Windows Phone开发经验谈(15)动态的改变APP的字体大小

    虽然Windows Phone 8快要出来了...但是丝毫不能使我减少对WP7的研究...这次教大家如何动态改变APP的字体大小,想看具体的演示可以去windows phone市场下载 公交路线查询http://www.windowsphone.com/?appsid=384ba16d-d30f-44a5-9a8e-e395eea269df 

    我在公交路线查询里面设置了3种的字体大小（大，中，小） 我用一个枚举来表示

    public enum FontSizePattern
    {
        Small = 0,
        Middle,
        Large
    }

   但是大家要知道，虽然字体分为了大、中、小，但是很多地方的字体显示大小还是不一样的，所以任何一种字体大小里面还要设置不同的字体SIZE，这里我把字体大小的配置写成XAML文件

   large.xaml

<ResourceDictionary
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:sys="clr-namespace:System;assembly=mscorlib"
    >

    <sys:Double x:Key="FontSize18">22.4</sys:Double>
    <sys:Double x:Key="FontSize22">26.4</sys:Double>
    <sys:Double x:Key="FontSize24">28.8</sys:Double>
    <sys:Double x:Key="FontSize30">32.8</sys:Double>
    <sys:Double x:Key="FontSize36">43.2</sys:Double>
    <sys:Double x:Key="FontSize48">57.6</sys:Double>
    <sys:Double x:Key="FontSize60">72.0</sys:Double>
    <sys:Double x:Key="FontSize72">86.4</sys:Double>

</ResourceDictionary>

  

middle.xaml

<ResourceDictionary
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:sys="clr-namespace:System;assembly=mscorlib"
    >
    <sys:Double x:Key="FontSize18">22.0</sys:Double>
    <sys:Double x:Key="FontSize22">22.0</sys:Double>
    <sys:Double x:Key="FontSize24">24.0</sys:Double>
    <sys:Double x:Key="FontSize30">28.0</sys:Double>
    <sys:Double x:Key="FontSize36">36.0</sys:Double>
    <sys:Double x:Key="FontSize48">48.0</sys:Double>
    <sys:Double x:Key="FontSize60">60.0</sys:Double>
    <sys:Double x:Key="FontSize72">72.0</sys:Double>

</ResourceDictionary>

small.xaml

<ResourceDictionary
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:sys="clr-namespace:System;assembly=mscorlib"
    >

    <sys:Double x:Key="FontSize18">16.6</sys:Double>
    <sys:Double x:Key="FontSize22">17.6</sys:Double>
    <sys:Double x:Key="FontSize24">19.2</sys:Double>
    <sys:Double x:Key="FontSize30">23.8</sys:Double>
    <sys:Double x:Key="FontSize36">28.8</sys:Double>
    <sys:Double x:Key="FontSize48">38.4</sys:Double>
    <sys:Double x:Key="FontSize60">48.0</sys:Double>
    <sys:Double x:Key="FontSize72">57.6</sys:Double>

</ResourceDictionary>

  

现在我们要做的是用户选择不同的字体的时候加载不同的xaml文件就可以了，接下来我们来创建一个类Configuration 用来存储用户的配置信息同样用到了AppSettingHelper这个类，可以去Windows Phone开发经验谈(14)-动态的改变APP的语言里面获取...下面是Configuration的代码

using System.ComponentModel;
namespace ChinaBus.Utility
{



    public class Configuration : INotifyPropertyChanged
    {


        Configuration()
        {
       this._fontSizePattern = AppSettingHelper.GetValueOrDefault<FontSizePattern>("FontSizePattern", FontSizePattern.Small);
                this._themesPattern = AppSettingHelper.GetValueOrDefault<ThemesPattern>("ThemesPattern", ThemesPattern.Blue);

        }

        private static Configuration _instance;
        public static Configuration Instance
        {
            get
            {
                if (Configuration._instance == null)
                {
                    Configuration._instance = new Configuration();
                }
                return Configuration._instance;
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        private void OnPropertyChanged(string propertyName)
        {
            if (this.PropertyChanged != null)
            {
                this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        private ThemesPattern _themesPattern;
        public ThemesPattern ThemesPattern
        {
            get
            {
                return this._themesPattern;
            }
            set
            {
                if (this._themesPattern != value)
                {
                    this._themesPattern = value;
                    this.UpdateValue("ThemesPattern", value);
                    this.OnPropertyChanged("ThemesPattern");
                }
            }
        }
        private FontSizePattern _fontSizePattern;
        public FontSizePattern FontSizePattern
        {
            get
            {
                return this._fontSizePattern;
            }
            set
            {
                if (this._fontSizePattern != value)
                {
                    this._fontSizePattern = value;
                    this.UpdateValue("FontSizePattern", value);
                    this.OnPropertyChanged("FontSizePattern");
                }
            }
        }
        private void UpdateValue(string key, object value)
        {
            AppSettingHelper.AddOrUpdateValue(key, value);
        }

