UITextFieldDelegate協議，uitextfielddelegate

UITextFieldDelegate協議，uitextfielddelegate

 

很多人都認為UITextField很簡單，為什麼會寫這個協議呢？

因為在實際開發中可能會用到；

 

比如要做到的效果：

文字框下面的底線的顏色要隨著輸入的狀態變化；

點擊對應的文字框，其下面的線條變為綠色，結束編輯，變為灰色；

要熟悉UITextFieldDelegate協議才能做到這一點；

首先，先看一下官方的說明：

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField;        // return NO to disallow editing.- (void)textFieldDidBeginEditing:(UITextField *)textField;           // became first responder- (BOOL)textFieldShouldEndEditing:(UITextField *)textField;          // return YES to allow editing to stop and to resign first responder status. NO to disallow the editing session to end- (void)textFieldDidEndEditing:(UITextField *)textField;             // may be called if forced even if shouldEndEditing returns NO (e.g. view removed from window) or endEditing:YES called- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string;   // return NO to not change text- (BOOL)textFieldShouldClear:(UITextField *)textField;               // called when clear button pressed. return NO to ignore (no notifications)- (BOOL)textFieldShouldReturn:(UITextField *)textField;              // called when 'return' key pressed. return NO to ignore.

 

1、

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

文字框已經開始編輯

2、

- (void)textFieldDidEndEditing:(UITextField *)textField; 

文字框已經結束編輯

 

3、其他設定是否允許的輸入控制

1、- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField;        // return NO to disallow editing.
   //控制是否允許輸入，傳回值是NO的時候，禁止輸入；

2、- (BOOL)textFieldShouldEndEditing:(UITextField *)textField;          // return YES to allow editing to stop and to resign first responder status. NO to disallow the editing session to end   //是否結束輸入，傳回值是YES時候，允許停止輸入，並且釋放第一響應；返回NO的時候，則相反；3、- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string;   // return NO to not change text
    //是否改變輸入文本，返回NO的時候，不儲存修改
4、- (BOOL)textFieldShouldClear:(UITextField *)textField;               // called when clear button pressed. return NO to ignore (no notifications)
   //當清空按鈕時候調用，返回是NO的時候，忽視清空
5、- (BOOL)textFieldShouldReturn:(UITextField *)textField;              // called when 'return' key pressed. return NO to ignore.

   //當點擊return按鈕時候調用該方法，返回是NO的時候，不做任何響應；