智能下载与自动安装示例：高效管理APK和图片的完整性验证
智能下载与自动安装示例：高效管理APK和图片的完整性验证// 确保有定义 http 对象
var http = new okHttp();
// 下载文件
http.downloadFile("https://dldir1.qq.com/weixin/android/weixin8053android2740_0x28003533_arm64.apk",
"/sdcard/Pictures/11.apk");
// 定期检查文件是否下载完成
var downloadAppInterval = setInterval(function() {
if (isFileDownloaded("/sdcard/Pictures/11.apk")) {
// 在安装应用前检查是否已经安装
if (!input.isSetup()) {
// 安装应用
if (app.installApp("/sdcard/Pictures/11.apk")) {
console.log("应用安装成功");
} else {
console.log("应用安装失败");
}
} else {
console.log("应用已经安装，无需重新安装");
}
clearInterval(downloadAppInterval); // 停止检查
}
}, 5000); // 每 5 秒检查一次
// 下载图片
http.downloadFile("http://bbs.niubt.cn/123/bd.gif",
"/sdcard/Pictures/image.gif");
// 定期检查图片文件是否下载完成
var downloadImageInterval = setInterval(function() {
if (isFileDownloaded("/sdcard/Pictures/image.gif")) {
// 处理图片下载完成后的逻辑
console.log("图片下载完成");
clearInterval(downloadImageInterval); // 停止检查
}
}, 5000); // 每 5 秒检查一次
// 检查文件是否下载完成
function isFileDownloaded(filePath) {
console.log("正在检查文件是否存在: " + filePath);
// 使用 file.isExists 方法来判断文件是否存在
return file.isExists(filePath); // 确保使用正确的方法
}
<p style="box-sizing: border-box; margin-bottom: 1.5em; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif;">这段代码主要是关于在一个可能的 Android 环境下使用 JavaScript 下载文件和图片，并检查下载状态。下面是代码的逐部分解释：</p><h3 id="h3-1-http-" style="box-sizing: border-box; position: relative; margin-top: 1em; margin-bottom: 1.5em; line-height: 1.75; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif; font-size: 1.25em !important;"><a name="1. 创建 HTTP 对象" class="reference-link" style="color: rgb(65, 131, 196); box-sizing: border-box; background: 0px 0px;"></a>1. 创建 HTTP 对象</h3><pre style="font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 11.9px; line-height: 1.6; font-family: "YaHei Consolas Hybrid", Consolas, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Helvetica, monospace, monospace; box-sizing: border-box; overflow-wrap: normal; margin-bottom: 1.5em; padding: 1em; overflow: auto; background: rgb(56, 69, 72); border-radius: 4px; border: 1px solid rgb(221, 221, 221); position: relative; color: rgb(209, 210, 210);"><code class="hljs csharp" style="box-sizing: border-box; background: 0px 0px transparent; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; border-radius: 3px; border: 0px; word-break: normal; display: block; max-width: none; overflow-x: auto; overflow-y: initial; line-height: inherit; overflow-wrap: normal;"><span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">var</span> http = <span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">new</span> okHttp();
</code></pre><ul style="box-sizing: border-box; padding-left: 2em; margin-bottom: 1.5em; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif;"><li style="box-sizing: border-box;">这里创建了一个 <code style="box-sizing: border-box; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; padding: 3px; background: rgb(249, 249, 249); border-radius: 3px; border: 1px solid rgb(221, 221, 221); color: rgb(64, 158, 255);">okHttp</code> 对象，用于处理后续的文件和图片下载请求。</li></ul><h3 id="h3-2-apk-" style="box-sizing: border-box; position: relative; margin-top: 1em; margin-bottom: 1.5em; line-height: 1.75; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif; font-size: 1.25em !important;"><a name="2. 下载 APK 文件" class="reference-link" style="color: rgb(65, 131, 196); box-sizing: border-box; background: 0px 0px;"></a>2. 下载 APK 文件</h3><pre style="font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 11.9px; line-height: 1.6; font-family: "YaHei Consolas Hybrid", Consolas, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Helvetica, monospace, monospace; box-sizing: border-box; overflow-wrap: normal; margin-bottom: 1.5em; padding: 1em; overflow: auto; background: rgb(56, 69, 72); border-radius: 4px; border: 1px solid rgb(221, 221, 221); position: relative; color: rgb(209, 210, 210);"><code class="hljs less" style="box-sizing: border-box; background: 0px 0px transparent; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; border-radius: 3px; border: 0px; word-break: normal; display: block; max-width: none; overflow-x: auto; overflow-y: initial; line-height: inherit; overflow-wrap: normal;"><span class="hljs-selector-tag" style="box-sizing: border-box; color: rgb(224, 108, 117);">http</span><span class="hljs-selector-class" style="box-sizing: border-box; color: rgb(209, 154, 102);">.downloadFile</span>(<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"https://dldir1.qq.com/weixin/android/weixin8053android2740_0x28003533_arm64.apk"</span>,
<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"/sdcard/Pictures/11.apk"</span>);
