feat: in-app update check + download + install

Auto-check GitHub Releases latest on launch (24h throttle), show an
update banner on the home screen, download the APK in-app with progress,
and trigger the system installer via FileProvider + REQUEST_INSTALL_PACKAGES.

- core/UpdateChecker: fetch releases/latest, semver compare, stream APK
  to externalFilesDir, install via FileProvider (handles MIUI unknown-sources).
- SettingsStore: updateCheckEnabled / lastUpdateCheckTime / ignoredVersion.
- HomeScreen: update banner + UpdateDialog.
- SettingsScreen: "关于与更新" card with auto-check toggle and manual check.
- manifest: REQUEST_INSTALL_PACKAGES + FileProvider; new res/xml/file_paths.xml.
- version 1.4.2 -> 1.5.0 (versionCode 7 -> 8).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -23,6 +23,7 @@
   - 余额 ≤5 条自动停用，下次打开 App 提醒
   - 每 5 分钟最多发 1 条，避免刷屏
   - 自动解析失败时回退手动额度计数
+- **应用内更新**：每天自动检查 GitHub 新版本，发现新版后一键下载并通过系统安装器升级，无需手动去网页下载。
 
 ## 快速开始
 

app/build.gradle.kts

@@ -13,8 +13,8 @@ android {
         applicationId = "com.a2i.forwarder"
         minSdk = 34
         targetSdk = 36
-        versionCode = 7
+        versionCode = 8
-        versionName = "1.4.2"
+        versionName = "1.5.0"
     }
 
     signingConfigs {

app/src/main/AndroidManifest.xml

@@ -11,6 +11,7 @@
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
 
     <application
         android:name=".A2iApp"
@@ -45,5 +46,15 @@
             </intent-filter>
         </service>
 
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="${applicationId}.fileprovider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/file_paths" />
+        </provider>
+
     </application>
 </manifest>

app/src/main/java/com/a2i/forwarder/A2iApp.kt

@@ -7,6 +7,7 @@ import com.a2i.forwarder.core.ConnectivityMonitor
 import com.a2i.forwarder.core.LogStore
 import com.a2i.forwarder.core.PhoneCallMonitor
 import com.a2i.forwarder.core.SmsFallbackForwarder
+import com.a2i.forwarder.core.UpdateChecker
 import com.a2i.forwarder.store.AppRulesStore
 import com.a2i.forwarder.store.SettingsStore
 import kotlinx.coroutines.CoroutineScope
@@ -30,6 +31,8 @@ class A2iApp : Application() {
         private set
     lateinit var smsForwarder: SmsFallbackForwarder
         private set
+    lateinit var updateChecker: UpdateChecker
+        private set
 
     override fun onCreate() {
         super.onCreate()
@@ -43,6 +46,8 @@ class A2iApp : Application() {
         connectivityMonitor.start()
         carrierBalanceQuery = CarrierBalanceQuery(this)
         smsForwarder = SmsFallbackForwarder(this)
+        updateChecker = UpdateChecker(this)
+        updateChecker.start()
     }
 
