如何在 Android 上使用 .NET MAUI 读取和写入条形码

从上面的MainPage.xaml代码中，我们可以看到复选框决定生成的条形码和二维码是否应该是PDF格式。 接下来，我们设置许可证密钥。 请使用试用或付费许可证密钥进行此步骤。

代码检查并检索barcodeInput变量中的值，然后使用CreateBarcode方法生成条形码。 最后，调用SaveToDownloadsAsync方法，该方法在Android和iOS上都适当地保存文件。

在iOS上，需要自定义文件路径才能将文档导出到Files应用程序。

using IronBarCode;
using System;
using System.IO;
using System.Threading.Tasks;
using Xamarin.Essentials;

namespace IronBarcodeMauiAndroid
{
    public partial class MainPage : ContentPage
    {
        public bool IsGeneratePdfChecked
        {
            get => generatePdfCheckBox.IsChecked;
            set
            {
                generatePdfCheckBox.IsChecked = value;
            }
        }

        public MainPage()
        {
            InitializeComponent();
            // Set the license key for IronBarcode, replace with your actual license key.
            License.LicenseKey = "IRONBARCODE-MYLICENSE-KEY-1EF01";
        }

        private async void WriteBarcode(object sender, EventArgs e)
        {
            try
            {
                if (!string.IsNullOrEmpty(barcodeInput.Text))
                {
                    // Create a barcode from the text input with the EAN13 encoding.
                    var barcode = BarcodeWriter.CreateBarcode(barcodeInput.Text, BarcodeEncoding.EAN13);

                    // Determine the file extension and data format based on the checkbox state.
                    string fileExtension = IsGeneratePdfChecked ? "pdf" : "png";
                    string fileName = $"Barcode_{DateTime.Now:yyyyMMddHHmmss}.{fileExtension}";
                    byte[] fileData = IsGeneratePdfChecked ? barcode.ToPdfBinaryData() : barcode.ToPngBinaryData();

                    // Save the generated barcode to the Downloads folder.
                    await SaveToDownloadsAsync(fileData, fileName);

                    await Application.Current.MainPage.DisplayAlert("Saved", "File saved to Downloads folder", "OK");
                }
            }
            catch (Exception ex)
            {
                // Handle exceptions and log the error.
                System.Diagnostics.Debug.WriteLine(ex);
            }
        }

        private async void WriteQRcode(object sender, EventArgs e)
        {
            try
            {
                if (!string.IsNullOrEmpty(qrInput.Text))
                {
                    // Create a QR code from the text input.
                    var barcode = QRCodeWriter.CreateQrCode(qrInput.Text);

                    // Determine the file extension and data format based on the checkbox state.
                    string fileExtension = IsGeneratePdfChecked ? "pdf" : "png";
                    string fileName = $"QRcode_{DateTime.Now:yyyyMMddHHmmss}.{fileExtension}";
                    byte[] fileData = IsGeneratePdfChecked ? barcode.ToPdfBinaryData() : barcode.ToPngBinaryData();

                    // Save the generated QR code to the Downloads folder.
                    await SaveToDownloadsAsync(fileData, fileName);

                    await Application.Current.MainPage.DisplayAlert("Saved", "File saved to Downloads folder", "OK");
                }
            }
            catch (Exception ex)
            {
                // Handle exceptions and log the error.
                System.Diagnostics.Debug.WriteLine(ex);
            }
        }

        private async void ReadBarcode(object sender, EventArgs e)
        {
            try
            {
                var options = new PickOptions
                {
                    PickerTitle = "Please select a file"
                };
                var file = await FilePicker.PickAsync(options);

                OutputText.Text = "";

                if (file != null)
                {
                    using var stream = await file.OpenReadAsync();

                    BarcodeResults result;

                    if (file.ContentType.Contains("image"))
                    {
                        // Read barcodes from an image file.
                        result = BarcodeReader.Read(stream);
                    }
                    else
                    {
                        // Read barcodes from a PDF file.
                        result = BarcodeReader.ReadPdf(stream);
                    }

                    string barcodeResult = "";
                    int count = 1;

                    // Retrieve and format the barcode reading results.
                    result.ForEach(x => { barcodeResult += $"Barcode {count}: {x.Value}\n"; count++; });

                    OutputText.Text = barcodeResult;
                }
            }
            catch (Exception ex)
            {
                // Handle exceptions and log the error.
                System.Diagnostics.Debug.WriteLine(ex);
            }
        }

        public async Task SaveToDownloadsAsync(byte[] fileData, string fileName)
        {
            var downloadsPath = Android.OS.Environment.GetExternalStoragePublicDirectory(Android.OS.Environment.DirectoryDownloads);
            var filePath = Path.Combine(downloadsPath.AbsolutePath, fileName);

            try
            {
                // Create the directory if it doesn't exist.
                if (!Directory.Exists(downloadsPath.AbsolutePath))
                {
                    Directory.CreateDirectory(downloadsPath.AbsolutePath);
                }