</code></pre><ul style="box-sizing: border-box; padding-left: 2em; margin-bottom: 1.5em; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif;"><li style="box-sizing: border-box;">该行代码通过 <code style="box-sizing: border-box; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; padding: 3px; background: rgb(249, 249, 249); border-radius: 3px; border: 1px solid rgb(221, 221, 221); color: rgb(64, 158, 255);">http.downloadFile</code> 方法从指定的网址下载 APK 文件，并将其保存到 <code style="box-sizing: border-box; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; padding: 3px; background: rgb(249, 249, 249); border-radius: 3px; border: 1px solid rgb(221, 221, 221); color: rgb(64, 158, 255);">/sdcard/Pictures/11.apk</code> 路径。</li></ul><h3 id="h3-3-apk-" style="box-sizing: border-box; position: relative; margin-top: 1em; margin-bottom: 1.5em; line-height: 1.75; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif; font-size: 1.25em !important;"><a name="3. 定期检查 APK 文件下载状态" class="reference-link" style="color: rgb(65, 131, 196); box-sizing: border-box; background: 0px 0px;"></a>3. 定期检查 APK 文件下载状态</h3><pre style="font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 11.9px; line-height: 1.6; font-family: "YaHei Consolas Hybrid", Consolas, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Helvetica, monospace, monospace; box-sizing: border-box; overflow-wrap: normal; margin-bottom: 1.5em; padding: 1em; overflow: auto; background: rgb(56, 69, 72); border-radius: 4px; border: 1px solid rgb(221, 221, 221); position: relative; color: rgb(209, 210, 210);"><code class="hljs javascript" style="box-sizing: border-box; background: 0px 0px transparent; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; border-radius: 3px; border: 0px; word-break: normal; display: block; max-width: none; overflow-x: auto; overflow-y: initial; line-height: inherit; overflow-wrap: normal;"><span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">var</span> downloadAppInterval = <span class="hljs-built_in" style="box-sizing: border-box; color: rgb(230, 192, 123);">setInterval</span>(<span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">function</span>(<span class="hljs-params" style="box-sizing: border-box;"></span>) </span>{
<span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">if</span> (isFileDownloaded(<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"/sdcard/Pictures/11.apk"</span>)) {
<span class="hljs-comment" style="box-sizing: border-box; color: rgb(170, 170, 170); font-style: italic;">// 在安装应用前检查是否已经安装</span>
<span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">if</span> (!input.isSetup()) {
<span class="hljs-comment" style="box-sizing: border-box; color: rgb(170, 170, 170); font-style: italic;">// 安装应用</span>
<span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">if</span> (app.installApp(<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"/sdcard/Pictures/11.apk"</span>)) {
<span class="hljs-built_in" style="box-sizing: border-box; color: rgb(230, 192, 123);">console</span>.log(<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"应用安装成功"</span>);
} <span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">else</span> {
<span class="hljs-built_in" style="box-sizing: border-box; color: rgb(230, 192, 123);">console</span>.log(<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"应用安装失败"</span>);
}
} <span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">else</span> {
<span class="hljs-built_in" style="box-sizing: border-box; color: rgb(230, 192, 123);">console</span>.log(<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"应用已经安装，无需重新安装"</span>);
}
<span class="hljs-built_in" style="box-sizing: border-box; color: rgb(230, 192, 123);">clearInterval</span>(downloadAppInterval); <span class="hljs-comment" style="box-sizing: border-box; color: rgb(170, 170, 170); font-style: italic;">// 停止检查</span>
}
}, <span class="hljs-number" style="box-sizing: border-box; color: rgb(209, 154, 102);">5000</span>); <span class="hljs-comment" style="box-sizing: border-box; color: rgb(170, 170, 170); font-style: italic;">// 每 5 秒检查一次</span>
