Uno平台:加载嵌入式资源文件

Question

如何为Android头部加载嵌入式资源?下面的代码适用于UWP:

Assembly assembly = GetType ().GetTypeInfo ().Assembly;
string[] names = assembly.GetManifestResourceNames ();
Console.WriteLine ("Resource Names");
foreach (var name in names)
Console.WriteLine ("  " + name);
using (var stream = assembly.GetManifestResourceStream (Source))
{
bmpSrc = SKBitmap.Decode (stream);
}

XAML是

<controls:ExpandableImage 
...
Source="UnoTest.Assets.icons.folder_tab.png"
/>

该文件位于UnoTest.Shared/Assets/中，标记为"嵌入式资源"。

调试输出显示其中一个"名称">

"UnoTest.Droid.Assets.icons.folder_tab.png"

表示我的URI应该指向Android头部。

编辑最终，在这个实验中，我打算在目标区域的左侧绘制位图的左侧部分，在右侧绘制右侧部分，并用位图中部的垂直条纹扩展填充中间部分。然后，在上面画一些文字。

private void OnPaintSurface(object sender, SKPaintSurfaceEventArgs e)
{
...
// identify left, right halves and a 10px wide swath of the middle of the source bitmap
SKRect rectSrcLeft = new SKRect(0, 0, bmpSrc.Width / 2, bmpSrc.Height);
SKRect rectSrcRight = new SKRect(bmpSrc.Width / 2, 0, bmpSrc.Width, bmpSrc.Height);
SKRect rectSrcMid = new SKRect(bmpSrc.Width / 2 - 5, 0, bmpSrc.Width / 2 + 5, bmpSrc.Height);
// create a new bitmap containing a 10 pixel wide swatch from middle of bmpSrc
SKBitmap bmpSrcMid = new SKBitmap(10, bmpSrc.Height);
using (SKCanvas tempCanvas = new SKCanvas(bmpSrcMid))
{
SKRect rectDest = new SKRect(0, 0, rectSrcMid.Width, rectSrcRight.Height);
tempCanvas.DrawBitmap(bmpSrc, rectSrcMid, rectDest);
}
var canvas = e.Surface.Canvas;
using (SKPaint paint = new SKPaint())
{
canvas.Save();
float hDest = canvas.DeviceClipBounds.Height;
float scale = hDest / (float)bmpSrc.Height;
canvas.Scale(scale);
paint.IsAntialias = true;
// determine dest rect for middle section
float rightDest = (float)textBounds.Width / scale; // rightmost point of whole target area
SKRect rectDestMid = new SKRect(rectSrcLeft.Width, 0, rightDest - rectSrcRight.Width, rectSrcRight.Height);
// left part of tab
canvas.DrawBitmap(bmpSrc, rectSrcLeft, rectSrcLeft, paint);
// right part of tab
{
SKRect rectDest = new SKRect(rectDestMid.Right, 0, rightDest, rectSrcRight.Height);
canvas.DrawBitmap(bmpSrc, rectSrcRight, rectDest, paint);
}
// mid part of tab
paint.Shader = SKShader.CreateBitmap(bmpSrcMid,
SKShaderTileMode.Repeat,
SKShaderTileMode.Repeat);
canvas.DrawRect(rectDestMid, paint);
canvas.Restore(); // back to orig scale
}
using (SKPaint paint = new SKPaint { Color = SKColors.Black })
{
float leftText = 20; // matches padding in ListPage.xaml
float bottomText = canvas.DeviceClipBounds.Height / 2 + textCoreHeight / 2;
canvas.DrawText(Label, new SKPoint(leftText, bottomText), paint);
}
}

控件的XAML是:

<UserControl
x:Class="UnoTest.Shared.Controls.ExpandableImage"
...
<skia:SKXamlCanvas x:Name="EICanvas" PaintSurface="OnPaintSurface" />
</UserControl>

我需要写一些代码来修改"泛型"吗?Android的URI ?

Answer 1

在共享项目中定义的嵌入式资源共享了引用该共享项目的项目的默认命名空间，使得Uno模板中默认所有项目的文件名都不同。

你有多个选项:

• 将所有项目的默认命名空间更改为相同
• 跳过前两个点，并使用它作为基础
• 使用一个不同的项目(一个。net标准2.0项目就可以)并把你的资源放在那里

Answer 2

我最后是这样做的。它不是100%健壮，但非常接近。这真的很简单。

if (Source == null)
return;
string sourceWithNameSpace = null;
Assembly assembly = GetType ().GetTypeInfo ().Assembly;
string[] names = assembly.GetManifestResourceNames ();
foreach (var name in names)
{
if (name.EndsWith (Source))
{
sourceWithNameSpace = name;
break;
}
}
if (sourceWithNameSpace == null)
return;
using (var stream = assembly.GetManifestResourceStream (sourceWithNameSpace))
{
bmpSrc = SKBitmap.Decode (stream);
}

并且，在XML文件中，从源路径中去掉项目头，例如:

Source="Assets.icons.folder_tab.png"