Xamarin Android基本功能实现

Xamarin Android基本功能实现
前文已经配置好开发环境，接下来实现简单的扫描，拍照，相册，蓝牙，wifi，网络信息等基本功能。

主要目录
AndroidManifest.xml 应用权限管理
Main_axml 页面按钮等布局
MainActivity.cs 代码编辑页面

AndroidManifest.xml
注：版本号targetSdkVersion我的开始默认较高为27，写法有变动，调低为了21.

<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="CIPHERLABRK25Test1.CIPHERLABRK25Test1" android:installLocation="auto">
  <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="21" />
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
  <uses-permission android:name="android.permission.CAMERA" />
  <uses-permission android:name="android.permission.FLASHLIGHT" />
  <uses-permission android:name="android.permission.INTERNET" />
  <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
  <uses-permission android:name="android.permission.CAPTURE_VIDEO_OUTPUT" />
  <uses-permission android:name="android.permission.CAPTURE_SECURE_VIDEO_OUTPUT" />
  <uses-permission android:name="android.permission.CAPTURE_AUDIO_OUTPUT" />
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
  <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
  <uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL" />
  <uses-permission android:name="android.permission.BLUETOOTH_PRIVILEGED" />
  <uses-permission android:name="android.permission.BLUETOOTH" />
  <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
  <uses-permission android:name="android.permission.ACCESS_WIFI_STATE">uses-permission>
  <uses-permission android:name="android.permission.CHANGE_WIFI_STATE">uses-permission>
  <uses-permission android:name="android.permission.WAKE_LOCK">uses-permission>
  <uses-permission android:name="android.permission.READ_CONTACTS" />
  <uses-permission android:name="android.permission.WRITE_CONTACTS" />
  
  <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true">application>
manifest>

Main_axml

<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:paddingLeft="10dp"
    android:paddingRight="10dp"
    android:rowCount="6"
    android:columnCount="2">
    
	<Button
        android:id="@+id/camera"  
        android:layout_columnSpan="2"
        android:layout_width="fill_parent"
        android:text="打开摄像头" />
    <Button
        android:id="@+id/bluetooth"      
        android:layout_columnSpan="2"
        android:layout_width="match_parent"
        android:text="蓝牙" />
    <Button
        android:id="@+id/btnScanQRCode"
        android:layout_columnSpan="2"
        android:layout_width="match_parent"
        android:text="扫描二维码" />
    <Button
        android:id="@+id/wifi"
        android:layout_columnSpan="2"
        android:layout_width="match_parent"
        android:text="wifi" />
	<Button
        android:id="@+id/net"
        android:layout_columnSpan="2"
        android:layout_width="match_parent"
        android:text="显示网络信息" />
    <Button
        android:id="@+id/photo"
        android:layout_columnSpan="2"
        android:layout_width="match_parent"
        android:text="打开相册" /> 
    <ImageView
        android:src="@android:drawable/ic_menu_gallery"
        android:layout_width="fill_parent"
        android:layout_height="50.0dp"
        android:id="@+id/imageView1"
        android:adjustViewBounds="true" />
	 <TextView
        android:id="@+id/tvMachineCode"
        android:layout_marginRight="5dp"
        android:textSize="20sp"       
        android:text="" />
    <EditText
        android:id="@+id/txtMachineCode"
        android:textSize="20sp"
        android:maxLength="50"      
        android:layout_width="fill_parent" />
GridLayout>

MainActivity.cs主要代码如下

using System;
using Android.App;
using Android.Bluetooth;
using Android.Content;
using Android.Net.Wifi;
using Android.OS;
using Android.Provider;
using Android.Views;
using Android.Widget;
using Java.IO;
using ZXing.Mobile;

using Environment = Android.OS.Environment;
using Uri = Android.Net.Uri;
using Android.Support.V4.Content;

using Context = Android.Content.Context;
using Android.Runtime;
using Android.Database;
using Java.Util.Jar;
using Plugin.Media;
using Java.Lang;
using String = System.String;
using Android.Graphics;
using System.Collections.Generic;
using Android.Content.PM;
using Android.Net;

/*
 * FastAndroidCamera  2.0.0
 * xamarin.android.support.v4  23.3.0
 * Zxing.net 0.15
 * zxing.net.mobile 2.2.9
 * */

namespace CIPHERLABRK25Test1
{
			public static class App
		{
		    public static File _file;
		    public static File _dir;
		    public static Bitmap bitmap;
		}
		
    [Activity(Label = "ZXing1", MainLauncher = true)]
    public class MainActivity : Activity
    {
        private EditText txtMachineCode;
        private Button Btnscanqrcode;
        private Button TvActiviationCode;
        private Button bluetooth;
        private Button wifi;
        private Button camera;
        private Button net;
        private Button photo;

        //   private ImageView _imageView;
        private ImageView iv;