</code></pre><ul style="box-sizing: border-box; padding-left: 2em; margin-bottom: 1.5em; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif;"><li style="box-sizing: border-box;">使用 <code style="box-sizing: border-box; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; padding: 3px; background: rgb(249, 249, 249); border-radius: 3px; border: 1px solid rgb(221, 221, 221); color: rgb(64, 158, 255);">setInterval</code> 方法每 5 秒检查一次 APK 文件是否下载完成。</li><li style="box-sizing: border-box;">如果文件下载完成，则通过 <code style="box-sizing: border-box; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; padding: 3px; background: rgb(249, 249, 249); border-radius: 3px; border: 1px solid rgb(221, 221, 221); color: rgb(64, 158, 255);">isFileDownloaded</code> 函数检查文件是否存在。</li><li style="box-sizing: border-box;">如果 APK 文件存在，进一步检查应用是否已经安装。<ul style="box-sizing: border-box; padding-left: 2em;"><li style="box-sizing: border-box;">如果没有安装，尝试安装应用并打印安装结果。</li><li style="box-sizing: border-box;">如果已经安装，输出不需要重新安装的信息。</li></ul></li><li style="box-sizing: border-box;">下载完成后，使用 <code style="box-sizing: border-box; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; padding: 3px; background: rgb(249, 249, 249); border-radius: 3px; border: 1px solid rgb(221, 221, 221); color: rgb(64, 158, 255);">clearInterval</code> 停止检查。</li></ul><h3 id="h3-4-" style="box-sizing: border-box; position: relative; margin-top: 1em; margin-bottom: 1.5em; line-height: 1.75; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif; font-size: 1.25em !important;"><a name="4. 下载图片" class="reference-link" style="color: rgb(65, 131, 196); box-sizing: border-box; background: 0px 0px;"></a>4. 下载图片</h3><pre style="font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 11.9px; line-height: 1.6; font-family: "YaHei Consolas Hybrid", Consolas, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Helvetica, monospace, monospace; box-sizing: border-box; overflow-wrap: normal; margin-bottom: 1.5em; padding: 1em; overflow: auto; background: rgb(56, 69, 72); border-radius: 4px; border: 1px solid rgb(221, 221, 221); position: relative; color: rgb(209, 210, 210);"><code class="hljs less" style="box-sizing: border-box; background: 0px 0px transparent; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; border-radius: 3px; border: 0px; word-break: normal; display: block; max-width: none; overflow-x: auto; overflow-y: initial; line-height: inherit; overflow-wrap: normal;"><span class="hljs-selector-tag" style="box-sizing: border-box; color: rgb(224, 108, 117);">http</span><span class="hljs-selector-class" style="box-sizing: border-box; color: rgb(209, 154, 102);">.downloadFile</span>(<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"http://bbs.niubt.cn/123/bd.gif"</span>,
<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"/sdcard/Pictures/image.gif"</span>);
</code></pre><ul style="box-sizing: border-box; padding-left: 2em; margin-bottom: 1.5em; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif;"><li style="box-sizing: border-box;">这行代码与之前类似，从指定网址下载一张图片，并保存到 <code style="box-sizing: border-box; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; padding: 3px; background: rgb(249, 249, 249); border-radius: 3px; border: 1px solid rgb(221, 221, 221); color: rgb(64, 158, 255);">/sdcard/Pictures/image.gif</code> 路径。</li></ul><h3 id="h3-5-" style="box-sizing: border-box; position: relative; margin-top: 1em; margin-bottom: 1.5em; line-height: 1.75; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif; font-size: 1.25em !important;"><a name="5. 定期检查图片下载状态" class="reference-link" style="color: rgb(65, 131, 196); box-sizing: border-box; background: 0px 0px;"></a>5. 定期检查图片下载状态</h3><pre style="font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 11.9px; line-height: 1.6; font-family: "YaHei Consolas Hybrid", Consolas, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Helvetica, monospace, monospace; box-sizing: border-box; overflow-wrap: normal; margin-bottom: 1.5em; padding: 1em; overflow: auto; background: rgb(56, 69, 72); border-radius: 4px; border: 1px solid rgb(221, 221, 221); position: relative; color: rgb(209, 210, 210);"><code class="hljs javascript" style="box-sizing: border-box; background: 0px 0px transparent; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; border-radius: 3px; border: 0px; word-break: normal; display: block; max-width: none; overflow-x: auto; overflow-y: initial; line-height: inherit; overflow-wrap: normal;"><span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">var</span> downloadImageInterval = <span class="hljs-built_in" style="box-sizing: border-box; color: rgb(230, 192, 123);">setInterval</span>(<span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">function</span>(<span class="hljs-params" style="box-sizing: border-box;"></span>) </span>{
<span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">if</span> (isFileDownloaded(<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"/sdcard/Pictures/image.gif"</span>)) {
