C# UWP10 中 WriteableBitmap 的字节 [] 不正确
Incorrect Byte[] from WriteableBitmap in C# UWP10
我想从 WriteableBitmap 获取 base64 字符串。
我认为 byte[] 不正确。
因为:
从 base64 创建图像的代码正在运行。从文件发送 base64 字符串时测试了这一点。但是,当我使用 WriteableBitmap 到 base64 的函数时,我什么也看不到。
到目前为止我的尝试。
public static string GetByteArrayFromImage(WriteableBitmap writeableBitmap)
{
Stream stream = writeableBitmap.PixelBuffer.AsStream();
MemoryStream memoryStream = new MemoryStream();
stream.CopyTo(memoryStream);
Byte[] bytes = memoryStream.ToArray();
return Convert.ToBase64String(bytes);
}
public static string GetByteArrayFromImage(WriteableBitmap writeableBitmap)
{
Byte[] bytes = writeableBitmap.PixelBuffer.ToArray();
return Convert.ToBase64String(bytes);
}
测试示例:
public static async Task<string> GetBase64StringFromFileAsync(StorageFile storageFile)
{
Stream ms = await storageFile.OpenStreamForReadAsync();
byte[] bytes = new byte[(int)ms.Length];
ms.Read(bytes, 0, (int)ms.Length);
return Convert.ToBase64String(bytes);
}
byte[]格式有误吗?如果是,我该如何纠正?
我的新尝试
Stream stream = writeableBitmap.PixelBuffer.AsStream();
byte[] pixels = new byte[(uint)stream.Length];
await stream.ReadAsync(pixels, 0, pixels.Length);
using (var writeStream = new InMemoryRandomAccessStream())
{
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, writeStream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied, (uint)writeableBitmap.PixelWidth, (uint)writeableBitmap.PixelHeight, 96, 96, pixels);
await encoder.FlushAsync();
}
return Convert.ToBase64String(pixels);
此尝试不会将我的 byte[] 更改为正确的 fromat。
如果要将图像转换为 base64 流,最好的方法是先对其进行编码。
public static string GetByteArrayFromImage(BitmapSource writeableBitmap)
{
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(writeableBitmap));
MemoryStream stream = new MemoryStream();
encoder.Save(stream);
Byte[] bytes = stream.ToArray();
return Convert.ToBase64String(bytes);
}
public static BitmapSource GetImageFromByteArray(string base64String)
{
byte[] bytes = Convert.FromBase64String(base64String);
MemoryStream stream = new MemoryStream(bytes);
JpegBitmapDecoder decoder = new JpegBitmapDecoder(stream,
BitmapCreateOptions.None, BitmapCacheOption.Default);
return decoder.Frames[0];
}
证明其有效的测试用例:
BitmapImage originalImage = new BitmapImage(new Uri(@"Path to any picture", UriKind.Absolute));
string encoded = GetByteArrayFromImage(originalImage);
BitmapSource decoded = GetImageFromByteArray(encoded);
image1.Source = decoded;
下面的方法创建了一个在 [=12= 上运行的 BitmapEncoder
,添加了一个从 WriteableBitmap
创建的 SoftwareBitmap
,将流内容读入一个字节数组,最后将该字节数组转换为 base64 字符串:
public async Task<string> ToBase64String(WriteableBitmap writableBitmap)
{
using (var stream = new InMemoryRandomAccessStream())
{
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, stream);
encoder.SetSoftwareBitmap(SoftwareBitmap.CreateCopyFromBuffer(
writableBitmap.PixelBuffer,
BitmapPixelFormat.Bgra8,
writableBitmap.PixelWidth,
writableBitmap.PixelHeight));
await encoder.FlushAsync();
var bytes = new byte[stream.Size];
await stream.AsStream().ReadAsync(bytes, 0, bytes.Length);
return Convert.ToBase64String(bytes);
}
}
我想从 WriteableBitmap 获取 base64 字符串。 我认为 byte[] 不正确。
因为:
从 base64 创建图像的代码正在运行。从文件发送 base64 字符串时测试了这一点。但是,当我使用 WriteableBitmap 到 base64 的函数时,我什么也看不到。
到目前为止我的尝试。
public static string GetByteArrayFromImage(WriteableBitmap writeableBitmap)
{
Stream stream = writeableBitmap.PixelBuffer.AsStream();
MemoryStream memoryStream = new MemoryStream();
stream.CopyTo(memoryStream);
Byte[] bytes = memoryStream.ToArray();
return Convert.ToBase64String(bytes);
}
public static string GetByteArrayFromImage(WriteableBitmap writeableBitmap)
{
Byte[] bytes = writeableBitmap.PixelBuffer.ToArray();
return Convert.ToBase64String(bytes);
}
测试示例:
public static async Task<string> GetBase64StringFromFileAsync(StorageFile storageFile)
{
Stream ms = await storageFile.OpenStreamForReadAsync();
byte[] bytes = new byte[(int)ms.Length];
ms.Read(bytes, 0, (int)ms.Length);
return Convert.ToBase64String(bytes);
}
byte[]格式有误吗?如果是,我该如何纠正?
我的新尝试
Stream stream = writeableBitmap.PixelBuffer.AsStream();
byte[] pixels = new byte[(uint)stream.Length];
await stream.ReadAsync(pixels, 0, pixels.Length);
using (var writeStream = new InMemoryRandomAccessStream())
{
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, writeStream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied, (uint)writeableBitmap.PixelWidth, (uint)writeableBitmap.PixelHeight, 96, 96, pixels);
await encoder.FlushAsync();
}
return Convert.ToBase64String(pixels);
此尝试不会将我的 byte[] 更改为正确的 fromat。
如果要将图像转换为 base64 流,最好的方法是先对其进行编码。
public static string GetByteArrayFromImage(BitmapSource writeableBitmap)
{
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(writeableBitmap));
MemoryStream stream = new MemoryStream();
encoder.Save(stream);
Byte[] bytes = stream.ToArray();
return Convert.ToBase64String(bytes);
}
public static BitmapSource GetImageFromByteArray(string base64String)
{
byte[] bytes = Convert.FromBase64String(base64String);
MemoryStream stream = new MemoryStream(bytes);
JpegBitmapDecoder decoder = new JpegBitmapDecoder(stream,
BitmapCreateOptions.None, BitmapCacheOption.Default);
return decoder.Frames[0];
}
证明其有效的测试用例:
BitmapImage originalImage = new BitmapImage(new Uri(@"Path to any picture", UriKind.Absolute));
string encoded = GetByteArrayFromImage(originalImage);
BitmapSource decoded = GetImageFromByteArray(encoded);
image1.Source = decoded;
下面的方法创建了一个在 [=12= 上运行的 BitmapEncoder
,添加了一个从 WriteableBitmap
创建的 SoftwareBitmap
,将流内容读入一个字节数组,最后将该字节数组转换为 base64 字符串:
public async Task<string> ToBase64String(WriteableBitmap writableBitmap)
{
using (var stream = new InMemoryRandomAccessStream())
{
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, stream);
encoder.SetSoftwareBitmap(SoftwareBitmap.CreateCopyFromBuffer(
writableBitmap.PixelBuffer,
BitmapPixelFormat.Bgra8,
writableBitmap.PixelWidth,
writableBitmap.PixelHeight));
await encoder.FlushAsync();
var bytes = new byte[stream.Size];
await stream.AsStream().ReadAsync(bytes, 0, bytes.Length);
return Convert.ToBase64String(bytes);
}
}