//leveraging the extension functions
fun TextView.makeBold(){
    this.setTypeface(this.typeface,Typeface.BOLD)
}


yourTextView.makeBold()

最好的方法是在styles.xml中定义它

<style name="common_txt_style_heading" parent="android:style/Widget.TextView">
        <item name="android:textSize">@dimen/common_txtsize_heading</item>
        <item name="android:textColor">@color/color_black</item>
        <item name="android:textStyle">bold|italic</item>
</style>

在TextView中更新

  <TextView
     android:id="@+id/txt_userprofile"
     style="@style/common_txt_style_heading"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:layout_centerHorizontal="true"
     android:layout_marginTop="@dimen/margin_small"
     android:text="@string/some_heading" />

正如这里所解释的，如果你需要在你的样式文本资源中使用参数，你必须转义开括号

<resources>
<string name="welcome_messages">Hello, %1$s! You have &lt;b>%2$d new messages&lt;/b>.</string>
</resources>

然后调用formatHtml(string)

Resources res = getResources();
String text = String.format(res.getString(R.string.welcome_messages), username, mailCount);
CharSequence styledText = Html.fromHtml(text);

你可以这样做:

myTextView.setTypeface(null, Typeface.ITALIC);
myTextView.setTypeface(null, Typeface.BOLD_ITALIC);
myTextView.setTypeface(null, Typeface.BOLD);
myTextView.setTypeface(null, Typeface.NORMAL);

如果你想保留之前的字体，不想失去之前应用的字体，那么另一个选择:

myTextView.setTypeface(textView.getTypeface(), Typeface.NORMAL);      
myTextView.setTypeface(textView.getTypeface(), Typeface.BOLD);        
myTextView.setTypeface(textView.getTypeface(), Typeface.ITALIC);      
myTextView.setTypeface(textView.getTypeface(), Typeface.BOLD_ITALIC); 

AppCompatTextView text =(AppCompatTextView)findViewById(R.layout.appCompatTextView1);
text.setTypeface(null,Typeface.BOLD);

使用上述方法以编程方式设置字体。

TextView text = (TextView)findViewById(R.id.THE_TEXTVIEW_ID);

现在设置textview属性..

text.setTypeface(null, Typeface.BOLD);  //-- for only bold the text
text.setTypeface(null, Typeface.BOLD_ITALIC);  //-- for  bold & italic the text
text.setTypeface(null, Typeface.ITALIC);  // -- for  italic the text