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This article mainly introduces how to use UITextField in ios, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

/ / initialize textfield and set the location and size

UITextField * text = [[UITextField alloc] initWithFrame:CGRectMake (20,20,130,30)]

/ / set the border style, which will be displayed only if it is set.

Text.borderStyle = UITextBorderStyleRoundedRect

Typedef enum {

UITextBorderStyleNone

UITextBorderStyleLine

UITextBorderStyleBezel

UITextBorderStyleRoundedRect

} UITextBorderStyle

/ / sets the background color of the input box, which is set to white if the custom background picture frame is used, it will be ignored

Text.backgroundColor = [UIColor whiteColor]

/ / set the background

Text.background = [UIImage paired walled picpathNamedsaw @ "dd.png"]

/ / set the background

Text.disabledBackground = [UIImage paired walled picpathNamedsaw @ "cc.png"]

/ / when there is no content in the input box, the watermark prompt indicates that the content is password

Text.placeholder = @ "password"

/ / sets the font style and size of the input box content

Text.font = [UIFont fontWithName:@ "Arial" size:20.0f]

/ / set font color

Text.textColor = [UIColor redColor]

/ / whether there is a cross in the input box, and when it is displayed, it is used to delete the contents of the input box at once.

Text.clearButtonMode = UITextFieldViewModeAlways

Typedef enum {

UITextFieldViewModeNever, whether or not to appear again

UITextFieldViewModeWhileEditing, appears when editing

UITextFieldViewModeUnlessEditing, appears except for editors.

UITextFieldViewModeAlways keeps showing up.

} UITextFieldViewMode

/ / text that has been in the input box since the beginning.

Text.text = @ "text in the input box from the beginning"

/ / every time you enter a character, it becomes a point phrase, password input.

Text.secureTextEntry = YES

/ / whether to correct errors or not

Text.autocorrectionType = UITextAutocorrectionTypeNo

Typedef enum {

UITextAutocorrectionTypeDefault, default

UITextAutocorrectionTypeNo, no automatic error correction

UITextAutocorrectionTypeYes, automatic error correction

} UITextAutocorrectionType

/ / empty it if you edit it again

Text.clearsOnBeginEditing = YES

/ / content alignment

Text.textAlignment = UITextAlignmentLeft

/ / Vertical alignment of content UITextField inherits from UIControl, and there is an attribute contentVerticalAlignment in this class

Text.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter

/ / when set to YES, the text automatically shrinks to fit the size of the text window. The default is to keep the original size and let the long text scroll

TextFied.adjustsFontSizeToFitWidth = YES

/ / sets the minimum font size for automatic reduction of the display

Text.minimumFontSize = 20

/ / set the keyboard style

Text.keyboardType = UIKeyboardTypeNumberPad

Typedef enum {

UIKeyboardTypeDefault, default keyboard, supports all characters

UIKeyboardTypeASCIICapable, which supports the default keyboard of ASCII

UIKeyboardTypeNumbersAndPunctuation, standard phone keypad, supports + * # characters

UIKeyboardTypeURL, URL keyboard, .com buttons only support URL characters

UIKeyboardTypeNumberPad, numeric keypad

UIKeyboardTypePhonePad, phone keypad

UIKeyboardTypeNamePhonePad, phone keypad, also supports entering names

UIKeyboardTypeEmailAddress, keyboard for entering email addresses

UIKeyboardTypeDecimalPad, numeric keypad with numbers and decimal points

UIKeyboardTypeTwitter, optimized keyboard for easy input of @ and # characters

UIKeyboardTypeAlphabet = UIKeyboardTypeASCIICapable

} UIKeyboardType

/ / whether the initials are capitalized

Text.autocapitalizationType = UITextAutocapitalizationTypeNone

Typedef enum {

UITextAutocapitalizationTypeNone, do not capitalize automatically

UITextAutocapitalizationTypeWords, the first letter of the word is capitalized

UITextAutocapitalizationTypeSentences, the first letter of a sentence is capitalized

UITextAutocapitalizationTypeAllCharacters, all letters are capitalized

} UITextAutocapitalizationType

/ / what is the key changed to?