     companion object {

app/src/main/java/com/a2i/forwarder/core/UpdateChecker.kt

@@ -0,0 +1,192 @@
+package com.a2i.forwarder.core
+
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
+import android.provider.Settings
+import androidx.core.content.FileProvider
+import com.a2i.forwarder.A2iApp
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import okhttp3.OkHttpClient
+import okhttp3.Request
+import org.json.JSONObject
+import java.io.File
+import java.util.concurrent.TimeUnit
+
+data class UpdateInfo(
+    val latestVersion: String,
+    val apkUrl: String,
+    val apkSize: Long,
+    val releaseNotes: String,
+    val releasePageUrl: String,
+)
+
+/**
+ * 应用内更新：拉取 GitHub Releases 最新版 → 版本比较 → 下载 APK → 调起系统安装器。
+ * Android targetSdk≥24 须用 FileProvider，targetSdk≥26 安装未知来源 APK 须 REQUEST_INSTALL_PACKAGES。
+ */
+class UpdateChecker(private val context: Context) {
+    private val app get() = A2iApp.instance
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+    private val http = OkHttpClient.Builder()
+        .connectTimeout(10, TimeUnit.SECONDS)
+        .readTimeout(30, TimeUnit.SECONDS)
+        .retryOnConnectionFailure(true)
+        .build()
+
+    val updateInfo = MutableStateFlow<UpdateInfo?>(null)
+    val downloading = MutableStateFlow(false)
+    val downloadProgress = MutableStateFlow(0)        // 0..100
+    val lastError = MutableStateFlow<String?>(null)
+
+    fun start() {
+        scope.launch { check(force = false) }
+    }
+
+    suspend fun check(force: Boolean): Result<UpdateInfo?> = withContext(Dispatchers.IO) {
+        runCatching {
+            val settings = app.settings
+            val now = System.currentTimeMillis()
+            if (!force) {
+                // 自动检查被关闭或未满 24h：保持现状，不发请求
+                if (!settings.updateCheckEnabled.value) return@runCatching updateInfo.value
+                if (now - settings.lastUpdateCheckTime.value < CHECK_INTERVAL_MS) return@runCatching updateInfo.value
+            }
+            val req = Request.Builder()
+                .url(RELEASES_API)
+                .header("Accept", "application/vnd.github+json")
+                .header("User-Agent", "a2i-android")
+                .get()
+                .build()
+            val info = http.newCall(req).execute().use { res ->
+                if (!res.isSuccessful) error("HTTP ${res.code}")
+                val body = res.body?.string() ?: error("空响应")
+                parseRelease(body)
+            }
+            settings.setLastUpdateCheck(now)
+            val current = currentVersionName()
+            val available = info != null &&
+                isNewer(info.latestVersion, current) &&
+                info.latestVersion != settings.ignoredVersion.value
+            updateInfo.value = if (available) info else null
+            lastError.value = null
+            updateInfo.value
+        }.onFailure { lastError.value = it.message ?: "检查失败" }
+    }
+
+    private fun parseRelease(body: String): UpdateInfo? {
+        val json = JSONObject(body)
+        val tag = json.optString("tag_name").removePrefix("v").trim()
+        if (tag.isEmpty()) return null
+        val assets = json.optJSONArray("assets") ?: return null
+        var apkUrl = ""
+        var apkSize = 0L
+        for (i in 0 until assets.length()) {
+            val a = assets.optJSONObject(i) ?: continue
+            if (a.optString("name").endsWith(".apk", ignoreCase = true)) {
+                apkUrl = a.optString("browser_download_url")
+                apkSize = a.optLong("size")
+                break
+            }
+        }
+        if (apkUrl.isEmpty()) return null
+        return UpdateInfo(
+            latestVersion = tag,
+            apkUrl = apkUrl,
