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" />

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

保持以前的字体

textView.setTypeface(textView.getTypeface(), Typeface.BOLD_ITALIC)

基于样式选择标准，最简单的方法是:

String pre = "", post = "";

if(isBold){
    pre += "<b>"; post += "</b>";
}
if(isItalic){
    pre += "<i>"; post += "</i>";
}
if(isUnderline){
    pre += "<u>"; post += "</u>";
}

textView.setText(Html.fromHtml(pre + editText.getText().toString()+ post));
// you can also use it with EidtText
editText.setText(Html.fromHtml(pre + editText.getText().toString()+ post));

编程:

你可以通过编程方式使用setTypeface()方法:

下面是默认字体的代码

textView.setTypeface(null, Typeface.NORMAL);      // for Normal Text
textView.setTypeface(null, Typeface.BOLD);        // for Bold only
textView.setTypeface(null, Typeface.ITALIC);      // for Italic
textView.setTypeface(null, Typeface.BOLD_ITALIC); // for Bold and Italic

如果你想设置自定义字体:

textView.setTypeface(textView.getTypeface(), Typeface.NORMAL);      // for Normal Text
textView.setTypeface(textView.getTypeface(), Typeface.BOLD);        // for Bold only
textView.setTypeface(textView.getTypeface(), Typeface.ITALIC);      // for Italic
textView.setTypeface(textView.getTypeface(), Typeface.BOLD_ITALIC); // for Bold and Italic

XML:

你可以直接在<TextView />的XML文件中设置如下:

android:textStyle="normal"
android:textStyle="normal|bold"
android:textStyle="normal|italic"
android:textStyle="bold"
android:textStyle="bold|italic"

或者你可以设置你最喜欢的字体(从资产)。欲了解更多信息，请参阅链接

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


yourTextView.makeBold()