Question

我正在Xamarin中创建一个应用程序。我想使用自动滚动功能，但我无法以正确的方式执行此操作。我可以手动滚动。我想要自动显示下一张图片而不滚动。请分享您的观点和代码。

我现在使用滑块。但我想知道我是否可以做得更好。

        Grid SliderGrid = new Grid ();
        //SliderGrid.BackgroundColor = Color.Black;
        //SliderGrid.Padding = 10;
        int SlidercolumnCount = Slider.Count;
        RowDefinition Sliderrow = new RowDefinition ();         
        SliderGrid.RowDefinitions.Add (Sliderrow);
        for (int j = 0; j < SlidercolumnCount; j++) {
            ColumnDefinition col = new ColumnDefinition ();
            SliderGrid.ColumnDefinitions.Add (col);
        }
        for (int i = 0; i < SlidercolumnCount; i++) {
            var vetImageCol = new Image {
                HeightRequest=260,
                WidthRequest=360,
                BindingContext = Slider [i],
                Source = Slider [i].CategoryImage,
                Aspect=Aspect.AspectFill,
            };
            Grid.SetColumn (vetImageCol, i);        
            SliderGrid.Children.Add (vetImageCol);
        }
        var SliderContent = new ScrollView {
            Orientation=ScrollOrientation.Horizontal,
            HorizontalOptions=LayoutOptions.FillAndExpand,
            //HeightRequest=265,
            Content= SliderGrid,
        };

Answer 1

使用像这样的任务命令可以做到这一点：

`using(Webclient webclient = new Webclient())
   {
     webClient http = new Webclient();
     http.Credentials = new NetworkCredential("YourUsername", "YourPassword");
    }

尽管使用Task返回值而不是void可以做得更好但是你明白了

Answer 2

    //page view is may ui scroll view 
    //counter for if my image focus on last image then return on 1 img 
    //new PointF((float)(your image size * count),your top margin or your fram y);

    int count = 0;
                public async void StartTimer()
                {
                    await Task.Delay(3000); //3 sec 

                    count += 1;
                    if (count == 5)
                    {
                        count = 0;
                    }
                    var bottomOffset = new PointF((float)(UIScreen.MainScreen.Bounds.Width * count),0);
                    pageview.SetContentOffset(bottomOffset, animated: true);
                    StartTimer();          


                }


public override void ViewDidLoad(){
 StartTimer();  
}

在Xamarin中创建自动滚动

2 个答案: