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


yourTextView.makeBold()

TextView text = (TextView)findViewById(R.layout.textName);
text.setTypeface(null,Typeface.BOLD);

使用textView。setTypeface(字体tf, int风格);设置TextView的样式属性。有关更多信息，请参阅开发人员文档。

试试这个:

TextView textview = (TextView)findViewById(R.id.textview_idname);
textview.setTypeface(null,Typeface.BOLD);

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); 

您可以使用下面给出的示例设置不同的字体-

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

或者如果你想设置一个不同的字体和它的字体。将其添加到资产或原始文件夹，然后像这样使用它

  Typeface face= Typeface.createFromAsset(getAssets(), "font/font.ttf");
  tv1.setTypeface(face);

  Typeface face1= Typeface.createFromAsset(getAssets(), "font/font1.ttf");
  tv2.setTypeface(face1);