最近做了一个Android浏览器，当然功能比较简单，主要实现了自己想要的一些功能……现在有好多浏览器为什么还要自己写？当你使用的时候总有那么一些地方不如意，于是就想自己写一个。
开发环境：Xamarin Android(非Forms)+联想机子（5.0）+荣耀机子（8.0）
【开发目标】
1、浏览器的基本功能，关联Http和Https(在另一个APP中打开网页时，可以弹出本应用)
2、创建应用目录，用来存放离线网页文件
3、可以离线保存网页（格式为mht）
4、关联mht和mhtml格式的文件
【涉及到的技术点】
1、重写Activity中的OnBackPressed方法，实现webview回退和再按一次退出程序的功能
2、重写Activity中的OnConfigurationChanged方法，实现横竖屏功能
【webview相关技术点】
1、开启一些常用的设置：JavaScriptEnabled、DomStorageEnabled（如果DomStorageEnabled不启用，网页中的下拉刷新和加载更多将不起作用；例子：百度首页加载新闻）
2、重写WebViewClient中的ShouldOverrideUrlLoading方法，在点击打开网页中的链接时，用自己的webview中打开连接，而不是打开其他的浏览器
3、重写WebChromeClient中的OnReceivedTitle和OnProgressChanged方法，分别获取页面标题（作为离线文件的名称）和加载进度
4、采用事件的方式，通知主Activity关于页面加载开始、加载结束、标题、加载进度等的一些事情，进而更新UI（这里和Java的写法有些不同）
5、页面加载进度条
【悬浮按钮】1、全屏（退出）按钮 2、保存网页 3、扫描二维码（版本兼容问题尚未实现）
【网址输入框】
1、输入正确的网址之后点击输入法中的“前往”调转
2、隐藏输入法
以上列到的功能基本实现，最后在荣耀V10上测试时，其他的功能还好，就是在打开离线文件时也不报错，就是打不开……郁闷啊！最后查了一下也没有找到原因。这里说一下场景，以方便大神发现问题，希望大神不吝赐教。在我的联想手机上测试时发现本地文件路径是这样的：file:///storage/emulated/0/DDZMyBrowser/SavePages/1.mht 此时可以正常浏览，而V10中得到的路径是这样的，内部存储：content://com.huawei.hidisk.fileprovider/root/storage/emulated/0/DDZMyBrowser/SavePages/1.mht SD卡：content://com.huawei.hidisk.fileprovider/root/storage/0ABF-6213/1.mht 这两个都打不开。我查询的结果，这路径应该是利用FileProvider生成的（7.0以上），哎，并非真正的android开发，并不太懂，一脸懵逼，不知道是不是因为这个原因……开始我还寄希望于将content://转为file:///格式的，但是都失败了，最后想想网上说的webview支持content://开头的啊，自己在输入框中手动修改为：file:///storage/emulated/0/DDZMyBrowser/SavePages/1.mht 发现是可以征程浏览的……
上一下截图：
1、应用首页
2、再按一次退出程序
3、横屏
4、竖屏
5、网页中的下拉刷新
6、加载更多
7、用自己的webview中打开连接，而不是打开其他的浏览器；进度条
8、全屏
9、离线保存
10、关联MHT
11、关联HTTP和HTTPS
12、actionGo
13、最后再来一张V10加载异常的图片
去去去，传上去之后发现图片太大了，全是百度的图片……这事儿弄得
最后在贴一下代码，记录一下
CS代码：
using Android.App;
using Android.Widget;
using Android.OS;
using Android.Webkit;
using System;
using Android.Support.Design.Widget;
using Android.Content;
using Android.Views;
using Java.IO;
using Android.Views.InputMethods;
using Android.Content.PM;
using Android.Content.Res;
using Android.Provider;
using Android.Database; namespace DDZ.MyBrowser
{
/// <summary>
/// 获取网页Title
/// </summary>
/// <param name="title"></param>
public delegate void MyWebViewTitleDelegate(string title); /// <summary>
/// 获取网页加载进度
/// </summary>
public delegate void MyWebViewProgressChangedDelegate(int newProgress); /// <summary>
/// 网页加载完成事件
/// </summary>
public delegate void MyWebViewPageFinishedDelegate(); [IntentFilter(
new[] { Intent.ActionView },
Categories = new[] { Intent.CategoryDefault, Intent.CategoryBrowsable },
DataSchemes = new[] { "http", "https" })]
[IntentFilter(
new[] { Intent.ActionView },
Categories = new[] { Intent.CategoryDefault, Intent.CategoryBrowsable },
DataSchemes = new[] { "file", "content" }, DataMimeType = "*/*", DataHost = "*", DataPathPattern = ".*\\\\.mhtml")]
[IntentFilter(
new[] { Intent.ActionView },
Categories = new[] { Intent.CategoryDefault, Intent.CategoryBrowsable },
DataMimeType = "*/*", DataSchemes = new[] { "file", "content" }, DataHost = "*", DataPathPattern = ".*\\\\.mht")]
[Activity(Label = "@string/app_name", Theme = "@style/AppTheme", MainLauncher = true,
