所以我想在android中更改android:fontFamily,但我在android中没有看到任何预定义的字体。如何选择预定义的选项之一?我真的不需要定义我自己的TypeFace,但我所需要的是与现在显示的不同。

<TextView
    android:id="@+id/HeaderText"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="52dp"
    android:gravity="center"
    android:text="CallerBlocker"
    android:textSize="40dp"
    android:fontFamily="Arial"
 />

看来我在上面做的事真的行不通!BTW android:fontFamily=“Arial”是一个愚蠢的尝试!


当前回答

在最近的一个项目中,我不得不解析/system/etc/fonts.xml。以下是截至Lollipop的当前字体系列:

╔════╦════════════════════════════╦═════════════════════════════╗
║    ║ FONT FAMILY                ║ TTF FILE                    ║
╠════╬════════════════════════════╬═════════════════════════════╣
║  1 ║ casual                     ║ ComingSoon.ttf              ║
║  2 ║ cursive                    ║ DancingScript-Regular.ttf   ║
║  3 ║ monospace                  ║ DroidSansMono.ttf           ║
║  4 ║ sans-serif                 ║ Roboto-Regular.ttf          ║
║  5 ║ sans-serif-black           ║ Roboto-Black.ttf            ║
║  6 ║ sans-serif-condensed       ║ RobotoCondensed-Regular.ttf ║
║  7 ║ sans-serif-condensed-light ║ RobotoCondensed-Light.ttf   ║
║  8 ║ sans-serif-light           ║ Roboto-Light.ttf            ║
║  9 ║ sans-serif-medium          ║ Roboto-Medium.ttf           ║
║ 10 ║ sans-serif-smallcaps       ║ CarroisGothicSC-Regular.ttf ║
║ 11 ║ sans-serif-thin            ║ Roboto-Thin.ttf             ║
║ 12 ║ serif                      ║ NotoSerif-Regular.ttf       ║
║ 13 ║ serif-monospace            ║ CutiveMono.ttf              ║
╚════╩════════════════════════════╩═════════════════════════════╝

以下是解析器(基于FontListParser):

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import android.util.Xml;

/**
 * Helper class to get the current font families on an Android device.</p>
 * 
 * Usage:</p> {@code List<SystemFont> fonts = FontListParser.safelyGetSystemFonts();}</p>
 */
public final class FontListParser {

    private static final File FONTS_XML = new File("/system/etc/fonts.xml");

    private static final File SYSTEM_FONTS_XML = new File("/system/etc/system_fonts.xml");

    public static List<SystemFont> getSystemFonts() throws Exception {
        String fontsXml;
        if (FONTS_XML.exists()) {
            fontsXml = FONTS_XML.getAbsolutePath();
        } else if (SYSTEM_FONTS_XML.exists()) {
            fontsXml = SYSTEM_FONTS_XML.getAbsolutePath();
        } else {
            throw new RuntimeException("fonts.xml does not exist on this system");
        }
        Config parser = parse(new FileInputStream(fontsXml));
        List<SystemFont> fonts = new ArrayList<>();

        for (Family family : parser.families) {
            if (family.name != null) {
                Font font = null;
                for (Font f : family.fonts) {
                    font = f;
                    if (f.weight == 400) {
                        break;
                    }
                }
                SystemFont systemFont = new SystemFont(family.name, font.fontName);
                if (fonts.contains(systemFont)) {
                    continue;
                }
                fonts.add(new SystemFont(family.name, font.fontName));
            }
        }

        for (Alias alias : parser.aliases) {
            if (alias.name == null || alias.toName == null || alias.weight == 0) {
                continue;
            }
            for (Family family : parser.families) {
                if (family.name == null || !family.name.equals(alias.toName)) {
                    continue;
                }
                for (Font font : family.fonts) {
                    if (font.weight == alias.weight) {
                        fonts.add(new SystemFont(alias.name, font.fontName));
                        break;
                    }
                }
            }
        }

        if (fonts.isEmpty()) {
            throw new Exception("No system fonts found.");
        }

        Collections.sort(fonts, new Comparator<SystemFont>() {

            @Override
            public int compare(SystemFont font1, SystemFont font2) {
                return font1.name.compareToIgnoreCase(font2.name);
            }

        });

        return fonts;
    }

    public static List<SystemFont> safelyGetSystemFonts() {
        try {
            return getSystemFonts();
        } catch (Exception e) {
            String[][] defaultSystemFonts = {
                    {
                            "cursive", "DancingScript-Regular.ttf"
                    }, {
                            "monospace", "DroidSansMono.ttf"
                    }, {
                            "sans-serif", "Roboto-Regular.ttf"
                    }, {
                            "sans-serif-light", "Roboto-Light.ttf"
                    }, {
                            "sans-serif-medium", "Roboto-Medium.ttf"
                    }, {
                            "sans-serif-black", "Roboto-Black.ttf"
                    }, {
                            "sans-serif-condensed", "RobotoCondensed-Regular.ttf"
                    }, {
                            "sans-serif-thin", "Roboto-Thin.ttf"
                    }, {
                            "serif", "NotoSerif-Regular.ttf"
                    }
            };
            List<SystemFont> fonts = new ArrayList<>();
            for (String[] names : defaultSystemFonts) {
                File file = new File("/system/fonts", names[1]);
                if (file.exists()) {
                    fonts.add(new SystemFont(names[0], file.getAbsolutePath()));
                }
            }
            return fonts;
        }
    }

