为什么使用不同的输入类型？

键盘输入的类型帮助我们从用户获取必需的输入。

它移除不需要的键，并包括所需的部分。用户可以通过使用 UITextField 的键盘属性设置输入的类型。

如：文本字段（ textField）。 keyboardType = UIKeyboardTypeDefault

键盘输入类型

输入的类型	描述
UIKeyboardTypeASCIICapable	键盘包括所有标准的 ASCII 字符。
UIKeyboardTypeNumbersAndPunctuation	键盘显示数字和标点。
UIKeyboardTypeURL	键盘的 URL 项优化。
UIKeyboardTypeNumberPad	键盘用于 PIN 输入和显示一个数字键盘。
UIKeyboardTypePhonePad	键盘对输入电话号码进行了优化。
UIKeyboardTypeNamePhonePad	键盘用于输入姓名或电话号码。
UIKeyboardTypeEmailAddress	键盘对输入电子邮件地址的优化。
UIKeyboardTypeDecimalPad	键盘用来输入十进制数字。
UIKeyboardTypeTwitter	键盘对 twitter @ 和 # 符号进行了优化。

添加自定义方法 addTextFieldWithDifferentKeyboard

-(void) addTextFieldWithDifferentKeyboard{

   UITextField *textField1= [[UITextField alloc]initWithFrame: 
   CGRectMake(20, 50, 280, 30)];
   textField1.delegate = self;
   textField1.borderStyle = UITextBorderStyleRoundedRect;
   textField1.placeholder = @"Default Keyboard";
   [self.view addSubview:textField1];

   UITextField *textField2 = [[UITextField alloc]initWithFrame:
   CGRectMake(20, 100, 280, 30)];
   textField2.delegate = self;
   textField2.borderStyle = UITextBorderStyleRoundedRect;
   textField2.keyboardType = UIKeyboardTypeASCIICapable;
   textField2.placeholder = @"ASCII keyboard";
   [self.view addSubview:textField2];

   UITextField *textField3 = [[UITextField alloc]initWithFrame:
   CGRectMake(20, 150, 280, 30)];
   textField3.delegate = self;
   textField3.borderStyle = UITextBorderStyleRoundedRect;
   textField3.keyboardType = UIKeyboardTypePhonePad;
   textField3.placeholder = @"Phone pad keyboard";
   [self.view addSubview:textField3];

   UITextField *textField4 = [[UITextField alloc]initWithFrame:
   CGRectMake(20, 200, 280, 30)];
   textField4.delegate = self;
   textField4.borderStyle = UITextBorderStyleRoundedRect;
   textField4.keyboardType = UIKeyboardTypeDecimalPad;
   textField4.placeholder = @"Decimal pad keyboard";
   [self.view addSubview:textField4];

   UITextField *textField5= [[UITextField alloc]initWithFrame:
   CGRectMake(20, 250, 280, 30)];
   textField5.delegate = self;
   textField5.borderStyle = UITextBorderStyleRoundedRect;
   textField5.keyboardType = UIKeyboardTypeEmailAddress;
   textField5.placeholder = @"Email keyboard";
   [self.view addSubview:textField5];

   UITextField *textField6= [[UITextField alloc]initWithFrame:
   CGRectMake(20, 300, 280, 30)];
   textField6.delegate = self;
   textField6.borderStyle = UITextBorderStyleRoundedRect;
   textField6.keyboardType = UIKeyboardTypeURL;
   textField6.placeholder = @"URL keyboard";
   [self.view addSubview:textField6];
}

在 ViewController.m 中更新 viewDidLoad，如下所示

(void)viewDidLoad
{
   [super viewDidLoad];
   //The custom method to create textfield with different keyboard input
   [self addTextFieldWithDifferentKeyboard];
   //Do any additional setup after loading the view, typically from a nib
}

输出

现在当我们运行应用程序时我们就会得到下面的输出:

选择不同的文本区域我们将看到不同的键盘。