    }
}

这时候再创建一个类叫做FontSizeProvider 用来加载xaml获取各种字体的大小，下面是完整的代码。

using System;
using System.ComponentModel;
using System.Windows;
using System.IO.IsolatedStorage;

namespace ChinaBus.Utility
{
    public class FontSizeProvider : INotifyPropertyChanged
    {
        private double _fontSize18;
        private double _fontSize22;
        private double _fontSize24;
        private double _fontSize30;
        private double _fontSize36;
        private double _fontSize48;
        private double _fontSize60;
        private double _fontSize72;
        public event PropertyChangedEventHandler PropertyChanged;
        public double F18
        {
            get
            {
                return this._fontSize18;
            }
            private set
            {
                if (this._fontSize18 != value)
                {
                    this._fontSize18 = value;
                    if (this.PropertyChanged != null)
                    {
                        this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("F18"));
                    }
                }
            }
        }
        public double F22
        {
            get
            {
                return this._fontSize22;
            }
            private set
            {
                if (this._fontSize22 != value)
                {
                    this._fontSize22 = value;
                    if (this.PropertyChanged != null)
                    {
                        this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("F22"));
                    }
                }
            }
        }
        public double F24
        {
            get
            {
                return this._fontSize24;
            }
            private set
            {
                if (this._fontSize24 != value)
                {
                    this._fontSize24 = value;
                    if (this.PropertyChanged != null)
                    {
                        this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("F24"));
                    }
                }
            }
        }

        public double F30
        {
            get
            {
                return this._fontSize30;
            }
            private set
            {
                if (this._fontSize30 != value)
                {
                    this._fontSize30 = value;
                    if (this.PropertyChanged != null)
                    {
                        this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("F30"));
                    }
                }
            }
        }
        public double F36
        {
            get
            {
                return this._fontSize36;
            }
            private set
            {
                if (this._fontSize36 != value)
                {
                    this._fontSize36 = value;
                    if (this.PropertyChanged != null)
                    {
                        this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("F36"));
                    }
                }
            }
        }
        public double F48
        {
            get
            {
                return this._fontSize48;
            }
            private set
            {
                if (this._fontSize48 != value)
                {
                    this._fontSize48 = value;
                    if (this.PropertyChanged != null)
                    {
                        this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("F48"));
                    }
                }
            }
        }
        public double F60
        {
            get
            {
                return this._fontSize60;
            }
            private set
            {
                if (this._fontSize60 != value)
                {
                    this._fontSize60 = value;
                    if (this.PropertyChanged != null)
                    {
                        this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("F60"));
                    }
                }
            }
        }
        public double F72
        {
            get
            {
                return this._fontSize72;
            }
            private set
            {
                if (this._fontSize72 != value)
                {
                    this._fontSize72 = value;
                    if (this.PropertyChanged != null)
                    {
                        this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("F72"));
                    }
                }
            }
        }
        public FontSizeProvider()
        {
            this.ApplyPattern();
            Configuration.Instance.PropertyChanged += new PropertyChangedEventHandler(this.Configuration_PropertyChanged);
        }
        private void Configuration_PropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            if (string.Compare(e.PropertyName, "FontSizePattern", StringComparison.OrdinalIgnoreCase) == 0)
            {
                this.ApplyPattern();
            }
        }
        ~FontSizeProvider()
        {
            Configuration.Instance.PropertyChanged -= new PropertyChangedEventHandler(this.Configuration_PropertyChanged);
        }
        private void ApplyPattern()
        {
            FontSizePattern fontSizePattern = Configuration.Instance.FontSizePattern;
            string text = string.Format("/ChinaBus;component/Themes/Fonts/{0}.xaml", fontSizePattern.ToString());
            ResourceDictionary resourceDictionary = new ResourceDictionary();
            Application.LoadComponent(resourceDictionary, new Uri(text, UriKind.Relative));
            this.F18 = (double)resourceDictionary["FontSize18"];
            this.F22 = (double)resourceDictionary["FontSize22"];
            this.F24 = (double)resourceDictionary["FontSize24"];
            this.F30 = (double)resourceDictionary["FontSize30"];
            this.F36 = (double)resourceDictionary["FontSize36"];
            this.F48 = (double)resourceDictionary["FontSize48"];
            this.F60 = (double)resourceDictionary["FontSize60"];
            this.F72 = (double)resourceDictionary["FontSize72"];
        }


    }



}

这时候你在app.xaml加入下面代码

    <utility:FontSizeProvider x:Key="FontSizeProvider"/>

这样你就可以在xaml里面使用，代码如下

    <TextBlock Text="{Binding BusDescription}"
                                                       TextWrapping="Wrap"
                                                       Margin="0,0,50,0"  Foreground="{Binding Path=BusForeground, Source={StaticResource ThemeProvider}}" 
                                                       FontSize="{Binding Path=F18, Source={StaticResource FontSizeProvider}}" 

当然在CS文件里面也同样可以使用，你可以用单例模式来实现..也可以每次都创建一个类来实现，代码如下

  FontSizeProvider fzp = new FontSizeProvider();
  var tbBacklineInfo = new TextBlock();
            tbBacklineInfo.TextWrapping = TextWrapping.Wrap;
            tbBacklineInfo.Text = info.BackLine;
            tbBacklineInfo.FontSize = fzp.F30;

好了..介绍完了...有什么问题欢迎留言讨论！