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我們需要對我們的網頁漸變,所以我們使用SkiaSharp和GradientView。這在Android上正常工作,但不適用於iOS - 漸變只是不顯示。Xamarin.Forms SkiaSharp梯度工作在Android上而不是在iOS
我們需要做任何具體的iOS,初始化爲SkiaSharp在iOS上,用在AppDelegate的渲染器或代碼?
編輯這是在iPad與iOS 10.3.3運行。 我們的XAML:
<?xml version="1.0" encoding="utf-8" ?>
<ContentView xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="MyProject.XForms.Controls.GradientView">
</ContentView>
我們XAML.cs
using SkiaSharp;
using SkiaSharp.Views.Forms;
using Xamarin.Forms;
namespace MyProject.XForms.Controls
{
public partial class GradientView : ContentView
{
public Color StartColor { get; set; } = Color.Transparent;
public Color EndColor { get; set; } = Color.Transparent;
public bool Horizontal { get; set; } = false;
public GradientView()
{
InitializeComponent();
SKCanvasView canvasView = new SKCanvasView();
canvasView.PaintSurface += OnCanvasViewPaintSurface;
Content = canvasView;
}
void OnCanvasViewPaintSurface(object sender, SKPaintSurfaceEventArgs args)
{
SKImageInfo info = args.Info;
SKSurface surface = args.Surface;
SKCanvas canvas = surface.Canvas;
canvas.Clear();
var colors = new SKColor[] { StartColor.ToSKColor(), EndColor.ToSKColor() };
SKPoint startPoint = new SKPoint(0, 0);
SKPoint endPoint = Horizontal ? new SKPoint(info.Width, 0) : new SKPoint(0, info.Height);
var shader = SKShader.CreateLinearGradient(startPoint, endPoint, colors, null, SKShaderTileMode.Clamp);
SKPaint paint = new SKPaint
{
Style = SKPaintStyle.Fill,
Shader = shader
};
canvas.DrawRect(new SKRect(0, 0, info.Width, info.Height), paint);
}
}
}
謝謝,這很有趣。我創建了一個空白的新項目,並且它現在也不在Android上工作。通過它進行調試,我可以看到Control的OnCanvasViewPaintSurface方法永遠不會被調用。據推測,我在我的XAML或其他地方缺少一些東西來觸發此事。 –
您必須確保畫布大小不是0x0。什麼是佈局/容器?您可能必須在漸變視圖上設置大小或佈局選項。 – Matthew
我試過設置佈局/大小選項,但沒有區別。如果我給控制檯顯示一個背景顏色。但我明白,這不一定與畫布大小有關 –