ConfigurationChanges = ConfigChanges.Orientation | ConfigChanges.ScreenSize | ConfigChanges.KeyboardHidden)]
public class MainActivity : Activity
{
WebView myBrowser;
EditText edtTxtUrl;
FloatingActionButton fabMain;
FloatingActionButton fabSubQRcodeScan;
FloatingActionButton fabSubToggleFullScreen;
FloatingActionButton fabSubSaveMHT;
ProgressBar myBrowserPBar; private static bool isFabOpen;
private static bool isFullScreen;
private static DateTime lastClickGoBack = DateTime.Now; private static string currentPageTitle;
private readonly string externalStorageDirPath = Android.OS.Environment.ExternalStorageDirectory.AbsolutePath;
private readonly string selfFolderName = "DDZMyBrowser";
private static string selfApplicationDirPath;
protected override void OnCreate(Bundle savedInstanceState)
{
// https://blog.csdn.net/niunan/article/details/71774292
base.OnCreate(savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.activity_main); // 1、浏览器控件相关
myBrowser = FindViewById<WebView>(Resource.Id.myBrowser);
// 要与Javascript交互，则webview必须设置支持Javascript
myBrowser.Settings.JavaScriptEnabled = true;
// 支持通过JS打开新窗口
myBrowser.Settings.JavaScriptCanOpenWindowsAutomatically = true;
myBrowser.Settings.DomStorageEnabled = true;
myBrowser.Settings.AllowFileAccessFromFileURLs = true; var myWebViewClient = new MyWebViewClient();
myWebViewClient.GetWebViewPageFinishedDelegate += MyWebViewClient_GetWebViewPageFinishedDelegate;
myBrowser.SetWebViewClient(myWebViewClient);
var myWebChromeClient = new MyWebChromeClient();
myWebChromeClient.GetWebViewTitleDelegate += MyWebChromeClient_GetWebViewTitleDelegate;
myWebChromeClient.GetWebViewProgressChangedDelegate += MyWebChromeClient_GetWebViewProgressChangedDelegate;
myBrowser.SetWebChromeClient(myWebChromeClient);
edtTxtUrl = FindViewById<EditText>(Resource.Id.edtTxtUrl);
edtTxtUrl.EditorAction += EdtTxtUrl_EditorAction;
myBrowserPBar = FindViewById<ProgressBar>(Resource.Id.myBrowserPBar); // 2、右下方悬浮控件
fabMain = FindViewById<FloatingActionButton>(Resource.Id.fabMain);
fabSubQRcodeScan = FindViewById<FloatingActionButton>(Resource.Id.fabSubQRcodeScan);
fabSubToggleFullScreen = FindViewById<FloatingActionButton>(Resource.Id.fabSubToggleFullScreen);
fabSubSaveMHT = FindViewById<FloatingActionButton>(Resource.Id.fabSubSaveMHT);
fabMain.Click += FabMain_Click;
fabSubQRcodeScan.Click += FabSubQRcodeScan_Click;
fabSubToggleFullScreen.Click += FabSubToggleFullScreen_Click; ;
fabSubSaveMHT.Click += FabSubSaveMHT_Click; // 3、第三方应用使用该应用打开网页时，"this.Intent.DataString" 获取需要打开的网址
// 自己打开时，"this.Intent.DataString" 的值为空
String url = this.Intent.DataString;
if (!String.IsNullOrEmpty(url))
{
if (this.Intent.Data.Scheme == "content")
{
// DocumentsContract.IsDocumentUri(this, this.Intent.Data)：false // this.Intent.Data.Authority：com.huawei.hidisk.fileprovider
// this.Intent.Data.Host：com.huawei.hidisk.fileprovider
// this.Intent.Data.Path：/root/storage/0ABF-6213/xxx.mht
// this.Intent.Data.PathSegments：this.Intent.Data.Path的数组形式 // Android.Support.V4.Content.FileProvider.GetUriForFile()
