如何绑定到WPF的ProgressBar-Visibility元素？我无法将它绑定到字符串属性，因为它采用了一个具有三个选项的枚举：Collapsed、Visible和Hidden。请为ProgressBar的绑定可见性显示可理解的代码。提前谢谢。
<Grid Width="150" Margin="30,0" Visibility="{Binding ProgressBarVisibility}">
<ProgressBar Width="150" Height="Auto" HorizontalAlignment="Stretch" Foreground="#FF01D328"
Minimum="-3" Maximum="100" Value="{Binding DownloadPercentage, Mode=OneWay}" />
<TextBlock Text="Downloading" HorizontalAlignment="Center" />
</Grid>
在视图模型中：
public Visibility ProgressBarVisibility
{
get
{
return (DownloadingPdf && DownloadPercentage < 100) ? Visibility.Visible : Visibility.Collapsed;
}
}
private int mDownloadPercentage;
public int DownloadPercentage
{
get { return mDownloadPercentage; }
set
{
if (mDownloadPercentage==value)
{
return;
}
else
{
mDownloadPercentage = Math.Min(Math.Abs(value), 100);
OnPropertyChanged("DownloadPercentage");
OnPropertyChanged("DownloadProgressBarVisibility");
}
}
}