iOS UIView SizeToFit sizethatfits

UILabel *testlabel = [[UILabel alloc] Initwithframe:cgrectmake (ten, 0, 0)];    Testlabel.backgroundcolor = [Uicolor whitecolor];    Testlabel.text = @ "We all have a home, the name is China, the house is climbing two dragons";    Testlabel.font = [Uifont systemfontofsize:20];    Testlabel.textcolor = [Uicolor blackcolor];    [TestLabel Sizethatfits:cgsizemake (20, 20)];//calculates the optimal size but does not change its size, and the individual thinks that this is the label's adaptive size and nothing else is useful    NSLog (@ " TestLabel sizethatfits frame =%@ ", Nsstringfromcgrect (Testlabel.frame));    NSLog (@ "Best size =%@", nsstringfromcgsize ([TestLabel sizethatfits:cgsizemake (+)]));    [TestLabel sizetofit];//calculates the optimal size and changes its size    NSLog (@ "TestLabel sizetofit frame =%@", Nsstringfromcgrect ( Testlabel.frame));
    [Self.view  Addsubview:testlabel];

iOS UIView SizeToFit sizethatfits