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);
            MobileBarcodeScanner.Initialize(Application);
            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);

            txtMachineCode = FindViewById<EditText>(Resource.Id.txtMachineCode);
            Btnscanqrcode = FindViewById<Button>(Resource.Id.btnScanQRCode);
            bluetooth = FindViewById<Button>(Resource.Id.bluetooth);
            wifi = FindViewById<Button>(Resource.Id.wifi);
            camera = FindViewById<Button>(Resource.Id.camera);
            photo = FindViewById<Button>(Resource.Id.photo);
            iv = FindViewById<ImageView>(Resource.Id.imageView1);
            net = FindViewById<Button>(Resource.Id.net);

            Btnscanqrcode.Click += Btnscanqrcode_Click;
            bluetooth.Click += bluetooth_Click;
            wifi.Click += wifi_Click;
            net.Click += net_Click;
            photo.Click += photo_Click;

            if (IsThereAnAppToTakePictures())
            {
                CreateDirectoryForPictures();
                camera.Click += TakeAPicture; camera.Click += TakeAPicture;
            }
        }

        private void net_Click(object sender, EventArgs e)
        {
            getCurrentNetType();
        }

        private void getCurrentNetType()
        {
            ConnectivityManager cm = (ConnectivityManager)GetSystemService(ConnectivityService);
            if (cm.ActiveNetworkInfo == null || cm.ActiveNetworkInfo.Equals(""))
            {
                txtMachineCode.Text = "xxxx";
            }
            else
            {
                txtMachineCode.Text = cm.ActiveNetworkInfo.TypeName;
            }
        }

        //获取图册
        private void photo_Click(object sender, EventArgs e)
        {
            File originalFile = new Java.IO.File(Android.OS.Environment.GetExternalStoragePublicDirectory(
                Android.OS.Environment.DirectoryPictures
                ), "zcb_pic_" + SystemClock.CurrentThreadTimeMillis() + ".png");

            Intent _intentCut = new Intent(Intent.ActionGetContent, null);
            _intentCut.SetType("image/*");// 设置文件类型
            _intentCut.PutExtra(MediaStore.ExtraOutput, Android.Net.Uri.FromFile(originalFile));
            _intentCut.PutExtra(MediaStore.ExtraVideoQuality, 1);

            StartActivityForResult(_intentCut, 0);
        }

        //拍照
        private void TakeAPicture(object sender, EventArgs e)
        {
            Intent intent = new Intent(MediaStore.ActionImageCapture);

            App._file = new File(App._dir, String.Format("myPhoto_{0}.jpg", Guid.NewGuid()));       //保存路径

            intent.PutExtra(MediaStore.ExtraOutput, Uri.FromFile(App._file));

            //   StartActivityForResult(intent, 0);
            StartActivity(intent);
        }

        private void CreateDirectoryForPictures()
        {
            App._dir = new File(
                Environment.GetExternalStoragePublicDirectory(
                Environment.DirectoryPictures), "CIPHERLABRK25Test1");
            if (!App._dir.Exists())
            {
                App._dir.Mkdirs();
            }
        }

        private bool IsThereAnAppToTakePictures()
        {
            Intent intent = new Intent(MediaStore.ActionImageCapture);
            IList<ResolveInfo> availableActivities = PackageManager.QueryIntentActivities(intent, PackageInfoFlags.MatchDefaultOnly);
            return availableActivities != null && availableActivities.Count > 0;
        }

        //wifi
        private void wifi_Click(object sender, EventArgs e)
        {
            WifiManager wifi = (WifiManager)GetSystemService(Context.WifiService);

            WifiInfo w = wifi.ConnectionInfo;
            //wifi信息
            txtMachineCode.Text = w.MacAddress + "**" + w.IpAddress;

            if (wifi.IsWifiEnabled)
            {
                wifi.SetWifiEnabled(false);
            }
            else
            {
                wifi.SetWifiEnabled(true);
            }
        }

        //蓝牙
        private void bluetooth_Click(object sender, System.EventArgs e)
        {
            BluetoothAdapter localAdapter = BluetoothAdapter.DefaultAdapter;
            if (!localAdapter.IsEnabled)
            {
                localAdapter.Enable();
            }
            else
            {
                localAdapter.Disable();
            }
        }

        //扫描二维码
        private ZXingScannerFragment scanFragment;

        private View zxingOverlay;