+            apkSize = apkSize,
+            releaseNotes = json.optString("body").orEmpty(),
+            releasePageUrl = json.optString("html_url").orEmpty(),
+        )
+    }
+
+    suspend fun download(info: UpdateInfo): File? = withContext(Dispatchers.IO) {
+        downloading.value = true
+        downloadProgress.value = 0
+        lastError.value = null
+        try {
+            val req = Request.Builder().url(info.apkUrl).get().build()
+            http.newCall(req).execute().use { res ->
+                if (!res.isSuccessful) { lastError.value = "HTTP ${res.code}"; return@use null }
+                val body = res.body ?: run { lastError.value = "空响应"; return@use null }
+                val total = body.contentLength()
+                val dir = context.getExternalFilesDir(null) ?: context.cacheDir
+                val target = File(dir, "a2i-${info.latestVersion}.apk")
+                target.outputStream().use { sink ->
+                    val input = body.byteStream()
+                    val buf = ByteArray(8 * 1024)
+                    var read = 0L
+                    while (true) {
+                        val n = input.read(buf)
+                        if (n <= 0) break
+                        sink.write(buf, 0, n)
+                        read += n
+                        if (total > 0) downloadProgress.value = (read * 100 / total).toInt()
+                    }
+                }
+                downloadProgress.value = 100
+                target
+            }
+        } catch (e: Exception) {
+            lastError.value = e.message ?: "下载失败"
+            null
+        } finally {
+            downloading.value = false
+        }
+    }
+
+    fun install(apk: File) {
+        // 国产 ROM 需用户先在系统设置开启「安装未知应用」
+        if (!context.packageManager.canRequestPackageInstalls()) {
+            val intent = Intent(Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES).apply {
+                data = Uri.parse("package:${context.packageName}")
+                addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+            }
+            runCatching { context.startActivity(intent) }
+            return
+        }
+        val uri = FileProvider.getUriForFile(context, "${context.packageName}.fileprovider", apk)
+        val intent = Intent(Intent.ACTION_VIEW).apply {
+            setDataAndType(uri, "application/vnd.android.package-archive")
+            addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+            addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+        }
+        runCatching { context.startActivity(intent) }
+    }
+
+    fun ignoreVersion(v: String) {
+        scope.launch {
+            app.settings.setIgnoredVersion(v)
+            updateInfo.value = null
+        }
+    }
+
+    private fun currentVersionName(): String {
+        return runCatching {
+            @Suppress("DEPRECATION")
+            context.packageManager.getPackageInfo(context.packageName, 0).versionName ?: "0"
+        }.getOrDefault("0")
+    }
+
+    /** 语义版本比较：按 "." 分段逐段比，段数不等时短的补 0。 */
+    fun isNewer(latest: String, current: String): Boolean {
+        val l = latest.split(".").map { it.substringBefore("-").toIntOrNull() ?: 0 }
+        val c = current.split(".").map { it.substringBefore("-").toIntOrNull() ?: 0 }
+        val n = maxOf(l.size, c.size)
+        for (i in 0 until n) {
+            val lv = l.getOrElse(i) { 0 }
+            val cv = c.getOrElse(i) { 0 }
+            if (lv != cv) return lv > cv
+        }
+        return false
+    }
+
+    companion object {
+        const val RELEASES_API = "https://api.github.com/repos/lsxf/a2i/releases/latest"
+        const val CHECK_INTERVAL_MS = 24L * 60 * 60 * 1000
+    }
+}

