iOS UITextField的基本用法

 UITextField *textField = [[UITextField alloc] init];//初始化

    textField.userInteractionEnabled = YES;//是否可用

    textField.text = @"UITextField"; //文字

    textField.delegate = self; //代理

    textField.frame = CGRectMake(100, 100, 100, 40); //大小和位置

    textField.textColor = [UIColor redColor];//  字體顏色

    textField.placeholder = @"UITextField";//提示字符

    [textField setBorderStyle:UITextBorderStyleRoundedRect]; //外框類型UITextBorderStyleRoundedRect枚舉類型

    textField.secureTextEntry = YES; //密碼框

    textField.clearButtonMode = UITextFieldViewModeWhileEditing; //編輯時會出現個修改X

    UIImageView *imgv=[[UIImageView alloc] initWithImage:[UIImage p_w_picpathNamed:@"right.png"]];

    textField.rightView=imgv;

    textField.rightViewMode = UITextFieldViewModeAlways; //右側加圖片

    textField.font = [UIFont systemFontOfSize:14.0f];//文字的大小

    textField.font = [UIFont boldSystemFontOfSize:14.0f];//文字加粗

    textField.autocapitalizationType = UITextAutocapitalizationTypeNone;  //首字母是否自動大寫

    textField.clearsOnBeginEditing = YES;    //再次編輯就清空

    textField.adjustsFontSizeToFitWidth = YES;  //設置為YES時文本會自動縮小以適應文本窗口大小.默認是保持原來大小,而讓長文本滾動

    textField.minimumFontSize = 20;   //設置自動縮小顯示的最小字體大小

    textField.keyboardType = UIKeyboardTypeNumberPad;   //設置鍵盤的樣式

    textField.backgroundColor = [UIColor grayColor];//背景顏色

    //placeholder 顏色

    //第一種

    UIColor *color = [UIColor whiteColor];

    textField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"用戶名" attributes:@{NSForegroundColorAttributeName: color}];

    //第二種

    [textField setValue:[UIColor whiteColor] forKeyPath:@"_placeholderLabel.textColor"];//_placeholderLabel.textColor這個不可以修改

    textField.returnKeyType =UIReturnKeyDone;   //return鍵變成什么鍵

    //文字上下居中

    textField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;

    //文字左右居中

    textField.textAlignment = NSTextAlignmentCenter;

  textField.keyboardAppearance=UIKeyboardAppearanceDefault;  //鍵盤外觀

    //UITextField左邊的距離

    CGRect frame = [textField frame];

    frame.size.width = 15;

    UIView *leftview = [[UIView alloc] initWithFrame:frame];

    textField.leftViewMode = UITextFieldViewModeAlways;  //左邊距為15pix

    textField.leftView = leftview;

    [textField becomeFirstResponder];//成為第一響應者

    [self.view addSubview:textField];