Android : WebView无网络时的图片显示解决方案

解决方案"/>

Android : WebView无网络时的图片显示解决方案

需求场景：必须在已经构建缓存的基础之上，否则数据都无法正常显示，何谈图片呢？

接下来直接上代码喽，小伙伴们如果有更好的解决方式可以随时联系我哦！

            <WebViewandroid:id="@+id/content"android:layout_width="@dimen/dp_328"android:layout_height="wrap_content"android:layout_below="@id/instruction"android:layout_centerHorizontal="true"android:layout_marginTop="@dimen/dp_30"></WebView>

对webView进行配置：

private fun webSetting() {var ws = content.settingsws.javaScriptEnabled = true //与Javascript交互//Todows.setAppCacheEnabled(true)ws.databaseEnabled = truews.domStorageEnabled = true//Todows.setRenderPriority(WebSettings.RenderPriority.HIGH)////设置渲染的优先级ws.defaultFontSize = 17 //设置默认字体大小，默认16，可取值1到72ws.defaultTextEncodingName = "UTF-8"content.isVerticalScrollBarEnabled = falsews.cacheMode = WebSettings.LOAD_NO_CACHE//设置缓存模式</span>

在无网络的情况下：

if (!NetworkUtils.isConnected) {aboutImageSetting()//断网操作
}
content.loadDataWithBaseURL(null, HtmlFormat.getNewContent(t?.content!!), "text/html", "utf-8", null)//加载详情

private fun aboutImageSetting() {content.webViewClient = object : WebViewClient() {// API 21 以上用shouldInterceptRequest(WebView view, WebResourceRequest request)@TargetApi(Build.VERSION_CODES.LOLLIPOP)override fun shouldInterceptRequest(view: WebView?, request: WebResourceRequest?): WebResourceResponse {val toString = request?.url.toString()// 步骤1:判断拦截资源的条件，即判断url里的图片资源if (toString.contains(".jpg")) {// 步骤2:创建一个输入流var stream: InputStream? = nulltry {stream = assets.open("none_picture.png")// 步骤3:获得需要替换的资源(存放在assets文件夹里)} catch (e: IOException) {e.printStackTrace()}// 步骤4:替换资源var res = WebResourceResponse("image/jpeg","utf-8", stream)// 参数1：http请求里该图片的Content-Type// 参数2：编码类型// 参数3：存放着替换资源的输入流（上面创建的那个）return res}return super.shouldInterceptRequest(view, request)}//API21以下用shouldInterceptRequest(WebView view, String url)override fun shouldInterceptRequest(view: WebView?, url: String?): WebResourceResponse {if (url?.contains(".jpg")!!) {var input: InputStream? = nulltry {input = applicationContext.assets.open("none_picture.png")} catch (e: IOException) {e.printStackTrace()}var res = WebResourceResponse("image/jpeg","utf-8", input)return res}return super.shouldInterceptRequest(view, url)}}

最后千万不要忘记添加权限：

<uses-permission android:name="android.permission.INTERNET"/>

上述代码是用Kotlin写的，后续会推出Kotlin的相关笔记，希望大家多多支持！