app/src/main/java/com/a2i/forwarder/store/SettingsStore.kt

@@ -47,6 +47,10 @@ class SettingsStore(
         val SMS_BALANCE = intPreferencesKey("sms_balance")
         val SMS_SUSPENDED = booleanPreferencesKey("sms_suspended")
         val SMS_LAST_SENT = longPreferencesKey("sms_last_sent")
+        // 应用更新
+        val UPDATE_CHECK_AUTO = booleanPreferencesKey("update_check_auto")
+        val LAST_UPDATE_CHECK = longPreferencesKey("last_update_check")
+        val IGNORED_VERSION = stringPreferencesKey("ignored_version")
     }
 
     private val defaultServers = listOf(
@@ -76,6 +80,11 @@ class SettingsStore(
     val smsSuspended = MutableStateFlow(false)       // 余额 ≤5 自动挂起
     val lastSmsSentTime = MutableStateFlow(0L)       // 限频时间戳
 
+    // 应用更新
+    val updateCheckEnabled = MutableStateFlow(true)     // 自动检查更新开关
+    val lastUpdateCheckTime = MutableStateFlow(0L)      // 上次检查时间戳
+    val ignoredVersion = MutableStateFlow("")           // 用户忽略的版本号
+
     init {
         scope.launch {
             ds.data.collect { p ->
@@ -102,6 +111,10 @@ class SettingsStore(
                 smsBalance.value = p[K.SMS_BALANCE] ?: -1
                 smsSuspended.value = p[K.SMS_SUSPENDED] ?: false
                 lastSmsSentTime.value = p[K.SMS_LAST_SENT] ?: 0L
+                // 应用更新
+                updateCheckEnabled.value = p[K.UPDATE_CHECK_AUTO] ?: true
+                lastUpdateCheckTime.value = p[K.LAST_UPDATE_CHECK] ?: 0L
+                ignoredVersion.value = p[K.IGNORED_VERSION] ?: ""
             }
         }
     }
@@ -163,6 +176,10 @@ class SettingsStore(
     suspend fun setSmsSuspended(v: Boolean) { edit { it[K.SMS_SUSPENDED] = v }; smsSuspended.value = v }
     suspend fun setLastSmsSentTime(v: Long) { edit { it[K.SMS_LAST_SENT] = v }; lastSmsSentTime.value = v }
 
+    suspend fun setUpdateCheckEnabled(v: Boolean) { edit { it[K.UPDATE_CHECK_AUTO] = v }; updateCheckEnabled.value = v }
+    suspend fun setLastUpdateCheck(v: Long) { edit { it[K.LAST_UPDATE_CHECK] = v }; lastUpdateCheckTime.value = v }
+    suspend fun setIgnoredVersion(v: String) { edit { it[K.IGNORED_VERSION] = v }; ignoredVersion.value = v }
+
     suspend fun snapshot() = ds.data.first()
 
     companion object {

app/src/main/java/com/a2i/forwarder/ui/screens/HomeScreen.kt

@@ -22,6 +22,7 @@ import androidx.compose.material.icons.filled.Notifications
 import androidx.compose.material.icons.filled.PowerSettingsNew
 import androidx.compose.material.icons.filled.Settings
 import androidx.compose.material.icons.filled.WarningAmber
+import androidx.compose.material.icons.filled.SystemUpdate
 import androidx.compose.material3.Button
 import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.Icon
@@ -66,6 +67,8 @@ fun HomeScreen(onOpenLog: () -> Unit, onOpenSettings: () -> Unit) {
     val filtered by app.logStore.filteredCount.collectAsState()
     val failed by app.logStore.failedCount.collectAsState()
     val smsSuspended by app.settings.smsSuspended.collectAsState()
+    val update by app.updateChecker.updateInfo.collectAsState()
+    var showUpdateDialog by remember { mutableStateOf(false) }
 
     var granted by remember { mutableStateOf(isNotificationListenerEnabled(context)) }
     val lifecycleOwner = LocalLifecycleOwner.current
@@ -90,6 +93,29 @@ fun HomeScreen(onOpenLog: () -> Unit, onOpenSettings: () -> Unit) {
             )
         }
 
+        val info = update
+        if (info != null) {
+            item {
+                SectionCard {
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        IconBox(icon = Icons.Filled.SystemUpdate, tint = MaterialTheme.colorScheme.primary)
+                        Spacer(Modifier.width(12.dp))
+                        Column(Modifier.weight(1f)) {
+                            Text("发现新版本 v${info.latestVersion}", style = MaterialTheme.typography.titleMedium)
+                            Text(
+                                "安装包 ${formatSize(info.apkSize)} · 点击立即更新",
+                                style = MaterialTheme.typography.bodySmall,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            )
+                        }
+                        StatusBadge(text = "新", tint = MaterialTheme.colorScheme.primary)
+                    }
+                    Spacer(Modifier.size(12.dp))
+                    Button(onClick = { showUpdateDialog = true }, modifier = Modifier.fillMaxWidth()) { Text("立即更新") }
+                }
+            }
+        }
+
         if (smsSuspended) {
             item {
                 SectionCard {
@@ -200,6 +226,11 @@ fun HomeScreen(onOpenLog: () -> Unit, onOpenSettings: () -> Unit) {
             )
         }
     }
+
+    if (showUpdateDialog) {
+        val info = update
+        if (info != null) UpdateDialog(info, onDismiss = { showUpdateDialog = false })
+    }
 }
 
