问题描述
我有一个带有简单拨动开关的应用程序，可以打开和关闭手电筒，我需要可以用来检查手电筒是否已打开然后使用它来更改开关的拨动状态的代码。 如果服务报告手电筒打开，我将发送广播意图将其关闭，反之亦然...我的应用程序逻辑在这里
class SecondActivity : AppCompatActivity{
protected override void OnCreate(Bundle onSavedInstanceState){
//Switch deFinition
Switch switch1 = this.FindViewById<Switch>(Resource.Id.switch2);
//Setting the intial status of the switch to be unchecked by default
switch1.Checked=false;
//Adding delegate method to handle switch checked event
switch1.CheckedChange += delegate (object sender,CompoundButton.CheckedChangeEventArgs e)
{
if (e.IsChecked==true)
{
//Switch is on so turn on Flahlight
Flashlight.TurnOnAsync();
Toast.MakeText(Application.Context,"Switch is ON",ToastLength.Long).Show();
}
else
{
//Switch is unchecked so turn off flashlight
Flashlight.TurnOffAsync();
Toast.MakeText(Application.Context,"Switch is OFF",ToastLength.Long).Show();
}
};
//Code to check if flashlight was turned on by an extra app activity
}
}
用户可以在应用程序外部打开手电筒，所以我只需要该代码来检查手电筒是否已打开，然后我将实现广播意图以对开关进行适当的更改，谢谢您的时间和贡献
解决方法
用户可以在应用程序外部打开手电筒，因此我只需要该代码来检查手电筒是否已打开，然后我将实现广播意图，以适当地更改我的开关，
是否要获得以下gif效果？
我要完成两个申请：
-
MyForegroundServiceDemo：使用广播来广播
flashlight（如果启用或未启用），以使broadcastReceiver始终在后台或前台运行，我使用了地面服务来实现它。然后在前台服务器中注册broadcastRecevier。 -
XAndroidBroadcastRece：只需打开/关闭手电筒即可。
这是我的MyForegroundServiceDemo代码。
首先，您需要在AndroidManifest.xml中添加和添加Camera＆Flashlight权限。
然后，这是我的layout.xml
<LinearLayout 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:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="20dp"
android:text="Please see following switch"/>
<Switch
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/switch1"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/button1"
android:text="start"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/button2"
android:text="Stop"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="123@456"/>
</LinearLayout>
这是我的MainActivity.cs。我使用Button1启用了前台服务。并公开Switch，以便我们可以在broadcastReceiver中对其进行控制。
[Activity(Label = "@string/app_name",Theme = "@style/AppTheme",MainLauncher = true)]
public class MainActivity : AppCompatActivity
{
public static MainActivity Instance;
public static Switch switch1;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
Xamarin.Essentials.Platform.Init(this,savedInstanceState);
Instance = this;
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.activity_main);
Button button1 = FindViewById<Button>(Resource.Id.button1);
Button button2 = FindViewById<Button>(Resource.Id.button2);
switch1 = FindViewById<Switch>(Resource.Id.switch1);
button2.Click += Button2_Click;
button1.Click += Button1_Click;
}
Intent intent;
private void Button2_Click(object sender,System.EventArgs e)
{
// throw new System.NotImplementedException();
Android.App.Application.Context.StopService(intent);
}
private void Button1_Click(object sender,System.EventArgs e)
{
intent = new Intent(Android.App.Application.Context,typeof(MyForegroundService));
if (Android.OS.Build.VERSION.SdkInt >= Android.OS.BuildVersionCodes.O)
{
StartForegroundService(intent);
// Android.App.Application.Context.StartForegroundService(intent);
}
}
public override void OnRequestPermissionsResult(int requestCode,string[] permissions,[GeneratedEnum] Android.Content.PM.Permission[] grantResults)
{
Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode,permissions,grantResults);
base.OnRequestPermissionsResult(requestCode,grantResults);
}
}
}
这里是关于MyForegroundService.cs的代码。当我们收到MyReceiver(BroadcastReceiver)中的广播时，我们用MyTorchRegister来标记手电筒的状态
using Android.Hardware.Camera2;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Xamarin.Essentials;
namespace ForegroundServiceDemo
{
[Service]
class MyForegroundService : Service
{
public const int SERVICE_RUNNING_NOTIFICATION_ID = 10000;
[return: GeneratedEnum]
public override StartCommandResult OnStartCommand(Intent intent,[GeneratedEnum] StartCommandFlags flags,int startId)
{
CreateNotificationChannel();
