Question

我有ViewView的ListView表示来自WebService的数据。我在来自WebService的数据中有布尔标志，根据该标志我需要更改ViewCell文本的颜色。如果flag为True，则设置颜色为红色，否则为白色。怎么做？

我的ListView和ViewCell如下：

ListView listof_datewiseRecord = new ListView { 
    BackgroundColor=ColorResources.PageBackgroundColor,
    ItemTemplate = new DataTemplate (typeof(dataCell)),
    ItemsSource = listofdate,
    RowHeight=70,
};
public class dataCell:ViewCell
    {
        public dataCell ()
        {
            var date = new Label () {
                FontFamily = "HelveticaNeue-Medium",
                FontSize = 13,
                TextColor = ColorResources.TextColor,
                VerticalOptions = LayoutOptions.CenterAndExpand,
                HorizontalOptions = LayoutOptions.Start
            };
            date.SetBinding (Label.TextProperty, "date");

            var day = new Label (){ 
                FontFamily = "HelveticaNeue-Medium",
                FontSize = 13,
                TextColor = ColorResources.TextColor,
                VerticalOptions = LayoutOptions.CenterAndExpand,
                HorizontalOptions = LayoutOptions.Start
            };
            day.SetBinding (Label.TextProperty,"weekday");

            var date_and_day = new StackLayout {
                VerticalOptions = LayoutOptions.CenterAndExpand,
                HorizontalOptions = LayoutOptions.Start,
                WidthRequest=90,
                Children={
                    date,
                    day
                }
            };

            var inTime = new Label () {
                FontFamily = "HelveticaNeue-Medium",
                FontSize = 13,
                WidthRequest=60,
                TextColor = ColorResources.TextColor,
                VerticalOptions = LayoutOptions.CenterAndExpand,
                HorizontalOptions = LayoutOptions.Start
            };
            inTime.SetBinding (Label.TextProperty,"In");


            var outTime = new Label () {
                FontFamily = "HelveticaNeue-Medium",
                WidthRequest=60,
                FontSize = 13,
                TextColor = ColorResources.TextColor,
                VerticalOptions = LayoutOptions.CenterAndExpand,
                HorizontalOptions = LayoutOptions.Start
            };
            outTime.SetBinding (Label.TextProperty,"Out");

            var totalTime = new Label () {
                FontFamily = "HelveticaNeue-Medium",
                WidthRequest=60,
                FontSize = 13,
                TextColor = ColorResources.TextColor,
                VerticalOptions = LayoutOptions.CenterAndExpand,
                HorizontalOptions = LayoutOptions.Start
            };
            totalTime.SetBinding (Label.TextProperty, "totalInTime");


            var btnDetails = new Image () {             
                WidthRequest=40,
                HeightRequest=40,
                BackgroundColor=Color.Black,
                Source="info.png",
                VerticalOptions = LayoutOptions.Center,
                HorizontalOptions = LayoutOptions.Center
            };



            var cellLayout = new StackLayout {
                Spacing = 5,
                Padding = new Thickness (5, 5, 5, 5),
                Orientation = StackOrientation.Horizontal,
                HorizontalOptions = LayoutOptions.FillAndExpand,
                Children = {
                    date_and_day,
                    inTime,
                    outTime,
                    totalTime,
                    btnDetails
                }
            };
            this.View = cellLayout; 
        }
    }

在ListView中加载数据的模型如下：

public class DateWiseData
    {
        public string _Date { get; set; }
        public List<DateData> dateData { get; set; }
    }
    public class DateData
    {
        public string uid { get; set; }
        public string employeeName { get; set; }
        public string _date { get; set; }
        public string fin { get; set; }
        public string fout { get; set; }
        public string weekday { get; set; }
        public string totalInTime { get; set; }
        public Boolean Is_Loc_Device_Changed { get; set; }
    }

如果Is_Loc_Device_Changed设置为True，那么我需要将ViewCell的所有标签更改为红色，否则为白色或保持不变。提前谢谢！

Answer 1

您想要的是使用converter

Simple example：

public class InvertBoolenConverter : IValueConverter
{
    public object Convert (object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (value is bool) 
        {
            return !(bool)value;
        }
        return value;
}

    public object ConvertBack (object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
    throw new NotImplementedException ();
    }
}

在你的绑定代码中：

runtime.SetBinding(Label.TextProperty,new Binding("Runtime", BindingMode.Default,
    new InvertBoolenConverter(), null));

或者在xaml。

根据Xamarin中的布尔值绑定Label的TextColor

1 个答案: