c# - 如何在 Xamarin.Forms 中为 ToolbarItem 制作自定义渲染器？

问题描述

我正在使用 Xamarin.Forms 应用程序。我正在尝试通过单击工具栏项将 Speech to Text 功能添加到 Xamarin.Forms。当我单击工具上的按钮时，我希望内置电话语音服务打开并将我的语音转换为文本并添加到页面标签。

问题：为了触发特定于 android 的语音服务。我需要工具栏项的自定义渲染器。因此，我可以在该自定义渲染器的 OnClick 方法中将语音代码添加到文本中。但我似乎找不到工具栏项的渲染器类。

这是我当前尝试工具栏项渲染器的代码

VoiceToolbarItemRenderer.cs

[assembly: ExportRenderer(typeof(VoiceToolbarItem), typeof(VoiceToolbarItemRenderer))]

namespace Xamarin_App.Droid
{
    public class VoiceToolbarItemRenderer : PageRenderer, Android.Views.View.IOnClickListene
{

    private bool isRecording;
    private readonly int VOICE = 10;
    private MainActivity activity;

    private VoiceToolbarItem sharedToolbarItem;
    private Toolbar nativeButton;

    private SpeechRecognizer mSpeechRecognizer;
    private Intent mSpeechRecognizerIntent;


    public VoiceToolbarItemRenderer(Context context) : base(context)
    {
        isRecording = false;
    }

    protected override void OnElementChanged(ElementChangedEventArgs<Page> e)
    {
        base.OnElementChanged(e);
        activity = this.Context as MainActivity;
        nativeButton = new global::Android.Widget.Toolbar(Context);

        if (e.OldElement == null)
        {
            // perform initial setup
            //SetNativeControl();
            nativeButton.Clickable = true;
            nativeButton.Focusable = true;

            nativeButton.SetOnClickListener(this);

        }

        if (e.OldElement != null)
        {
            activity.ActivityResult -= HandleActivityResult;
        }

        if (e.NewElement != null)
        {
            activity.ActivityResult += HandleActivityResult;
            sharedToolbarItem = e.NewElement.ToolbarItems as VoiceToolbarItem;
        }
    }

    public void OnClick(Android.Views.View view)
    {

        try
        {
            string rec = Android.Content.PM.PackageManager.FeatureMicrophone;
            if (rec != "android.hardware.microphone")
            {
                // no microphone, no recording. Disable the button and output an alert
                var alert = new AlertDialog.Builder(Context);
                alert.SetTitle("You don't seem to have a microphone to record with");
                alert.SetPositiveButton("OK", (sender, e) => {

                    return;
                });

                alert.Show();
            }
            else
            {

                // create the intent and start the activity

                var voiceIntent = new Intent(RecognizerIntent.ActionRecognizeSpeech);
                voiceIntent.PutExtra(RecognizerIntent.ExtraLanguageModel, RecognizerIntent.LanguageModelFreeForm);


               // if there is more then 1.5s of silence, consider the speech over
                voiceIntent.PutExtra(RecognizerIntent.ExtraSpeechInputCompleteSilenceLengthMillis, 1500);
                voiceIntent.PutExtra(RecognizerIntent.ExtraSpeechInputPossiblyCompleteSilenceLengthMillis, 1500);
                voiceIntent.PutExtra(RecognizerIntent.ExtraSpeechInputMinimumLengthMillis, 15000);
                voiceIntent.PutExtra(RecognizerIntent.ExtraMaxResults, 1);

                // you can specify other languages recognised here, for example
                // voiceIntent.PutExtra(RecognizerIntent.ExtraLanguage, Java.Util.Locale.German);
                // if you wish it to recognise the default Locale language and German
                // if you do use another locale, regional dialects may not be recognised very well

                voiceIntent.PutExtra(RecognizerIntent.ExtraLanguage, Java.Util.Locale.Default);
                activity.StartActivityForResult(voiceIntent, VOICE);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }

    private void HandleActivityResult(object sender, ActivityResultEventArgs e)
    {
        if (e.RequestCode == VOICE)
        {
            if (e.ResultCode == Result.Ok)
            {
                var matches = e.Data.GetStringArrayListExtra(RecognizerIntent.ExtraResults);
                if (matches.Count != 0)
                {
                    string textInput = matches[0];

                    // limit the output to 500 characters
                    if (textInput.Length > 500)
                        textInput = textInput.Substring(0, 500);
                    sharedToolbarItem.OnTextChanged?.Invoke(textInput);
                    //textBox.Text = textInput;
                }
                else
                    sharedToolbarItem.OnTextChanged?.Invoke("No speech was recognised");
            }
        }

    }

}

}

如果有人有制作toolbarItem 的自定义渲染器的想法或任何其他建议，请告诉我。

标签： c#xamarin.formsxamarin.androidspeech-to-text

c# - 如何在 Xamarin.Forms 中为 ToolbarItem 制作自定义渲染器？

问题描述

解决方案

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