// this.Intent.SetFlags(ActivityFlags.GrantReadUriPermission).SetFlags(ActivityFlags.GrantWriteUriPermission);
}
}
edtTxtUrl.Text = url;
LoadOnePage(url); // 4、创建应用目录
CreateSelfApplicationFolder();
} private void EdtTxtUrl_EditorAction(object sender, TextView.EditorActionEventArgs e)
{
string inputUrl = edtTxtUrl.Text.Trim();
if (e.ActionId == ImeAction.Go)
{
HideSoftInputFn();
LoadOnePage(inputUrl);
}
} #region 获取WebView加载页面相关信息的一些自定义事件
private void MyWebViewClient_GetWebViewPageFinishedDelegate()
{
Toast.MakeText(this, "加载完成", ToastLength.Long).Show();
} private void MyWebChromeClient_GetWebViewProgressChangedDelegate(int newProgress)
{
myBrowserPBar.Visibility = ViewStates.Visible;
myBrowserPBar.Progress = newProgress;
if (newProgress == )
{
myBrowserPBar.Visibility = ViewStates.Gone;
}
} private void MyWebChromeClient_GetWebViewTitleDelegate(string title)
{
currentPageTitle = title;
}
#endregion #region 悬浮按钮
private void FabMain_Click(object sender, EventArgs e)
{
if (!isFabOpen)
{
HideSoftInputFn();
ShowFabMenu();
}
else
{
CloseFabMenu();
}
SetToggleFullScreenBtnImg();
} private void FabSubQRcodeScan_Click(object sender, EventArgs e)
{
Toast.MakeText(this, "扫描二维码", ToastLength.Long).Show();
} private void FabSubSaveMHT_Click(object sender, EventArgs e)
{
string savePageDirPath = $"{selfApplicationDirPath}{File.Separator}SavePages";
File dir = new File(savePageDirPath);
if (!dir.Exists())
{
bool retBool = dir.Mkdir();
}
myBrowser.SaveWebArchive($"{savePageDirPath}{File.Separator}{currentPageTitle}.mht");
} private void FabSubToggleFullScreen_Click(object sender, EventArgs e)
{
if (isFullScreen)
{ // 目前为全屏状态，修改为非全屏
edtTxtUrl.Visibility = ViewStates.Visible;
this.Window.ClearFlags(WindowManagerFlags.Fullscreen);
}
else
{ // 目前为非全屏状态，修改为全屏
edtTxtUrl.Visibility = ViewStates.Gone;
this.Window.SetFlags(WindowManagerFlags.Fullscreen, WindowManagerFlags.Fullscreen);
}
isFullScreen = !isFullScreen;
SetToggleFullScreenBtnImg();
} private void ShowFabMenu()
{
isFabOpen = true;
fabSubQRcodeScan.Visibility = ViewStates.Visible;
fabSubToggleFullScreen.Visibility = ViewStates.Visible;
fabSubSaveMHT.Visibility = ViewStates.Visible; fabMain.Animate().Rotation(135f);
fabSubQRcodeScan.Animate()
.TranslationY(-600f)
.Rotation(0f);
fabSubToggleFullScreen.Animate()
.TranslationY(-410f)
.Rotation(0f);
fabSubSaveMHT.Animate()
.TranslationY(-220f)
.Rotation(0f);
} private void CloseFabMenu()
{
isFabOpen = false; fabMain.Animate().Rotation(0f);
fabSubQRcodeScan.Animate()
.TranslationY(0f)
.Rotation(90f);
fabSubToggleFullScreen.Animate()
.TranslationY(0f)
.Rotation(90f);
fabSubSaveMHT.Animate()
.TranslationY(0f)
.Rotation(90f); fabSubQRcodeScan.Visibility = ViewStates.Gone;
fabSubToggleFullScreen.Visibility = ViewStates.Gone;
fabSubSaveMHT.Visibility = ViewStates.Gone;
} private void SetToggleFullScreenBtnImg()
{
if (isFullScreen)
{
fabSubToggleFullScreen.SetImageResource(Resource.Drawable.fullscreenExit);
}
else
{
