我创建了一个UITextView编程方式如下:messageBodyTxt=[[UITextViewalloc]initWithFrame:CGRectMake(36,204,763,251)];[messageBodyTxtsetTextColor:[UIColorcolorWithRed:0.627green:0.627blue:0.627alpha:1]];[messageBodyTxtsetBackgroundColor:[UIColorclearColor]];[messageBodyTxtsetText:@"somerandomtext"];但是，setText属性没有显示