 @Composable

app/src/main/java/com/a2i/forwarder/ui/screens/SettingsScreen.kt

@@ -26,6 +26,8 @@ import androidx.compose.material.icons.filled.Edit
 import androidx.compose.material.icons.filled.History
 import androidx.compose.material.icons.filled.RestartAlt
 import androidx.compose.material.icons.filled.Settings
+import androidx.compose.material.icons.filled.SystemUpdateAlt
+import androidx.compose.material.icons.filled.Update
 import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.Button
 import androidx.compose.material3.CircularProgressIndicator
@@ -60,6 +62,7 @@ import com.a2i.forwarder.model.BarkServer
 import com.a2i.forwarder.model.OFFICIAL_BARK_SERVER
 import com.a2i.forwarder.ui.ClickRow
 import com.a2i.forwarder.ui.ScreenTitle
+import com.a2i.forwarder.ui.appVersionName
 import com.a2i.forwarder.ui.SectionCard
 import com.a2i.forwarder.ui.StatusBadge
 import kotlinx.coroutines.launch
@@ -80,6 +83,12 @@ fun SettingsScreen(onOpenLog: () -> Unit) {
     var showAdd by remember { mutableStateOf(false) }
     var editing by remember { mutableStateOf<BarkServer?>(null) }
 
+    // 应用更新状态
+    val updateAuto by app.settings.updateCheckEnabled.collectAsState()
+    val updateInfo by app.updateChecker.updateInfo.collectAsState()
+    var checking by remember { mutableStateOf(false) }
+    var checkMsg by remember { mutableStateOf<String?>(null) }
+
     // 短信兜底状态
     val smsFallback by app.settings.smsFallbackEnabled.collectAsState()
     val smsTarget by app.settings.smsTargetNumber.collectAsState()
@@ -283,6 +292,56 @@ fun SettingsScreen(onOpenLog: () -> Unit) {
             }
         }
 
+        item {
+            SectionCard("关于与更新", subtitle = "版本检查（数据来自 GitHub Releases）") {
+                com.a2i.forwarder.ui.SwitchRow(
+                    title = "自动检查更新",
+                    subtitle = "启动时检查，且距上次满 24 小时再次检查",
+                    checked = updateAuto,
+                    icon = Icons.Filled.Update,
+                ) { v -> app.appScope.launch { app.settings.setUpdateCheckEnabled(v) } }
+
+                ClickRow(
+                    title = "检查更新",
+                    subtitle = "当前 v${appVersionName(context)}" +
+                        (updateInfo?.let { " · 已发现 v${it.latestVersion}" } ?: " · 点击立即检查"),
+                    icon = Icons.Filled.SystemUpdateAlt,
+                    onClick = {
+                        app.appScope.launch {
+                            checking = true
+                            checkMsg = null
+                            val r = app.updateChecker.check(force = true)
+                            checking = false
+                            checkMsg = when {
+                                !r.isSuccess -> "检查失败：${r.exceptionOrNull()?.message}"
+                                r.getOrNull() != null -> "发现新版本，请到首页更新"
+                                else -> "已是最新版本"
+                            }
+                        }
+                    },
+                )
+
+                if (checking) {
+                    Row(
+                        modifier = Modifier.fillMaxWidth().padding(vertical = 4.dp),
+                        verticalAlignment = Alignment.CenterVertically,
+                    ) {
+                        CircularProgressIndicator(Modifier.size(16.dp), strokeWidth = 2.dp)
+                        Spacer(Modifier.width(8.dp))
+                        Text("正在检查…", style = MaterialTheme.typography.bodySmall, color = MaterialTheme.colorScheme.onSurfaceVariant)
+                    }
+                }
+                checkMsg?.let {
+                    Text(
+                        it,
+                        style = MaterialTheme.typography.bodySmall,
+                        color = if (it.startsWith("已是")) MaterialTheme.colorScheme.tertiary else MaterialTheme.colorScheme.error,
+                        modifier = Modifier.padding(start = 50.dp, top = 2.dp, bottom = 4.dp),
+                    )
+                }
+            }
+        }
+
         item {
             SectionCard("维护", subtitle = "日志查看和本地统计清理") {
                 ClickRow("转发日志", "查看 / 清空最近记录", icon = Icons.Filled.History, onClick = onOpenLog)