    /* Parse fallback list (no names) */
    public static Config parse(InputStream in) throws XmlPullParserException, IOException {
        try {
            XmlPullParser parser = Xml.newPullParser();
            parser.setInput(in, null);
            parser.nextTag();
            return readFamilies(parser);
        } finally {
            in.close();
        }
    }

    private static Alias readAlias(XmlPullParser parser) throws XmlPullParserException, IOException {
        Alias alias = new Alias();
        alias.name = parser.getAttributeValue(null, "name");
        alias.toName = parser.getAttributeValue(null, "to");
        String weightStr = parser.getAttributeValue(null, "weight");
        if (weightStr == null) {
            alias.weight = 0;
        } else {
            alias.weight = Integer.parseInt(weightStr);
        }
        skip(parser); // alias tag is empty, ignore any contents and consume end tag
        return alias;
    }

    private static Config readFamilies(XmlPullParser parser) throws XmlPullParserException,
            IOException {
        Config config = new Config();
        parser.require(XmlPullParser.START_TAG, null, "familyset");
        while (parser.next() != XmlPullParser.END_TAG) {
            if (parser.getEventType() != XmlPullParser.START_TAG) {
                continue;
            }
            if (parser.getName().equals("family")) {
                config.families.add(readFamily(parser));
            } else if (parser.getName().equals("alias")) {
                config.aliases.add(readAlias(parser));
            } else {
                skip(parser);
            }
        }
        return config;
    }

    private static Family readFamily(XmlPullParser parser) throws XmlPullParserException,
            IOException {
        String name = parser.getAttributeValue(null, "name");
        String lang = parser.getAttributeValue(null, "lang");
        String variant = parser.getAttributeValue(null, "variant");
        List<Font> fonts = new ArrayList<Font>();
        while (parser.next() != XmlPullParser.END_TAG) {
            if (parser.getEventType() != XmlPullParser.START_TAG) {
                continue;
            }
            String tag = parser.getName();
            if (tag.equals("font")) {
                String weightStr = parser.getAttributeValue(null, "weight");
                int weight = weightStr == null ? 400 : Integer.parseInt(weightStr);
                boolean isItalic = "italic".equals(parser.getAttributeValue(null, "style"));
                String filename = parser.nextText();
                String fullFilename = "/system/fonts/" + filename;
                fonts.add(new Font(fullFilename, weight, isItalic));
            } else {
                skip(parser);
            }
        }
        return new Family(name, fonts, lang, variant);
    }

    private static void skip(XmlPullParser parser) throws XmlPullParserException, IOException {
        int depth = 1;
        while (depth > 0) {
            switch (parser.next()) {
            case XmlPullParser.START_TAG:
                depth++;
                break;
            case XmlPullParser.END_TAG:
                depth--;
                break;
            }
        }
    }

    private FontListParser() {

    }

    public static class Alias {

        public String name;

        public String toName;

        public int weight;
    }

    public static class Config {

        public List<Alias> aliases;

        public List<Family> families;

        Config() {
            families = new ArrayList<Family>();
            aliases = new ArrayList<Alias>();
        }

    }

    public static class Family {

        public List<Font> fonts;

        public String lang;

        public String name;

        public String variant;

        public Family(String name, List<Font> fonts, String lang, String variant) {
            this.name = name;
            this.fonts = fonts;
            this.lang = lang;
            this.variant = variant;
        }

    }

    public static class Font {

        public String fontName;

        public boolean isItalic;

        public int weight;

        Font(String fontName, int weight, boolean isItalic) {
            this.fontName = fontName;
            this.weight = weight;
            this.isItalic = isItalic;
        }

    }

    public static class SystemFont {

        public String name;

        public String path;

        public SystemFont(String name, String path) {
            this.name = name;
            this.path = path;
        }

    }
}

在您的项目中可以随意使用上面的类。例如,您可以为用户提供字体系列选择,并根据用户的喜好设置字体。

一个不完整的小例子:

final List<FontListParser.SystemFont> fonts = FontListParser.safelyGetSystemFonts();
String[] items = new String[fonts.size()];
for (int i = 0; i < fonts.size(); i++) {
    items[i] = fonts.get(i).name;
}

new AlertDialog.Builder(this).setSingleChoiceItems(items, -1, new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        FontListParser.SystemFont selectedFont = fonts.get(which);
        // TODO: do something with the font
        Toast.makeText(getApplicationContext(), selectedFont.path, Toast.LENGTH_LONG).show();
    }
}).show();

其他回答

通过使用这个,可以动态地将fontfamily设置为类似于xml中的android:fontfamily,

For Custom font:

 TextView tv = ((TextView) v.findViewById(R.id.select_item_title));
 Typeface face=Typeface.createFromAsset(getAssets(),"fonts/mycustomfont.ttf"); 
 tv.setTypeface(face);