        //public override View OnCreateView(LayoutInflater inflater, ViewGroup p1, Bundle p2)
        //{
        //    return inflater.Inflate(Resource.Layout.Scanner, null);
        //}

        private async void Btnscanqrcode_Click(object sender, System.EventArgs e)
        {
            var scanner = new ZXing.Mobile.MobileBarcodeScanner();
            var result = await scanner.Scan();
            if (result == null)
            {
                return;
            }

            txtMachineCode.Text = result.Text.Trim();
        }

        //图片显示

        protected override void OnActivityResult(int requestCode, [GeneratedEnum] Result ResultStatus, Intent data)
        {
            if (ResultStatus == Result.Ok)
            {
                /*
                * 若系统版本低于4.4，返回原uri
                * 若高于4.4，解析uri后返回
                * */
                if (Android.OS.Build.VERSION.SdkInt >= BuildVersionCodes.Kitkat)
                {
                    var url = Android.Net.Uri.Parse("file://" + GetPath(BaseContext, data.Data));
                    data.SetData(url);

                    //将本地相册照片显示在控件上
                    iv.SetImageURI(Android.Net.Uri.FromFile(new File(GetPath(BaseContext, data.Data))));
                }
            }
        }

        #region 高于 v4.4 版本 解析真实路径

        public static String GetPath(Context context, Android.Net.Uri uri)
        {
            bool isKitKat = Build.VERSION.SdkInt >= BuildVersionCodes.Kitkat;

            // DocumentProvider
            if (isKitKat && DocumentsContract.IsDocumentUri(context, uri))
            {
                // ExternalStorageProvider
                if (isExternalStorageDocument(uri))
                {
                    String docId = DocumentsContract.GetDocumentId(uri);
                    String[] split = docId.Split(':');
                    String type = split[0];

                    if ("primary".Equals(type.ToLower()))
                    {
                        return Android.OS.Environment.ExternalStorageDirectory + "/" + split[1];
                    }

                    // TODO handle non-primary volumes
                }
                // DownloadsProvider
                else if (isDownloadsDocument(uri))
                {
                    String id = DocumentsContract.GetDocumentId(uri);
                    Android.Net.Uri contentUri = ContentUris.WithAppendedId(
                            Android.Net.Uri.Parse("content://downloads/public_downloads"), long.Parse(id));

                    return getDataColumn(context, contentUri, null, null);
                }
                // MediaProvider
                else if (isMediaDocument(uri))
                {
                    String docId = DocumentsContract.GetDocumentId(uri);
                    String[] split = docId.Split(':');
                    String type = split[0];

                    Android.Net.Uri contentUri = null;
                    if ("image".Equals(type))
                    {
                        contentUri = MediaStore.Images.Media.ExternalContentUri;
                    }
                    else if ("video".Equals(type))
                    {
                        contentUri = MediaStore.Video.Media.ExternalContentUri;
                    }
                    else if ("audio".Equals(type))
                    {
                        contentUri = MediaStore.Audio.Media.ExternalContentUri;
                    }

                    String selection = "_id=?";
                    String[] selectionArgs = new String[] {
                    split[1]
            };

                    return getDataColumn(context, contentUri, selection, selectionArgs);
                }
            }
            // MediaStore (and general)
            else
            if ("content".Equals(uri.Scheme.ToLower()))
            {
                // Return the remote address
                if (isGooglePhotosUri(uri))
                    return uri.LastPathSegment;

                return getDataColumn(context, uri, null, null);
            }
            // File
            else if ("file".Equals(uri.Scheme.ToLower()))
            {
                return uri.Path;
            }

            return null;
        }

        public static String getDataColumn(Context context, Android.Net.Uri uri, String selection,
                String[] selectionArgs)
        {
            ICursor cursor = null;
            String column = "_data";
            String[] projection = {
                column
            };

            try
            {
                cursor = context.ContentResolver.Query(uri, projection, selection, selectionArgs,
                        null);
                if (cursor != null && cursor.MoveToFirst())
                {
                    int index = cursor.GetColumnIndexOrThrow(column);
                    return cursor.GetString(index);
                }
            }
            finally
            {
                if (cursor != null)
                    cursor.Close();
            }
            return null;
        }

        /**
         * @param uri The Uri to check.
         * @return Whether the Uri authority is ExternalStorageProvider.
         */

        public static bool isExternalStorageDocument(Android.Net.Uri uri)
        {
            return "com.android.externalstorage.documents".Equals(uri.Authority);
        }

        /**
         * @param uri The Uri to check.
         * @return Whether the Uri authority is DownloadsProvider.
         */

        public static bool isDownloadsDocument(Android.Net.Uri uri)
        {
            return "com.android.providers.downloads.documents".Equals(uri.Authority);
        }

        /**
         * @param uri The Uri to check.
         * @return Whether the Uri authority is MediaProvider.
         */

        public static bool isMediaDocument(Android.Net.Uri uri)
        {
            return "com.android.providers.media.documents".Equals(uri.Authority);
        }

        /**
         * @param uri The Uri to check.
         * @return Whether the Uri authority is Google Photos.
         */

        public static bool isGooglePhotosUri(Android.Net.Uri uri)
        {
            return "com.google.android.apps.photos.content".Equals(uri.Authority);
        }

        #endregion 高于 v4.4 版本 解析真实路径
    }
}