app/src/main/java/com/a2i/forwarder/ui/screens/UpdateDialog.kt

@@ -0,0 +1,121 @@
+package com.a2i.forwarder.ui.screens
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Button
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.LinearProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import com.a2i.forwarder.A2iApp
+import com.a2i.forwarder.core.UpdateInfo
+import kotlinx.coroutines.launch
+import java.io.File
+import java.util.Locale
+
+@Composable
+fun UpdateDialog(info: UpdateInfo, onDismiss: () -> Unit) {
+    val app = A2iApp.instance
+    val downloading by app.updateChecker.downloading.collectAsState()
+    val progress by app.updateChecker.downloadProgress.collectAsState()
+    var downloadedFile by remember { mutableStateOf<File?>(null) }
+
+    AlertDialog(
+        onDismissRequest = { if (!downloading) onDismiss() },
+        title = { Text("发现新版本 v${info.latestVersion}") },
+        text = {
+            Column {
+                Text(
+                    "安装包大小：${formatSize(info.apkSize)}",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+                Spacer(Modifier.size(8.dp))
+                Column(
+                    modifier = Modifier
+                        .heightIn(max = 240.dp)
+                        .verticalScroll(rememberScrollState()),
+                ) {
+                    val notes = info.releaseNotes.ifBlank { "（作者未提供更新说明）" }
+                    Text(notes, style = MaterialTheme.typography.bodyMedium)
+                }
+                if (downloading) {
+                    Spacer(Modifier.size(12.dp))
+                    LinearProgressIndicator(
+                        progress = { progress / 100f },
+                        modifier = Modifier.fillMaxWidth(),
+                    )
+                    Spacer(Modifier.size(4.dp))
+                    Text(
+                        "$progress%",
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+                downloadedFile?.let {
+                    Spacer(Modifier.size(8.dp))
+                    Text(
+                        "下载完成，点击「安装」继续",
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.tertiary,
+                    )
+                }
+            }
+        },
+        confirmButton = {
+            if (downloadedFile == null) {
+                Button(
+                    onClick = {
+                        app.appScope.launch {
+                            val f = app.updateChecker.download(info)
+                            if (f != null) downloadedFile = f
+                        }
+                    },
+                    enabled = !downloading,
+                ) {
+                    if (downloading) {
+                        CircularProgressIndicator(Modifier.size(16.dp), strokeWidth = 2.dp)
+                    } else {
+                        Text("下载并安装")
+                    }
+                }
+            } else {
+                Button(onClick = { app.updateChecker.install(downloadedFile!!) }) { Text("安装") }
+            }
+        },
+        dismissButton = {
+            Row {
+                TextButton(
+                    onClick = { app.updateChecker.ignoreVersion(info.latestVersion); onDismiss() },
+                    enabled = !downloading,
+                ) { Text("忽略此版本") }
+                TextButton(onClick = onDismiss, enabled = !downloading) { Text("稍后") }
+            }
+        },
+    )
+}
+
+fun formatSize(bytes: Long): String {
+    if (bytes <= 0) return "未知"
+    val kb = bytes / 1024.0
+    return if (kb >= 1024) String.format(Locale.US, "%.1f MB", kb / 1024) else String.format(Locale.US, "%.0f KB", kb)
+}

app/src/main/res/xml/file_paths.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths>
+    <external-files-path name="updates" path="." />
+    <cache-path name="cache" path="." />
+</paths>