fabSubToggleFullScreen.SetImageResource(Resource.Drawable.fullscreen);
}
}
#endregion #region 重写基类 Activity 方法
public override void OnConfigurationChanged(Configuration newConfig)
{
base.OnConfigurationChanged(newConfig);
if (newConfig.Orientation == Android.Content.Res.Orientation.Portrait)
{
edtTxtUrl.Visibility = ViewStates.Visible;
fabMain.Visibility = ViewStates.Visible;
this.Window.ClearFlags(WindowManagerFlags.Fullscreen);
isFullScreen = false;
Toast.MakeText(Application.Context, "竖屏模式！", ToastLength.Long).Show();
}
else
{
CloseFabMenu();
edtTxtUrl.Visibility = ViewStates.Gone;
fabMain.Visibility = ViewStates.Gone;
this.Window.SetFlags(WindowManagerFlags.Fullscreen, WindowManagerFlags.Fullscreen);
isFullScreen = true;
Toast.MakeText(Application.Context, "横屏模式！", ToastLength.Long).Show();
}
}
public override void OnBackPressed()
{
if (myBrowser.CanGoBack())
{
myBrowser.GoBack();
}
else
{
if ((DateTime.Now - lastClickGoBack).Seconds > )
{
Toast.MakeText(this, $"再按一次退出程序", ToastLength.Long).Show();
lastClickGoBack = DateTime.Now;
}
else
{
this.Finish();
}
}
}
#endregion private void LoadOnePage(String url = "")
{
currentPageTitle = null;
if (String.IsNullOrEmpty(url)) url = "https://www.baidu.com/";
myBrowser.LoadUrl(url);
} private void HideSoftInputFn()
{
// 隐藏键盘
InputMethodManager imm = (InputMethodManager)this.GetSystemService(Context.InputMethodService);
imm.HideSoftInputFromWindow(edtTxtUrl.WindowToken, );
} private void CreateSelfApplicationFolder()
{
selfApplicationDirPath = $"{externalStorageDirPath}{File.Separator}{selfFolderName}";
File dir = new File(selfApplicationDirPath);
if (!dir.Exists())
{
bool retBool = dir.Mkdir();
}
} private String GetRealPathFromURI(Context context, Android.Net.Uri uri)
{
String retPath = null;
if (context == null || uri == null) return retPath;
Boolean isKitKat = Build.VERSION.SdkInt >= BuildVersionCodes.Kitkat;
if (isKitKat && DocumentsContract.IsDocumentUri(context, uri))
{
if (uri.Authority.Equals("com.android.externalstorage.documents", StringComparison.OrdinalIgnoreCase))
{
String docId = DocumentsContract.GetDocumentId(uri);
String[] split = docId.Split(':');
if (split[].Equals("primary", StringComparison.OrdinalIgnoreCase))
{
retPath = Android.OS.Environment.ExternalStorageDirectory + "/" + split[];
}
}
}
return retPath;
} private String GetFilePathFromContentUri(Context context,Android.Net.Uri url)
{
String filePath = null;
String[] filePathColumn = { MediaStore.MediaColumns.Data };
using (ICursor cursor = context.ContentResolver.Query(url, filePathColumn, null, null, null))
{
if (cursor != null && cursor.MoveToFirst())
{
int columnIndex = cursor.GetColumnIndexOrThrow(filePathColumn[]);
if (columnIndex > -)
{
filePath = cursor.GetString(columnIndex);
}
}
}
return filePath;
}
} public class MyWebViewClient : WebViewClient
{
public event MyWebViewPageFinishedDelegate GetWebViewPageFinishedDelegate;
public override bool ShouldOverrideUrlLoading(WebView view, IWebResourceRequest request)
{
view.LoadUrl(request.Url.ToString());
return true;
