How to set max lines for Text or RichText?

Simple using the maxLines property

Text("Some large text", maxLines: 2)

And you can use overflow: TextOverflow.ellipsis to insert ... overflow ellipsis in text

Text("Some large text", maxLines: 2, overflow: TextOverflow.ellipsis)

Edit 2021 - it's possible now

(Hint - Optional but recommended is to set some overflow with maxLines)

        Text(
          'My text',
          maxLines: 4,
          overflow: TextOverflow.ellipsis,
        ),


       RichText(
          text: TextSpan(children: ....),
          maxLines: 4,
          overflow: TextOverflow.ellipsis,
        ),

I believe it's supported now:

RichText(
    maxLines: 2,
    overflow: TextOverflow.ellipsis, // TextOverflow.clip // TextOverflow.fade
    text: TextSpan(
        text: 'Hello ',
        style: DefaultTextStyle.of(context).style,
        children: <TextSpan>[
            TextSpan(text: 'bold', style: TextStyle(fontWeight: FontWeight.bold)),
            TextSpan(text: ' world!'),
        ],
    ),
)