xamarin - 如何在 Xamarin Forms 上创建图像选择器？

问题描述

有谁知道是否可以制作这样的图像选择器：

我试过以下插件：

https://github.com/jamesmontemagno/MediaPlugin

https://github.com/matheusneder/Xamarin.Forms.ImagePicker

我不想创建能够执行每个操作的按钮，我想要的是用一个按钮来建议使用哪个应用程序。这个有可能？

谢谢。

标签： xamarinxamarin.formspluginscameragallery

如果要从手机的图片库中挑选一张照片，由于 Xamarin.Forms 不包含此功能，需要使用DependencyService各个平台的原生 API 来访问。

创建接口： IPhotoPickerService.cs

public interface IPhotoPickerService
{
    Task<Stream> GetImageStreamAsync();
}

安卓实现：

MainActivity.cs

public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
    internal static MainActivity Instance { get; private set; }

      ... ...

    // Field, property, and method for Picture Picker
    public static readonly int PickImageId = 1000;

    public TaskCompletionSource<Stream> PickImageTaskCompletionSource { set; get; }

    protected override void OnActivityResult(int requestCode, Result resultCode, Intent intent)
    {
        base.OnActivityResult(requestCode, resultCode, intent);

        if (requestCode == PickImageId)
        {
            if ((resultCode == Result.Ok) && (intent != null))
            {
                Android.Net.Uri uri = intent.Data;
                Stream stream = ContentResolver.OpenInputStream(uri);

                // Set the Stream as the completion of the Task
                PickImageTaskCompletionSource.SetResult(stream);
            }
            else
            {
                PickImageTaskCompletionSource.SetResult(null);
            }
        }
    }
}

PhotoPickerService.cs

public class PhotoPickerService : IPhotoPickerService
{
    public Task<Stream> GetImageStreamAsync()
    {
        // Define the Intent for getting images
        Intent intent = new Intent();
        intent.SetType("image/*");
        intent.SetAction(Intent.ActionGetContent);

        // Start the picture-picker activity (resumes in MainActivity.cs)
        MainActivity.Instance.StartActivityForResult(
            Intent.CreateChooser(intent, "Select Photo"),
            MainActivity.PickImageId);

        // Save the TaskCompletionSource object as a MainActivity property
        MainActivity.Instance.PickImageTaskCompletionSource = new TaskCompletionSource<Stream>();

        // Return Task object
        return MainActivity.Instance.PickImageTaskCompletionSource.Task;
    }
}

有关 IOS、UWP 实现照片选择器的更多信息，您可以查看 MS 文章。https://docs.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/dependency-service/photo-picker

并从链接下载源文件。https://docs.microsoft.com/zh-cn/samples/xamarin/xamarin-forms-samples/dependencyservice/

xamarin - 如何在 Xamarin Forms 上创建图像选择器？

问题描述

解决方案

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