自定义UITextField委托设置为self启动无限循环 [英] Custom UITextField delegate set to self initiates infinite loop

问题描述

我正在编写iPhone App，我需要自定义UITextField类。对于我的文本字段，我需要缩进，图像在文本和最大字符之前。出于这个原因，我创建了基于UITextField的自定义类。我的所有文本字段都将基于这个新类。我使用Google并搜索了Stackoverflow，我发现在像我这样的情况下我必须在 init self.delegate = self; $ c>所以我不需要在我的View Controller类中实现像 textFieldShouldBeginEditing 或 textFieldShouldEndEditing 这样的方法。我的所有文本字段都将在故事板中创建，因此 initWithCoder 。因此，在输入1,2或3个符号后，我收到无限循环和App崩溃（此刻我使用模拟器）。有趣的是，对于数字键盘或密码键盘，没有这样的问题。此外，如果我在我的Mac键盘上而不是在模拟器上键入符号，则没有问题。我试图调试，但在崩溃期间它直接跳转到循环并存在错误。
如何克服这个问题？

I am writing iPhone App in which I need custom UITextField class. For my text fields I need indent, image inside before the text and max characters. For this reason I created custom class based on UITextField. All my text fields will be based on this new class. I use Google and searched Stackoverflow and I find that in cases like mine I have to use self.delegate = self; during the init so I don't need to implement methods like textFieldShouldBeginEditing or textFieldShouldEndEditing inside my View Controller class. All my text fields will be created in storyboard so initWithCoder. As a result I receive infinite loop and App crash (I use simulator at this moment) after typing 1, 2 or 3 symbols. It is interesting that for numeric keyboard or password keyboard there is no such issue. Also if I type symbols on my Mac keyboard instead on the simulator there is no problem. I tried to debug but during the crash it jumps directly into loop and exist with error. How to overcome this problem?

P.S。我问了问题当我收到无限循环并且有评论 self.delegate = self; 会导致这样的循环，但我看到这个语句被广泛使用。可能是我没有正确地做到这一点，但我无法弄清楚如何从UITextField中创建可重用的类。

P.S. I asked question when I receive infinite loop and there was comments that self.delegate = self; can cause such loop, but I see that this statement is widely used. May be I did not do this correctly, but I can not figure out how to make reusable class out of UITextField.

编辑：
这是我的代码：

Here is my code:

On inti我初始化并设置边框颜色：

On inti I initialize and set border color:

- (id)initWithCoder:(NSCoder *)aDecoder{
    self = [super initWithCoder:aDecoder];
    if (self) {

        self.layer.borderColor=[[UIColor blackColor] CGColor];
        self.delegate = self;
    }
    return self;
}

当我开始编辑时，我改变边框颜色并设置缩进（缩进设置将是移动到属性设置器中）：

When I start edit I change border color and set indent (indent set will be moved in property setter):

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

    // Change border of text field that is editing to orange
    textField.layer.masksToBounds=YES;
    textField.layer.borderColor=[[UIColor orangeColor] CGColor];
    textField.layer.borderWidth= 1.0f;

    UIView *spacerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, _leftIndent, 10)];
    [self setLeftViewMode:UITextFieldViewModeAlways];
    [self setLeftView:spacerView];

    return YES;
}

完成编辑后我返回颜色：

On finish editing I return back color:

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

    // Change border of text field that is edited to black
    textField.layer.masksToBounds=YES;
    textField.layer.borderColor=[[UIColor blackColor] CGColor];
    textField.layer.borderWidth= 1.0f;

    return YES;
}

在价值变化时，我检查最多字符：

And on value change I check max characters:

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

    // Restrict number of symbols in text field to "maxSymbols"
    NSUInteger oldLength = [textField.text length];
    NSUInteger replacementLength = [string length];
    NSUInteger rangeLength = range.length;

    NSUInteger newLength = oldLength - rangeLength + replacementLength;

    BOOL returnKey = [string rangeOfString: @"\n"].location != NSNotFound;

    return newLength <= (int)_maxSymbols || returnKey;
}

推荐答案

我不知道是否这可以是实际答案，但我已经解决了下一个问题的答案如何在iOS中正确地继承了UITextField？（来自 justafinger ）。我没有在我的自定义控件中进行分配 self.delegate = self; ，但我有从视图控制器中的委托调用的方法。

I don't know if this can be actual answer, but I have work around which is the answer of my next question How properly subclass UITextField in iOS? (from justafinger). I don't make assignment self.delegate = self; in my custom control, but I have methods that are called from delegates in view controller.

我希望这可以帮助像我一样有问题的人。

I hope this can help people with problem like mine.

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