string messageBody = "service starting";
Clipboard.ClipboardContentChanged += Clipboard_ClipboardContentChanged;
// / Create an Intent for the activity you want to start
Intent resultIntent = new Intent(this,typeof(Activity1));
// Create the TaskStackBuilder and add the intent,which inflates the back stack
TaskStackBuilder stackBuilder = TaskStackBuilder.Create(this);
stackBuilder.AddNextIntentWithParentStack(resultIntent);
// Get the PendingIntent containing the entire back stack
PendingIntent resultPendingIntent = stackBuilder.GetPendingIntent(0,PendingIntentFlags.UpdateCurrent);
var notification = new Notification.Builder(this,"10111")
.SetContentIntent(resultPendingIntent)
.SetContentTitle("Foreground")
.SetContentText(messageBody)
.SetSmallIcon(Resource.Drawable.main)
.SetOngoing(true)
.Build();
StartForeground(SERVICE_RUNNING_NOTIFICATION_ID,notification);
MyReceiver receiver = new MyReceiver();
RegisterReceiver(receiver,new IntentFilter("com.Java_Tutorial.CUSTOM_INTENT"));
return StartCommandResult.Sticky;
}
private async void Clipboard_ClipboardContentChanged(object sender,EventArgs e)
{
//throw new NotImplementedException();
var text = await Clipboard.GetTextAsync();
Toast.MakeText(this,text,ToastLength.Long).Show();
if (text.Contains("@"))
{
await Clipboard.SetTextAsync(text.Replace("@",""));
}
}
public override void OnDestroy()
{
base.OnDestroy();
Clipboard.ClipboardContentChanged -= Clipboard_ClipboardContentChanged;
StopForeground(true);
}
public override IBinder OnBind(Intent intent)
{
return null;
}
void CreateNotificationChannel()
{
if (Build.VERSION.SdkInt < BuildVersionCodes.O)
{
return;
}
var channelName = Resources.GetString(Resource.String.channel_name);
var channelDescription = GetString(Resource.String.channel_description);
var channel = new NotificationChannel("10111",channelName,NotificationImportance.Default)
{
Description = channelDescription
};
var notificationManager = (NotificationManager)GetSystemService(NotificationService);
notificationManager.CreateNotificationChannel(channel);
}
}
//do you work
[BroadcastReceiver(Enabled = true,Exported = true)]
public class MyReceiver : BroadcastReceiver
{
public override void OnReceive(Context context,Intent intent)
{
CameraManager cameraManager = (CameraManager)context.GetSystemService(Context.CameraService);
var flashAvailable = cameraManager.GetCameraCharacteristics("0").Get(CameraCharacteristics.FlashInfoAvailable);
cameraManager.RegisterTorchCallback(new MyTorchRegister(),null);
if (MyTorchRegister.isFlashlightOn) {
MainActivity.switch1.Checked = false;
// Toast.MakeText(context,"FlashLight is disabled",ToastLength.Long).Show();
}
else
{
MainActivity.switch1.Checked = true;
// Toast.MakeText(context,"FlashLight is Opened",ToastLength.Long).Show();
}
}
internal class MyTorchRegister : CameraManager.TorchCallback
{
public static bool isFlashlightOn = false;
public override void OnTorchModeChanged(string cameraId,bool enabled)
{
base.OnTorchModeChanged(cameraId,enabled);
isFlashlightOn = enabled;
}
}
}
}
这是XAndroidBroadcastRece演示代码
Switch switch1 = this.FindViewById<Switch>(Resource.Id.switch1);
//Setting the intial status of the switch to be unchecked by default
switch1.Checked = false;
//Adding delegate method to handle switch checked event
switch1.CheckedChange += delegate (object sender,CompoundButton.CheckedChangeEventArgs e)
{
if (e.IsChecked == true)
{
//Switch is on so turn on Flahlight
Flashlight.TurnOnAsync();
Intent intent = new Intent();
intent.SetAction("com.Java_Tutorial.CUSTOM_INTENT");
SendBroadcast(intent);
Toast.MakeText(Application.Context,"Switch is ON",ToastLength.Long).Show();
}
else
{
//Switch is unchecked so turn off flashlight
Flashlight.TurnOffAsync();
Intent intent = new Intent();
intent.SetAction("com.Java_Tutorial.CUSTOM_INTENT");
SendBroadcast(intent);
Toast.MakeText(Application.Context,"Switch is OFF",ToastLength.Long).Show();
}
};