<span class="hljs-comment" style="box-sizing: border-box; color: rgb(170, 170, 170); font-style: italic;">// 处理图片下载完成后的逻辑</span>
<span class="hljs-built_in" style="box-sizing: border-box; color: rgb(230, 192, 123);">console</span>.log(<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"图片下载完成"</span>);
<span class="hljs-built_in" style="box-sizing: border-box; color: rgb(230, 192, 123);">clearInterval</span>(downloadImageInterval); <span class="hljs-comment" style="box-sizing: border-box; color: rgb(170, 170, 170); font-style: italic;">// 停止检查</span>
}
}, <span class="hljs-number" style="box-sizing: border-box; color: rgb(209, 154, 102);">5000</span>); <span class="hljs-comment" style="box-sizing: border-box; color: rgb(170, 170, 170); font-style: italic;">// 每 5 秒检查一次</span>
</code></pre><ul style="box-sizing: border-box; padding-left: 2em; margin-bottom: 1.5em; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif;"><li style="box-sizing: border-box;">同样的逻辑用来检查图片文件是否下载完成。</li><li style="box-sizing: border-box;">如果图片文件存在，输出 “图片下载完成” 的信息，并使用 <code style="box-sizing: border-box; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; padding: 3px; background: rgb(249, 249, 249); border-radius: 3px; border: 1px solid rgb(221, 221, 221); color: rgb(64, 158, 255);">clearInterval</code> 停止检查。</li></ul><h3 id="h3-6-" style="box-sizing: border-box; position: relative; margin-top: 1em; margin-bottom: 1.5em; line-height: 1.75; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif; font-size: 1.25em !important;"><a name="6. 检查文件是否下载完成的函数" class="reference-link" style="color: rgb(65, 131, 196); box-sizing: border-box; background: 0px 0px;"></a>6. 检查文件是否下载完成的函数</h3><pre style="font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 11.9px; line-height: 1.6; font-family: "YaHei Consolas Hybrid", Consolas, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Helvetica, monospace, monospace; box-sizing: border-box; overflow-wrap: normal; margin-bottom: 1.5em; padding: 1em; overflow: auto; background: rgb(56, 69, 72); border-radius: 4px; border: 1px solid rgb(221, 221, 221); position: relative; color: rgb(209, 210, 210);"><code class="hljs javascript" style="box-sizing: border-box; background: 0px 0px transparent; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; border-radius: 3px; border: 0px; word-break: normal; display: block; max-width: none; overflow-x: auto; overflow-y: initial; line-height: inherit; overflow-wrap: normal;"><span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">function</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(97, 174, 238);">isFileDownloaded</span>(<span class="hljs-params" style="box-sizing: border-box;">filePath</span>) </span>{
<span class="hljs-built_in" style="box-sizing: border-box; color: rgb(230, 192, 123);">console</span>.log(<span class="hljs-string" style="box-sizing: border-box; color: rgb(152, 195, 121);">"正在检查文件是否存在: "</span> + filePath);
<span class="hljs-comment" style="box-sizing: border-box; color: rgb(170, 170, 170); font-style: italic;">// 使用 file.isExists 方法来判断文件是否存在</span>
<span class="hljs-keyword" style="box-sizing: border-box; color: rgb(198, 120, 221);">return</span> file.isExists(filePath); <span class="hljs-comment" style="box-sizing: border-box; color: rgb(170, 170, 170); font-style: italic;">// 确保使用正确的方法</span>
}
</code></pre><ul style="box-sizing: border-box; padding-left: 2em; margin-bottom: 1.5em; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif;"><li style="box-sizing: border-box;">该函数根据传入的文件路径检查文件是否存在，并返回布尔值。</li><li style="box-sizing: border-box;">通过 <code style="box-sizing: border-box; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; padding: 3px; background: rgb(249, 249, 249); border-radius: 3px; border: 1px solid rgb(221, 221, 221); color: rgb(64, 158, 255);">file.isExists</code> 方法判断文件是否已经下载到指定路径。</li></ul><p style="box-sizing: border-box; color: rgb(51, 51, 51); font-family: "Microsoft YaHei", Helvetica, "Meiryo UI", "Malgun Gothic", "Segoe UI", "Trebuchet MS", Monaco, monospace, Tahoma, STXihei, 华文细黑, STHeiti, "Helvetica Neue", "Droid Sans", "wenquanyi micro hei", FreeSans, Arimo, Arial, SimSun, 宋体, Heiti, 黑体, sans-serif;">这段代码的核心功能是通过 <code style="box-sizing: border-box; font-family: Consolas, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace; padding: 3px; margin-right: 4px; margin-left: 5px; background: rgb(249, 249, 249); border-radius: 3px; border: 1px solid rgb(221, 221, 221); color: rgb(64, 158, 255);">okHttp</code> 下载文件（APK 和图片），并实施定期检查，以确保下载过程的可靠性。通过简单的逻辑来决定是否需要安装应用，及处理图片下载后的逻辑输出。这种方式适合于需要保持响应和反馈的下载流程。</p><p></p>
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