} public override void OnPageFinished(WebView view, string url)
{
base.OnPageFinished(view, url);
GetWebViewPageFinishedDelegate();
}
} public class MyWebChromeClient : WebChromeClient
{
public event MyWebViewTitleDelegate GetWebViewTitleDelegate;//声明一个事件 public event MyWebViewProgressChangedDelegate GetWebViewProgressChangedDelegate;
public override void OnReceivedTitle(WebView view, string title)
{
base.OnReceivedTitle(view, title);
GetWebViewTitleDelegate(title);
} public override void OnProgressChanged(WebView view, int newProgress)
{
base.OnProgressChanged(view, newProgress);
GetWebViewProgressChangedDelegate(newProgress);
}
}
}
布局代码：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ProgressBar
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="match_parent"
android:layout_height="3dip"
android:max="100"
android:progress="0"
android:visibility="gone"
android:id="@+id/myBrowserPBar" />
<android.webkit.WebView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:id="@+id/myBrowser" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/edtTxtUrl"
android:inputType="text"
android:singleLine="true"
android:imeOptions="actionGo"
android:hint="请输入网址" />
</LinearLayout>
</LinearLayout>
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_margin="18dp"
android:visibility="gone"
android:rotation="90"
android:src="@drawable/qrcodeScan"
app:fabSize="mini"
android:id="@+id/fabSubQRcodeScan" />
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_margin="18dp"
android:visibility="gone"
android:rotation="90"
android:src="@drawable/saveMht"
app:fabSize="mini"
android:id="@+id/fabSubSaveMHT" />
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_margin="18dp"
android:visibility="gone"
android:rotation="90"
app:fabSize="mini"
android:id="@+id/fabSubToggleFullScreen" />
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_margin="10dp"
android:src="@drawable/plus"
app:fabSize="normal"
android:id="@+id/fabMain" />
</RelativeLayout>
用到的一些权限
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
<uses-permission android:name="android.permission.BIND_INPUT_METHOD" />
到此就结束了，webview在8.0下打开content://文件失败的问题，如果有大神看到，希望帮忙解答，十分感谢！以后有机会在慢慢完善他的功能。
【2018-06-26更新】
昨天在小米note3测试本应用，本来是想测试一下看看能不能打开离线文件的问题，但是连关联MHT都不行，打开的时候，应用列表没有该应用……郁闷了，越淌水越深啊！
【2018-11-08更新】
开始因为版本兼容的问题，扫描二维码未处理，一直想着过后看看官方能不能解决，但是今天看看，还是不行……但是VS给出了解决方案：
VS会依次提示单独安装上述的几个包，开始这个项目只安装了一个包，现在的依赖如下：
这次添加的相机权限
<uses-permission android:name="android.permission.CAMERA" />
相机相关代码
1、初始化
protected override void OnCreate(Bundle savedInstanceState)
{
………………
………………
// 5、初始化
MobileBarcodeScanner.Initialize(Application);
}
2、点击扫描二维码执行的代码
private void FabSubQRcodeScan_Click(object sender, EventArgs e)
{
//Toast.MakeText(this, "扫描二维码", ToastLength.Long).Show();
Task.Run(() =>
{
var scanner = new MobileBarcodeScanner();
var result = scanner.Scan();
if (result != null)
{
string scanResult = result.Result.Text;
this.RunOnUiThread(new Java.Lang.Runnable(() =>
{
edtTxtUrl.Text = scanResult;
LoadOnePage(scanResult);
}));
}
});
}
经过这次更新，就可以扫描二维码了……