For Default font:

 tv.setTypeface(Typeface.create("sans-serif-medium",Typeface.NORMAL));

以下是使用的默认字体系列的列表,可以通过替换双引号字符串“sans-serif medium”来使用这些字体

FONT FAMILY                    TTF FILE                    

1  casual                      ComingSoon.ttf              
2  cursive                     DancingScript-Regular.ttf   
3  monospace                   DroidSansMono.ttf           
4  sans-serif                  Roboto-Regular.ttf          
5  sans-serif-black            Roboto-Black.ttf            
6  sans-serif-condensed        RobotoCondensed-Regular.ttf 
7  sans-serif-condensed-light  RobotoCondensed-Light.ttf   
8  sans-serif-light            Roboto-Light.ttf            
9  sans-serif-medium           Roboto-Medium.ttf           
10  sans-serif-smallcaps       CarroisGothicSC-Regular.ttf 
11  sans-serif-thin            Roboto-Thin.ttf             
12  serif                      NotoSerif-Regular.ttf       
13  serif-monospace            CutiveMono.ttf              

“mycustomfont.ttf”是ttf文件。路径将在src/assets/fonts/mycustomfont.ttf中,您可以参考此默认字体系列中有关默认字体的更多信息

Android不允许您从XML布局设置自定义字体。相反,您必须将特定字体文件绑定到应用程序的assets文件夹中,并以编程方式进行设置。类似于:

TextView textView = (TextView) findViewById(<your TextView ID>);
Typeface typeFace = Typeface.createFromAsset(getAssets(), "<file name>");
textView.setTypeface(typeFace);

注意,只有在调用setContentView()后才能运行此代码。此外,Android只支持某些字体,并且应为.ttf(TrueType)或.otf(OpenType)格式。即使如此,某些字体也可能不起作用。

这是一种在Android上绝对有效的字体,如果Android不支持您的字体文件,您可以使用它来确认您的代码是否有效。

Android O更新:根据Roger的评论,这现在可以在Android O中使用XML。

它与android相同:字体。

内置字体有:

典型的桑斯衬线单空间

参见android:字体。

从Android Studio 3.0开始,它非常容易更改字体系列

使用支持库26,它将在运行Android API版本16和更高版本的设备上运行

在res目录下创建一个文件夹字体。下载你想要的字体并将其粘贴到字体文件夹中。结构应该如下所示

注意:从Android Support Library 26.0开始,您必须声明两组属性(Android:和app:),以确保在运行的设备上加载字体Api 26或更低。

现在,您可以使用

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="@font/dancing_script"
app:fontFamily="@font/dancing_script"/>

以程序方式更改

 Typeface typeface = getResources().getFont(R.font.myfont);
   //or to support all versions use
Typeface typeface = ResourcesCompat.getFont(context, R.font.myfont);
 textView.setTypeface(typeface);  

要使用styles.xml更改字体,请创建样式

 <style name="Regular">
        <item name="android:fontFamily">@font/dancing_script</item>
        <item name="fontFamily">@font/dancing_script</item>
        <item name="android:textStyle">normal</item>
 </style>

并将此样式应用于TextView

  <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    style="@style/Regular"/>

也可以创建自己的字体系列

-右键单击字体文件夹并转到“新建”>“字体资源文件”。此时将显示“新建资源文件”窗口。

-输入文件名,然后单击“确定”。新的字体资源XML将在编辑器中打开。

例如,在这里编写自己的字体系列

<font-family xmlns:android="http://schemas.android.com/apk/res/android">
    <font
        android:fontStyle="normal"
        android:fontWeight="400"
        android:font="@font/lobster_regular" />
    <font
        android:fontStyle="italic"
        android:fontWeight="400"
        android:font="@font/lobster_italic" />
</font-family>

这只是将特定的fontStyle和fontWeight映射到将用于呈现该特定变体的字体资源。fontStyle的有效值为normal或italic;fontWeight符合CSS字体权重规范

1.要更改布局中的字体族,可以编写

 <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:fontFamily="@font/lobster"/>

2.程序性改变

 Typeface typeface = getResources().getFont(R.font.lobster);
   //or to support all versions use
Typeface typeface = ResourcesCompat.getFont(context, R.font.lobster);
 textView.setTypeface(typeface);  

要更改整个应用程序的字体,请在AppTheme中添加这两行

 <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
     <item name="android:fontFamily">@font/your_font</item>
     <item name="fontFamily">@font/your_font</item>
  </style>

有关更多信息,请参阅文档,Android自定义字体教程

在某些情况下,这里有一种更简单的方法。其原理是在xml布局中添加不可见的TextVview,并在java代码中获取其typeFace。

xml文件中的布局:

<TextView
    android:text="The classic bread is made of flour hot and salty. The classic bread is made of flour hot and salty. The classic bread is made of flour hot and salty."
    android:layout_width="0dp"
    android:layout_height="0dp"
    android:fontFamily="sans-serif-thin"
    android:id="@+id/textViewDescription"/>

java代码:

myText.setTypeface(textViewSelectedDescription.getTypeface());

它对我很有用(例如在TextSwitcher中)。