Text.returnKeyType = UIReturnKeyDone

Typedef enum {

UIReturnKeyDefault, default gray button, marked Return

UIReturnKeyGo, the blue button marked Go

UIReturnKeyGoogle, marked with the blue button Google, the term search

UIReturnKeyJoin, the blue button marked Join

UIReturnKeyNext, the blue button marked Next

UIReturnKeyRoute, the blue button marked Route

UIReturnKeySearch, the blue button marked Search

UIReturnKeySend, the blue button marked Send

UIReturnKeyYahoo, the blue button marked Yahoo

UIReturnKeyYahoo, the blue button marked Yahoo

UIReturnKeyEmergencyCall, emergency call button

} UIReturnKeyType

/ / Keyboard appearance

TextView.keyboardAppearance=UIKeyboardAppearanceDefault

Typedef enum {

UIKeyboardAppearanceDefault, default appearance, light gray

UIKeyboardAppearanceAlert, dark gray and graphite

} UIReturnKeyType

/ / set the proxy to implement the protocol

Text.delegate = self

/ / add textfield to the view

[self.window addSubview:text]

/ / the image on the far right is similar to the left side of the following code

UIImageView * paired picpathic = [[UIImageView alloc] initWithImage: [UIImage paired wrought picpathNamedRod @ "right.png"]]

Text.rightView=p_w_picpath

Text.rightViewMode = UITextFieldViewModeAlways

Typedef enum {

UITextFieldViewModeNever

UITextFieldViewModeWhileEditing

UITextFieldViewModeUnlessEditing

UITextFieldViewModeAlways

} UITextFieldViewMode

/ / press the return key to press down the keyboard to becomeFirstResponder

The class should adopt the UITextFieldDelegate protocol

Text.delegate = self; declares that I am the proxy for text, and I'm going to implement the keyboard down method, which is in UITextFieldDelegate, so we're going to use UITextFieldDelegate.

-(BOOL) textFieldShouldReturn: (UITextField *) textField

{

[text resignFirstResponder]; / / it is mainly that where [receiver resignFirstResponder] is called, the keyboard corresponding to the receiver can be lowered.

Return YES

}

Override drawing behavior

In addition to the style options of the UITextField object, you can also customize the UITextField object and add many different rewriting methods to change the display behavior of the text field. Each of these methods returns a CGRect structure that defines the bounds of each part of the text field. The following methods can be overridden.

-textRectForBounds: / / rewrite to reset the text area

-drawTextInRect: / / change the emoji attribute. When rewriting, you can call super to draw according to the default graphic properties. If you completely rewrite the drawing function, you don't have to call super.

-placeholderRectForBounds: / / rewrite to reset the placeholder area

-drawPlaceholderInRect: / / override changes the drawing placeholder property. When rewriting, you can call super to draw according to the default graphic properties. If you completely rewrite the drawing function, you don't have to call super.

-borderRectForBounds: / / rewrite to reset the edge area

-editingRectForBounds: / / rewrite to reset the editing area

-clearButtonRectForBounds: / / rewrite to reset the clearButton position. Changing the size may cause distortion of the button image.

-leftViewRectForBounds:

-rightViewRectForBounds:

Entrusting method

-(BOOL) textFieldShouldBeginEditing: (UITextField *) textField {

/ / returns a Bool value that specifies whether the sequential text field starts editing

Return YES;

}

-(void) textFieldDidBeginEditing: (UITextField *) textField {

/ / triggered when editing starts, the text field will become first responder

}

-(BOOL) textFieldShouldEndEditing: (UITextField *) textField {

/ / returns the Bool value, specifying whether to allow the text field to end editing. When the editing is finished, the text field will give up first responder.

/ / to prevent the text field from disappearing when the user ends editing, you can return NO

/ / this is useful for programs where text fields must always be active, such as instant messaging

Return NO;

}

-(BOOL) textField: (UITextField*) textField shouldChangeCharactersInRange: (NSRange) range replacementString: (NSString *) string {

This method is called when the user uses the autocorrect function to change the input text to the recommended text.

/ / this is especially useful for applications that want to add the undo option

/ / you can track the last changes made in the field, or log all edits for audit purposes.

/ / to prevent the text from being changed, return NO.

/ / there is a NSRange object in the parameter of this method, which indicates the location of the changed text, and the proposed modified text is also in it.

Return YES;

}

-(BOOL) textFieldShouldClear: (UITextField *) textField {

/ / returns a Bool value indicating whether content is allowed to be cleared according to the user's request.

/ / can be set to clear content under specific conditions

Return YES;

}

-(BOOL) textFieldShouldReturn: (UITextField *) textField {

/ / returns a Bool value indicating whether editing is allowed to end when the enter key is pressed

/ / if the resignFirstResponder method is allowed to be called, this will cause editing to end and the keyboard will be folded [textField resignFirstResponder]

/ / look up the meaning of the word resign to understand this method.

Return YES;

}

Notice

UITextField is derived from UIControl, so the notification system in the UIControl class can also be used in text fields. In addition to the standard events of the UIControl class, you can also use the following events specific to the UITextField class

UITextFieldTextDidBeginEditingNotification

UITextFieldTextDidChangeNotification

UITextFieldTextDidEndEditingNotification

Triggered when a text field exits edit mode. The object property of the notification stores the final text.

