import androidx.compose.material.TextButton
import androidx.compose.runtime.Composable
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.res.painterResource
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import androidx.paging.LoadState
import androidx.paging.compose.LazyPagingItems
import com.google.accompanist.swiperefresh.SwipeRefresh
import com.google.accompanist.swiperefresh.rememberSwipeRefreshState
import com.yaona.compose_list_shangla.ui.theme.gray300
import com.yaona.compose_list_shangla.ui.theme.gray600
import com.yaona.compose_list_shangla.ui.theme.gray700
import kotlinx.coroutines.launch
import com.yaona.compose_list_shangla.R

/**
 * 下拉刷新，上拉加载view的封装
 *
 * implementation "com.google.accompanist:accompanist-swiperefresh:xxx"
 * */
@Composable
fun <T : Any> SwipeRefreshList(
    collectAsLazyPagingItems: LazyPagingItems<T>,
    listContent: LazyListScope.() -> Unit,
) {
    val rememberSwipeRefreshState = rememberSwipeRefreshState(isRefreshing = false)

    SwipeRefresh(
        state = rememberSwipeRefreshState,
        onRefresh = { collectAsLazyPagingItems.refresh() }
    ) {
        val lazyListState = rememberLazyListState()

        val coroutineScope = rememberCoroutineScope()

        rememberSwipeRefreshState.isRefreshing =
            collectAsLazyPagingItems.loadState.refresh is LoadState.Loading

        LazyColumn(
            state = lazyListState,
            modifier = Modifier
                .fillMaxWidth()
                .fillMaxHeight(),

            ) {
            listContent()
            collectAsLazyPagingItems.apply {
                when {
                    loadState.append is LoadState.Loading -> {
                        //加载更多，底部loading
                        item { LoadingItem() }
                    }
                    loadState.append is LoadState.Error -> {
                        //加载更多异常
                        item {
                            ErrorMoreRetryItem() {
                                collectAsLazyPagingItems.retry()
                            }
                        }
                    }

                    loadState.append == LoadState.NotLoading(endOfPaginationReached = true) -> {
                        // 已经没有更多数据了
                        item {
                            NoMoreDataFindItem(onClick = {
                                coroutineScope.launch {
                                    lazyListState.animateScrollToItem(0)
                                }
                            })
                        }
                    }

                    loadState.refresh is LoadState.Error -> {
                        if (collectAsLazyPagingItems.itemCount <= 0) {
                            //刷新的时候，如果itemCount小于0，第一次加载异常
                            item {
                                ErrorContent() {
                                    collectAsLazyPagingItems.retry()
                                }
                            }
                        } else {
                            item {
                                ErrorMoreRetryItem() {
                                    collectAsLazyPagingItems.retry()
                                }
                            }
                        }
                    }
                    loadState.refresh is LoadState.Loading -> {
                        // 第一次加载且正在加载中
                        if (collectAsLazyPagingItems.itemCount == 0) {
                        }
                    }
                }
            }
        }
    }
}

/**
 * 底部加载更多失败处理
 * */
@Composable
fun ErrorMoreRetryItem(retry: () -> Unit) {
    Box(modifier = Modifier.fillMaxWidth(), contentAlignment = Alignment.Center) {
        TextButton(
            onClick = { retry() },
            modifier = Modifier
                .padding(20.dp)
                .width(80.dp)
                .height(30.dp),
            shape = RoundedCornerShape(6.dp),
            contentPadding = PaddingValues(3.dp),
            colors = textButtonColors(backgroundColor = gray300),
            elevation = elevation(
                defaultElevation = 2.dp,
                pressedElevation = 4.dp,
            ),
        ) {
            Text(text = "请重试", color = gray600)
        }
    }
}

@Composable
fun NoMoreDataFindItem(onClick: () -> Unit) {
    Box(modifier = Modifier.fillMaxWidth(), contentAlignment = Alignment.Center) {
        TextButton(
            onClick = { onClick() },
            modifier = Modifier
                .padding(20.dp)
                .width(80.dp)
                .height(30.dp),
            shape = RoundedCornerShape(6.dp),
            contentPadding = PaddingValues(3.dp),
            colors = textButtonColors(backgroundColor = gray300),
            elevation = elevation(
                defaultElevation = 2.dp,
                pressedElevation = 4.dp,
            ),
        ) {
            Text(text = "已经没有更多数据啦 ~~ Click to top", color = gray600)
        }
    }
}

/**
 * 页面加载失败处理
 * */
@Composable
fun ErrorContent(retry: () -> Unit) {
    Column(
        modifier = Modifier
            .fillMaxSize()
            .padding(top = 100.dp),
        verticalArrangement = Arrangement.Center,
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        Image(
            modifier = Modifier.padding(top = 80.dp),
            painter = painterResource(id = R.drawable.ic_default_empty),
            contentDescription = null
        )
        Text(text = "请求失败，请检查网络", modifier = Modifier.padding(8.dp))
        TextButton(
            onClick = { retry() },
            modifier = Modifier
                .padding(20.dp)
                .width(80.dp)
                .height(30.dp),
            shape = RoundedCornerShape(10.dp),
            contentPadding = PaddingValues(5.dp),
            colors = textButtonColors(backgroundColor = gray300),
            elevation = elevation(
                defaultElevation = 2.dp,
                pressedElevation = 4.dp,
            )
            //colors = ButtonDefaults
        ) { Text(text = "重试", color = gray700) }
    }
}

/**
 * 底部加载更多正在加载中...
 * */
@Composable
fun LoadingItem() {
    Row(
        modifier = Modifier
            .height(34.dp)
            .fillMaxWidth()
            .padding(5.dp),
        horizontalArrangement = Arrangement.Center
    ) {
        CircularProgressIndicator(
            modifier = Modifier
                .size(24.dp),
            color = gray600,
            strokeWidth = 2.dp
        )
        Text(
            text = "加载中...",
            color = gray600,
            modifier = Modifier
                .fillMaxHeight()
                .padding(start = 20.dp),
            fontSize = 18.sp,
        )
    }
}

整体的代码下载地址为：https://download.csdn.net/download/wy313622821/88646806