IOS UI 代码创建UIButton，UITextField，UILabel

//add a Label

UILabel *label=[[UILabelalloc]initWithFrame:CGRectMake(100,20, 150, 40)];

[label setText:@"i am a label "];

label.font=[UIFontsystemFontOfSize:20];

label.textAlignment=NSTextAlignmentLeft;

//文字内容自适应标签宽度

label.adjustsFontSizeToFitWidth=YES;

[self.viewaddSubview:label];

//add a button

UIButton *button=[UIButtonbuttonWithType:UIButtonTypeRoundedRect];

[button setFrame:CGRectMake(100,300, 150, 40)];

[button setTitle:@"i am a button"forState:UIControlStateNormal];

//[button addTarget:selfaction:@selector(makeAnotherButton:)forControlEvents:UIControlEventTouchUpInside];

[self.viewaddSubview:button];

//add a textField

UITextField *textField=[[UITextFieldalloc] initWithFrame:CGRectMake(100,150, 150, 40)];

//[textField setText:@"i am atextField"];

//只是显示password这个标识

textField.placeholder=@"password";

//密码编辑显示圆点PASSWORD

textField.secureTextEntry=YES;

//再次对textField编辑时清除内容

textField.clearsOnBeginEditing=YES;

//当编辑的时候才有clearButton

textField.clearButtonMode=UITextFieldViewModeWhileEditing;

//默认键盘

textField.keyboardType=UIKeyboardTypeDefault;

//边框样式这个我觉得最好看

textField.borderStyle=UITextBorderStyleRoundedRect;

textField.textColor=[UIColorblueColor];

[self.viewaddSubview:textField];