Because the text field uses the keyboard to enter text, action notifications are also sent when the following events occur

Send before UIKeyboardWillShowNotification / / keyboard display

Send after UIKeyboardDidShowNotification / / keyboard display

Sent before UIKeyboardWillHideNotification / / Keyboard is hidden

Send after UIKeyboardDidHideNotification / / Keyboard is hidden

1. Text: sets the default text of the text box.

2. Placeholder: you can display gray words in the text box to prompt the user what to enter in this text box. When data is entered in this text box, the gray word used for the prompt will automatically disappear.

3 、 Background:

4. Disabled: if selected, the user will not be able to change the contents of the text box.

5. Then there are three buttons to set the alignment.

6. Border Style: select the boundary style.

7. Clear Button: this is a drop-down menu. You can choose when the clear button appears. The so-called clear button is a small X to the right of the text box. You can have the following choices:

7.1 Never appears: never show up

7.2 Appears while editing: appears when editing

7.3 Appears unless editing:

7.4 Is always visible: always visible

8. Clear when editing begins: if selected, the previous contents of the text box will be erased when you start editing the text box. For example, if you type "What" in this text box A, and then edit text box B, if you come back to edit text box A, the "What" will be cleared immediately.

9. Text Color: sets the color of the text in the text box.

10. Font: sets the font and font size of the text.

11. Min Font Size: set the minimum font that the text box can display (but I don't think it's useful)

12. Adjust To Fit: specifies whether the text in the text box should also be reduced when the size of the text box decreases. Select it to make all the text visible, even if the text is long. But this option should be used with Min Font Size, and no matter how small the text is, it will not be less than the set Min Font Size.

The next section is used to set how the keyboard is displayed.

13. Captitalization: set uppercase. There are four options in the drop-down menu:

13.1 None: do not set uppercase

13.2 Words: the first letter of each word is capitalized, and the word here refers to a string separated by spaces

13.3 Sentances: the first letter of each sentence is capitalized, and the sentence here is a string separated by a period plus a space

13.4 All Characters: so uppercase letters

14. Correction: check spelling. Default is YES.

15. Keyboard: select the keyboard type, such as all numbers, letters, numbers, etc.

16 、 Appearance:

17. Return Key: select the return key. You can select Search, Return, Done, etc.

18. Auto-enable Return Key: if selected, the return key of the keyboard will be valid only after you enter at least one character in the text box.

19. Secure: you can select this option when your text box is used as a password input box, and the character is displayed as an asterisk.

1.Alignment Horizontal horizontal alignment

2.Alignment Vertical vertical alignment

3. Used to return whether a Bool value input box is Selected (checked) Enabled (available) Highlighted (highlighted)

Limit input to specific characters

(BOOL) textField: (UITextField *) textField shouldChangeCharactersInRange: (NSRange) range replacementString: (NSString *) string {

NSCharacterSet * cs

Cs = [[NSCharacterSet characterSetWithCharactersInString:NUMBERS] invertedSet]

NSString * filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@ "]; / / separate the array by cs, and the array by @"

BOOL canChange = [string isEqualToString:filtered]

Return canChange

}

The NUMBERS above is a macro that can be defined at the top of the file:

# define NUMBERS @ "0123456789n" (this representative can enter numbers and line breaks, please pay attention to this n, if you do not write this, the Done button will not be triggered, if it is used in SearchBar, it will not trigger the Search event, because you do not allow you to enter n, so sad, I found it in the project. )

So, if you want to restrict the input of English and numbers, you can define this as:

# define kAlphaNum @ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789".

Of course, you can also make a prompt before the above method return, such as prompting the user to enter only numbers and so on. If you think you need it.

Limit input to characters of a certain length

-(BOOL) textField: (UITextField *) textField shouldChangeCharactersInRange: (NSRange) range replacementString: (NSString *) string

{/ / string is the character textField entered at this time, which is the input box that is being typed at this time. If you return YES, you can change the value NO of the input box.

If ([string isEqualToString:@ "n"]) / / Press the car to change

{

Return YES

}

NSString * toBeString = [textField.text stringByReplacingCharactersInRange:range withString:string]; / / get the contents of the input box

If (self.myTextField = = textField) / / the input box that we want to limit when determining whether or not

{

If ([toBeString length] > 20) {/ / if the content of the input box is greater than 20, a warning pops up

TextField.text = [toBeString substringToIndex:20]

UIAlertView * alert = [UIAlertView alloc] initWithTitle:nil message:@ "cannot enter" delegate:nil cancelButtonTitle:@ "Ok" otherButtonTitles:nil, nil] autorelease beyond the maximum number of words]

[alert show]

Return NO

}

}

Return YES

}

Thank you for reading this article carefully. I hope the article "how to use UITextField in ios" shared by the editor will be helpful to everyone. At the same time, I also hope you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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