                // Save the file to the Downloads folder.
                await File.WriteAllBytesAsync(filePath, fileData);
            }
            catch (Exception ex)
            {
                // Log errors if file saving fails.
                System.Diagnostics.Debug.WriteLine("Error saving file: " + ex.Message);
            }
        }
    }
}

using IronBarCode;
using System;
using System.IO;
using System.Threading.Tasks;
using Xamarin.Essentials;

namespace IronBarcodeMauiAndroid
{
    public partial class MainPage : ContentPage
    {
        public bool IsGeneratePdfChecked
        {
            get => generatePdfCheckBox.IsChecked;
            set
            {
                generatePdfCheckBox.IsChecked = value;
            }
        }

        public MainPage()
        {
            InitializeComponent();
            // Set the license key for IronBarcode, replace with your actual license key.
            License.LicenseKey = "IRONBARCODE-MYLICENSE-KEY-1EF01";
        }

        private async void WriteBarcode(object sender, EventArgs e)
        {
            try
            {
                if (!string.IsNullOrEmpty(barcodeInput.Text))
                {
                    // Create a barcode from the text input with the EAN13 encoding.
                    var barcode = BarcodeWriter.CreateBarcode(barcodeInput.Text, BarcodeEncoding.EAN13);

                    // Determine the file extension and data format based on the checkbox state.
                    string fileExtension = IsGeneratePdfChecked ? "pdf" : "png";
                    string fileName = $"Barcode_{DateTime.Now:yyyyMMddHHmmss}.{fileExtension}";
                    byte[] fileData = IsGeneratePdfChecked ? barcode.ToPdfBinaryData() : barcode.ToPngBinaryData();

                    // Save the generated barcode to the Downloads folder.
                    await SaveToDownloadsAsync(fileData, fileName);

                    await Application.Current.MainPage.DisplayAlert("Saved", "File saved to Downloads folder", "OK");
                }
            }
            catch (Exception ex)
            {
                // Handle exceptions and log the error.
                System.Diagnostics.Debug.WriteLine(ex);
            }
        }

        private async void WriteQRcode(object sender, EventArgs e)
        {
            try
            {
                if (!string.IsNullOrEmpty(qrInput.Text))
                {
                    // Create a QR code from the text input.
                    var barcode = QRCodeWriter.CreateQrCode(qrInput.Text);

                    // Determine the file extension and data format based on the checkbox state.
                    string fileExtension = IsGeneratePdfChecked ? "pdf" : "png";
                    string fileName = $"QRcode_{DateTime.Now:yyyyMMddHHmmss}.{fileExtension}";
                    byte[] fileData = IsGeneratePdfChecked ? barcode.ToPdfBinaryData() : barcode.ToPngBinaryData();

                    // Save the generated QR code to the Downloads folder.
                    await SaveToDownloadsAsync(fileData, fileName);

                    await Application.Current.MainPage.DisplayAlert("Saved", "File saved to Downloads folder", "OK");
                }
            }
            catch (Exception ex)
            {
                // Handle exceptions and log the error.
                System.Diagnostics.Debug.WriteLine(ex);
            }
        }

        private async void ReadBarcode(object sender, EventArgs e)
        {
            try
            {
                var options = new PickOptions
                {
                    PickerTitle = "Please select a file"
                };
                var file = await FilePicker.PickAsync(options);

                OutputText.Text = "";

                if (file != null)
                {
                    using var stream = await file.OpenReadAsync();

                    BarcodeResults result;

                    if (file.ContentType.Contains("image"))
                    {
                        // Read barcodes from an image file.
                        result = BarcodeReader.Read(stream);
                    }
                    else
                    {
                        // Read barcodes from a PDF file.
                        result = BarcodeReader.ReadPdf(stream);
                    }

                    string barcodeResult = "";
                    int count = 1;

                    // Retrieve and format the barcode reading results.
                    result.ForEach(x => { barcodeResult += $"Barcode {count}: {x.Value}\n"; count++; });

                    OutputText.Text = barcodeResult;
                }
            }
            catch (Exception ex)
            {
                // Handle exceptions and log the error.
                System.Diagnostics.Debug.WriteLine(ex);
            }
        }

        public async Task SaveToDownloadsAsync(byte[] fileData, string fileName)
        {
            var downloadsPath = Android.OS.Environment.GetExternalStoragePublicDirectory(Android.OS.Environment.DirectoryDownloads);
            var filePath = Path.Combine(downloadsPath.AbsolutePath, fileName);

            try
            {
                // Create the directory if it doesn't exist.
                if (!Directory.Exists(downloadsPath.AbsolutePath))
                {
                    Directory.CreateDirectory(downloadsPath.AbsolutePath);
                }

                // Save the file to the Downloads folder.
                await File.WriteAllBytesAsync(filePath, fileData);
            }
            catch (Exception ex)
            {
                // Log errors if file saving fails.
                System.Diagnostics.Debug.WriteLine("Error saving file: " + ex.Message);
            }
        }
    }
}

运行项目

这将向您展示如何运行项目并使用条形码功能。