iOS控件學習筆記 - UITextField

初始化

UITextField *textField = [[UITextField alloc]init];
textField.frame = CGRectMake(100,100, 200,20);
textField.placeholder = @"請輸入信息";
[self.view addSubview:textField];

常用方法和屬性

常用方法和屬性	解釋
textField.placeholder = @“請輸入信息”;	設置佔位文字
textField.tintColor = [UIColor orangeColor];	設置光標顏色
textField.borderStyle = UITextBorderStyleLine;	設置邊框樣式
textField.autocorrectionType = UITextAutocorrectionTypeNo;	設置自動校正
textField.autocapitalizationType = UITextAutocapitalizationTypeAllCharacters;	設置自動大寫
textField.returnKeyType = UIReturnKeyYahoo;	設置鍵盤返回按鈕
textField.enablesReturnKeyAutomatically = YES;	設置鍵盤返回按鈕不可點(當輸入框內無文字時,返回按鈕不可點)
textField.clearButtonMode = UITextFieldViewModeWhileEditing;	設置右側全部清除按鈕
[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"]	修改textField的placeholder的字體顏色
[textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"]	修改textField的placeholder的字體大小

設置佔位文字樣式

NSMutableDictionary *dict = [NSMutableDictionary dictionary];
dict[NSForegroundColorAttributeName] = [UIColor redColor];
NSAttributedString *attrStr = [[NSAttributedString alloc]initWithString:@"佔位文字" attributes:dict];
textField.attributedPlaceholder = attrStr;

代理相關方法

- (void)textFieldDidBeginEditing:(UITextField *)textField;//開始編輯 獲取焦點
- (void)textFieldDidEndEditing:(UITextField *)textField;//結束編輯 失去焦點
- (BOOL)textFieldShouldReturn:(UITextField *)textField;//點擊鍵盤返回按鈕 
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string;//文本發生變化時觸發此方法

監聽UITextField的文字改變不建議使用代理, 用addTarget監聽文字改變事件。
[textField addTarget:self action:@selector(textEditingChanged) forControlEvents:UIControlEventEditingChanged];

UITextField通知

UITextFieldTextDidBeginEditingNotification //開始編輯時
UITextFieldTextDidEndEditingNotification  //結束編輯時
UITextFieldTextDidChangeNotification     //文本發生變化時

UIKeyboard通知

UIKeyboardWillShowNotification   //鍵盤顯示之前發送
UIKeyboardDidShowNotification   //鍵盤顯示之後發送
UIKeyboardWillHideNotification    //鍵盤隱藏之前發送
UIKeyboardDidHideNotification     //鍵盤隱藏之後發送

鍵盤類型

textField.keyboardType = UIKeyboardTypeNumberPad;
typedef enum {
    UIKeyboardTypeDefault,     　默認鍵盤，支持所有字符
    UIKeyboardTypeASCIICapable,　支持ASCII的默認鍵盤
    UIKeyboardTypeNumbersAndPunctuation,　標準電話鍵盤，支持＋＊＃字符
    UIKeyboardTypeURL,            URL鍵盤，支持.com按鈕 只支持URL字符
    UIKeyboardTypeNumberPad,            　數字鍵盤
    UIKeyboardTypePhonePad,　 　電話鍵盤
    UIKeyboardTypeNamePhonePad, 　電話鍵盤，也支持輸入人名
    UIKeyboardTypeEmailAddress, 　用於輸入電子 郵件地址的鍵盤
    UIKeyboardTypeDecimalPad,   　數字鍵盤 有數字和小數點
    UIKeyboardTypeTwitter,      　優化的鍵盤，方便輸入@、#字符
    UIKeyboardTypeAlphabet = UIKeyboardTypeASCIICapable,
} UIKeyboardType;

限制只能輸入特定字符

方式1

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    NSCharacterSet *cs;
    //invertedSet方法是去反字符,把所有的除了number 裏的字符都找出來(包含去空格功能)
    NSString *number = @"1234567890";
    cs = [[NSCharacterSet characterSetWithCharactersInString:number]invertedSet];
    NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs]componentsJoinedByString:@""];
    BOOL canChange = [string isEqualToString:filtered];
    return canChange;
}

方式2(正則表達式)

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    NSString* number= @"^[0-9]*$";
    NSPredicate *numberPre = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",number];
    return [numberPre evaluateWithObject:string];
}

限制輸入字符長度

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    NSString * toBeString = [textField.text stringByReplacingCharactersInRange:range withString:string];
    if ([toBeString length] > 10) {
        textField.text = [toBeString substringToIndex:10];
        return NO;
    }
    return YES;
}

點擊頁面空白處關閉鍵盤

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(viewTapped:)];
[self.view addGestureRecognizer:tap];

-(void)viewTapped:(UITapGestureRecognizer*)tap{
    [self.view endEditing:YES];
}

更多屬性 可以查看UIKit/Headers/NSAttributedString.h文件。