無法更改文本

Question

我已經建立2個UITextField S和UIButton編程爲UITextField的，當我點擊UIButton我希望它改變突出UITextField的文本，但它改變第二UITextField的文本不突出一。

-(void)viewDidLoad 
{ 
    txtf = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 586, 45)]; 
    txtf.borderStyle = UITextBorderStyleNone; 
    txtf.backgroundColor = [UIColor clearColor]; 
    txtf.font = [UIFont systemFontOfSize:17]; 
    txtf.autocorrectionType = UITextAutocorrectionTypeNo; 
    txtf.keyboardType = UIKeyboardTypeDefault; 
    txtf.returnKeyType = UIReturnKeyDone; 
    txtf.textAlignment = NSTextAlignmentLeft; 
    txtf.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter; 
    [self.view addSubview:txtf]; 

    txtf = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 586, 345)]; 
    txtf.borderStyle = UITextBorderStyleNone; 
    txtf.backgroundColor = [UIColor clearColor]; 
    txtf.font = [UIFont systemFontOfSize:17]; 
    txtf.autocorrectionType = UITextAutocorrectionTypeNo; 
    txtf.keyboardType = UIKeyboardTypeDefault; 
    txtf.returnKeyType = UIReturnKeyDone; 
    txtf.textAlignment = NSTextAlignmentLeft; 
    txtf.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter; 
    [self.view addSubview:txtf]; 
} 

- (IBAction)change:(id)sender 
{ 
    txtf.text = @"the text was changed" 
} 

有沒有辦法解決這個問題？

Answer 1

更改您的代碼

-(void)viewDidLoad{ 
txtf1 = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 586, 45)]; 
txtf1.borderStyle = UITextBorderStyleNone; 
txtf1.backgroundColor = [UIColor clearColor]; 
txtf1.font = [UIFont systemFontOfSize:17]; 
txtf1.autocorrectionType = UITextAutocorrectionTypeNo; 
txtf1.keyboardType = UIKeyboardTypeDefault; 
txtf1.returnKeyType = UIReturnKeyDone; 
txtf1.textAlignment = NSTextAlignmentLeft; 
txtf1.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter; 
[self.view addSubview:txtf1]; 

txtf2 = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 586, 345)]; 
txtf2.borderStyle = UITextBorderStyleNone; 
txtf2.backgroundColor = [UIColor clearColor]; 
txtf2.font = [UIFont systemFontOfSize:17]; 
txtf2.autocorrectionType = UITextAutocorrectionTypeNo; 
txtf2.keyboardType = UIKeyboardTypeDefault; 
txtf2.returnKeyType = UIReturnKeyDone; 
txtf2.textAlignment = NSTextAlignmentLeft; 
txtf2.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter; 
[self.view addSubview:txtf2]; 
} 

- (IBAction)change:(id)sender { 
txtf2.text = @"the text was changed" 
} 

並添加txtf2類成員。

UPDATE：
要更改突出UITextField修改- (IBAction)change:(id)sender到

- (IBAction)change:(id)sender 
{ 
    if (txtf1.isHighlighted) { 
     txtf1.text = @"the text 1 was changed"; 
    } 
    else if (txtf2.isHighlighted) { 
     txtf2.text = @"the text 2 was changed"; 
    } 
    else { 
     NSLog(@"none of the textField is Highlighted"); 
    } 
} 

更新2 當你有很多的文本字段，你可以嘗試以下

for (id subview in self.view.subviews) { 
    if ([subview isKindOfClass:[UITextField class]]) { 
     UITextField *textField = subview; 
     if (textField.isHighlighted) { 
      textField.text = @"the text was changed"; 
     } 
    } 
} 

Answer 2

txtf總是指向第二個textField。所以這個問題。

當您創建第一個UItextFied時，txtf指向它。但是，當您創建一個新的UITextField並使txtf指向它時，然後引用第一個文本字段丟失。

而在你的change方法，你總是得到reference of second textfield並改變它。

兩個選項，
1）使用txtf1和txtf2，二級性質
2）使用標籤。 [UIView viewWithTag:tagValue];

使用Tag's->
假設numberOfTextFields您使用爲3

txtf = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 586, 45)]; 
//set its properties 
txtf.tag=1; 
[self.view addSubview:txtf]; 

txtf = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 586, 45)]; 
//set its properties 
txtf.tag=2; 
[self.view addSubview:txtf]; 

txtf = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 586, 45)]; 
//set its properties 
txtf.tag=3; 
[self.view addSubview:txtf]; 

修改變化的方法來

- (IBAction)change:(id)sender 
{ 
    NSInteger numberOfTextFields=3; 
    UITextField *textField; 
    for (int i=1; i<=numberOfTextFields; i++) { 
     textField=(UITextField*)[self.view viewWithTag:i]; 
     if(textField.isHighlighted==YES) 
      break; 
     else 
      textField=nil; 
    } 

    if(textField==nil){ 
     NSLog(@"none is highlightes"); 
    } 
    else{ 
     textField.text= @"new text for highlighted textField"; 
    } 
} 

Answer 3

因爲你既UITextField具有相同的名稱（ txtf），因此首先更改第一個或第二個UITextField的名稱。其他方面你的代碼是正確的。 :)

編輯：

只是要更正確@ AVT的更新的答案。

- (IBAction)change:(id)sender 
{ 
    if (txtf1.isHighlighted) { 
     txtf1.text = @"the text 1 was changed"; 
    } 
    else if (txtf2.isHighlighted) { 
     txtf2.text = @"the text 2 was changed"; 
    } 
    else { 
     NSLog(@"none of the textField is Highlighted"); 
    } 
}