Files
DotNetSolutionTools/SolutionParityChecker.App/ViewModels/MainWindowViewModel.cs
Matthew Parker aefb12e688 file dialog
2023-08-30 00:07:55 +10:00

122 lines
3.9 KiB
C#

using System;
using System.IO;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Avalonia;
using Avalonia.Controls.ApplicationLifetimes;
using Avalonia.Platform.Storage;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
namespace SolutionParityChecker.App.ViewModels;
public partial class MainWindowViewModel : ViewModelBase
{
public string SolutionFolderPath { get; set; } = string.Empty;
public string SolutionFilePath { get; set; } = string.Empty;
[ObservableProperty]
private string? _fileText;
[RelayCommand]
private async Task OpenFile(CancellationToken token)
{
ErrorMessages?.Clear();
try
{
var file = await DoOpenFilePickerAsync();
if (file is null)
return;
// Limit the text file to 1MB so that the demo won't lag.
if ((await file.GetBasicPropertiesAsync()).Size <= 1024 * 1024 * 1)
{
await using var readStream = await file.OpenReadAsync();
using var reader = new StreamReader(readStream);
FileText = await reader.ReadToEndAsync(token);
}
else
{
throw new Exception("File exceeded 1MB limit.");
}
}
catch (Exception e)
{
ErrorMessages?.Add(e.Message);
}
}
[RelayCommand]
private async Task SaveFile()
{
ErrorMessages?.Clear();
try
{
var file = await DoSaveFilePickerAsync();
if (file is null)
return;
// Limit the text file to 1MB so that the demo won't lag.
if (FileText?.Length <= 1024 * 1024 * 1)
{
var stream = new MemoryStream(Encoding.Default.GetBytes((string)FileText));
await using var writeStream = await file.OpenWriteAsync();
await stream.CopyToAsync(writeStream);
}
else
{
throw new Exception("File exceeded 1MB limit.");
}
}
catch (Exception e)
{
ErrorMessages?.Add(e.Message);
}
}
private async Task<IStorageFile?> DoOpenFilePickerAsync()
{
// For learning purposes, we opted to directly get the reference
// for StorageProvider APIs here inside the ViewModel.
// For your real-world apps, you should follow the MVVM principles
// by making service classes and locating them with DI/IoC.
// See IoCFileOps project for an example of how to accomplish this.
if (
Application.Current?.ApplicationLifetime
is not IClassicDesktopStyleApplicationLifetime desktop
|| desktop.MainWindow?.StorageProvider is not { } provider
)
throw new NullReferenceException("Missing StorageProvider instance.");
var files = await provider.OpenFilePickerAsync(
new FilePickerOpenOptions() { Title = "Open Text File", AllowMultiple = false }
);
return files?.Count >= 1 ? files[0] : null;
}
private async Task<IStorageFile?> DoSaveFilePickerAsync()
{
// For learning purposes, we opted to directly get the reference
// for StorageProvider APIs here inside the ViewModel.
// For your real-world apps, you should follow the MVVM principles
// by making service classes and locating them with DI/IoC.
// See DepInject project for a sample of how to accomplish this.
if (
Application.Current?.ApplicationLifetime
is not IClassicDesktopStyleApplicationLifetime desktop
|| desktop.MainWindow?.StorageProvider is not { } provider
)
throw new NullReferenceException("Missing StorageProvider instance.");
return await provider.SaveFilePickerAsync(
new FilePickerSaveOptions() { Title = "Save Text File" }
);
}
}