自定义BusyIndicator控件

因为项目中Syncfusion的BusyIndicator控件存在bug，所以实现一个较为简单的自定义BusyIndicator。

1. 创建Style

        <Style TargetType="local:CustomBusyIndicator">
            <Setter Property="Background" Value="White"/>
            <Setter Property="Foreground" Value="SkyBlue"/>
            <Setter Property="BorderThickness" Value="2"/>
            <Setter Property="BorderBrush" Value="Red"/>
            <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
            <Setter Property="VerticalContentAlignment" Value="Stretch"/>
            <Setter Property="Padding" Value="1"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="local:CustomBusyIndicator">
                        <Border x:Name="PART_Border" 
                                BorderBrush="{TemplateBinding BorderBrush}"
                                BorderThickness="{TemplateBinding BorderThickness}"
                                Background="{TemplateBinding Background}"
                                SnapsToDevicePixels="true">
                            <Grid>
                                <ContentPresenter x:Name="PART_ContentPresenter" 
                                                  Focusable="False"
                                                  HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                                  Margin="{TemplateBinding Padding}" 
                                                  RecognizesAccessKey="True" 
                                                  Content="{TemplateBinding Content}"
                                                  ContentTemplate="{TemplateBinding ContentTemplate}"
                                                  SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" 
                                                  VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                                <Grid x:Name="PART_BusyIndicator"
                                      Focusable="False"
                                      Background="#88FFFFFF"
                                      HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                                      SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" 
                                      VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
                                    <StackPanel Orientation="Vertical"
                                                HorizontalAlignment="Center"
                                                VerticalAlignment="Center">
                                        <TextBlock Text="{TemplateBinding BusyContent}"
                                                   Foreground="Red"
                                                   FontSize="30"/>
                                        <Button x:Name="PART_CancelButton"
                                                HorizontalAlignment="Center"
                                                Content="Cancel"/>
                                    </StackPanel>
                                </Grid>
                            </Grid>
                        </Border>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsBusy" Value="false">
                                <Setter Property="Visibility"
                                        TargetName="PART_BusyIndicator"
                                        Value="Collapsed"/>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

2. 创建cs

public class CustomBusyIndicator : Control
    {
        private const string PART_CancelButton = "PART_CancelButton";

        private Button innerCancelButton;

        public event RoutedEventHandler CancelClick;

        static CustomBusyIndicator()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(CustomBusyIndicator), new FrameworkPropertyMetadata(typeof(CustomBusyIndicator)));
        }

        #region BusyContent

        public string BusyContent
        {
            get { return (string)GetValue(BusyContentProperty); }
            set { SetValue(BusyContentProperty, value); }
        }

        public static readonly DependencyProperty BusyContentProperty =
            DependencyProperty.Register("BusyContent",
            typeof(string),
            typeof(CustomBusyIndicator),
            new PropertyMetadata(""));

        #endregion

        #region IsBusy

        public bool IsBusy
        {
            get { return (bool)GetValue(IsBusyProperty); }
            set { SetValue(IsBusyProperty, value); }
        }

        public static readonly DependencyProperty IsBusyProperty =
            DependencyProperty.Register("IsBusy",
            typeof(bool),
            typeof(CustomBusyIndicator),
            new PropertyMetadata(false));

        #endregion

        #region Content

        public object Content
        {
            get { return (object)GetValue(ContentProperty); }
            set { SetValue(ContentProperty, value); }
        }

        public static readonly DependencyProperty ContentProperty =
            DependencyProperty.Register("Content",
            typeof(object),
            typeof(CustomBusyIndicator),
            new PropertyMetadata(null));

        #endregion

        #region ContentTemplate

        public DataTemplate ContentTemplate
        {
            get { return (DataTemplate)GetValue(ContentTemplateProperty); }
            set { SetValue(ContentTemplateProperty, value); }
        }

        public static readonly DependencyProperty ContentTemplateProperty =
            DependencyProperty.Register("ContentTemplate",
            typeof(DataTemplate),
            typeof(CustomBusyIndicator),
            new PropertyMetadata(null));

        #endregion

        public override void OnApplyTemplate()
        {
            base.OnApplyTemplate();
            if (innerCancelButton != null)
            {
                innerCancelButton.Click -= InnerCancelButton_Click;
            }
            innerCancelButton = this.GetTemplateChild(PART_CancelButton) as Button;
            if (innerCancelButton != null)
            {
                innerCancelButton.Click += InnerCancelButton_Click;
            }
        }

        private void InnerCancelButton_Click(object sender, RoutedEventArgs e)
        {
            if (this.IsBusy)
            {
                this.IsBusy = false;
            }
            if (this.CancelClick != null)
            {
                this.CancelClick(this, e);
            }
        }
    }