// 方法 1: 显示固定行数的文本
label.frame = CGRect(x:10, y:100, width:100, height:100)label.numberOfLines = 2
label.text ="I am a label,I am a label,I am a label"//方法2:根据文字长度自己确定显示几行,只需设置numberofLines=0label.numberOfLines = 0
label.text ="I am a label,I am a label,I am a label"