MVVMCross十进制绑定到UITextField删除小数点 [英] MVVMCross Binding decimal to UITextField removes decimal point
问题描述
将小数绑定到UITextField不允许您放置."输入"1."时，按source即可将其剥离.我知道为什么会发生这种情况，MakeSafeValue会将其转换为十进制数，而无需输入."就可以将其读回，从而覆盖输入的Text.这似乎是一个keyup vs onblur问题，很多绑定框架都可以让您覆盖它.
Binding a decimal to a UITextField does not let you put a "." in, as you type "1.", the push to source strips it out. I get why it happens, MakeSafeValue converts it to a decimal, which gets read back out without the ".", overwriting the Text entered. This seems like a keyup vs onblur issue, which a lot of binding frameworks let you override.
我知道我可以在视图模型上绑定一个字符串，但是处理EditingDidEnd而不是EditingChanged似乎更好.这样，我可以拦截ShouldEndEditing来检查有效性.
I know I could bind a string on the view model instead, but handling the EditingDidEnd instead of EditingChanged seems better. That way I could intercept ShouldEndEditing to check validity.
我将在哪里注册绑定以覆盖MvvmCross实现?我尝试添加Setup.FillTargetFactories，但它在MVXTouchBindingBuilder.FillTargetFactories之前被调用，其中MvvmCross在其中.
Where would I register my binding to override the MvvmCross implementation? I tried adding in my Setup.FillTargetFactories, but it is called before MVXTouchBindingBuilder.FillTargetFactories where the MvvmCross one is.
我尝试了一个不同的属性名称，在我拥有的FillTargetFactories中:
I tried a different property name, in FillTargetFactories I have:
registry.RegisterPropertyInfoBindingFactory(typeof (UITextFieldTextDidEndTargetBinding), typeof (UITextField), "DidEndText");
但是当我绑定时它不起作用.
but it does not work when I bind.
set.Bind(textField).For("DidEndText").To(vm => vm.GMoney);
看起来像MvxPropertyInfoTargetBindingFactory.CreateBinding如果目标不具有该属性=则不起作用.这是否使我从MvxTargetBinding开始并创建自定义绑定?我讨厌在MvxPropertyInfoTargetBinding中重新创建大多数代码.
looks like MvxPropertyInfoTargetBindingFactory.CreateBinding does not work if the target does not have that property = makes sense. Does this leave me with starting at MvxTargetBinding and creating a custom binding? I hate to recreate most of the code in MvxPropertyInfoTargetBinding.
所以，我想这个问题是...
So, I guess the question(s) are...
- 使用我的默认UITextField绑定的语法/位置是什么?
- 如何为具有绑定语法的文本指定其他绑定?
谢谢.
推荐答案
使用我的默认UITextField绑定的语法/位置是什么?
what is the syntax/location to override the default UITextField binding with mine?
如果只想替换现有的绑定，则可以通过RegisterPropertyInfoBindingFactory扩展方法来实现.
If you want to simply replace the existing binding, then you can do this via the RegisterPropertyInfoBindingFactory extension method.
MvvmCross运行一个简单的最后注册的获胜者"系统.
MvvmCross operates a simple 'last registered wins' system.
最简单的将您的注册放在最后的位置是将其放置在Setup中InitializeLastChance的末尾:
The easiest place your registration in order that happens last is to place it at the end of InitializeLastChance in your Setup:
protected override void InitializeLastChance()
{
base.InitializeLastChance();
var factory = base.Resolve<IMvxTargetBindingFactoryRegistry>();
factory.RegisterPropertyInfoBindingFactory(
typeof(MyBindingType),
typeof(UITextField),
"Text");
}
在 https中有关于初始化/设置顺序的更多信息. ://github.com/slodge/MvvmCross/wiki/Customising-using-App-and-Setup (正在进行中).
如何为具有绑定语法的文本指定其他绑定?
how can I specify a different binding for Text with the Bind Syntax?
该行:
registry.RegisterPropertyInfoBindingFactory(
typeof (UITextFieldTextDidEndTargetBinding),
typeof (UITextField),
"DidEndText");
不起作用，因为它尝试使用名为DidEndText的属性-该属性不存在.
doesn't work because it tries to use a property called DidEndText - which doesn't exist.
解决此问题的两种可能方法是:
Two possible ways around this are:
1个子类UITextField以提供不动产
1 Subclass UITextField to provide a real property
public class MyTextField : UITextField
{
// ctors
public string MySpecialText
{
get { return base.Text; }
set { base.Text = value; }
}
}
An example of UITextField subclassing is shown in the N=33 video
2或使用基于非属性信息的绑定
对于已知的属性和事件对，这非常简单:
For known properties and event pairs this is pretty simple to do:
public class MySpecialBinding : MvxTargetBinding
{
public MySpecialBinding (UIEditField edit)
: base(edit)
{
edit.SpecialEvent += Handler;
}
protected override void Dispose(bool isDisposing)
{
if (isDisposing)
{
var text = (UITextField)Target;
if (text != null)
{
text.SpecialEvent -= Handler;
}
}
base.Dispose(isDisposing);
}
protected override void Handler(object s, EventArgs e)
{
var text = (UITextField)target;
if (text == null)
return;
FireValueChanged(text.Text);
}
public override MvxBindingMode DefaultMode
{
get { return MvxBindingMode.TwoWay; }
}
public override Type TargetType
{
get { return typeof(string); }
}
public override void SetValue(object value)
{
var text = (UITextField)target;
if (text == null)
return;
text.Text = value;
}
}
此特殊绑定可以使用RegisterCustomBindingFactory
registry.RegisterCustomBindingFactory<UITextField>(
"FooFlipper",
textField => new MySpecialBinding(textField));
之后的绑定如下:
set.Bind(textField).For("FooFlipper").To(vm => vm.GMoney);
将起作用.
除了在ViewModel中使用字符串"建议外，这种双文本转换的另一种可能的解决方法可能是使用双向值转换器.如果您的用户界面正在处理资金，则可能会坚持显示所有值的小数位.
As well as your 'use a string in the ViewModel' suggestion, another possible workaround for this double-text conversion, might be to use a two-way value converter. If your UI is handling money, this could insist on displaying decimal places for all values.
这篇关于MVVMCross十进制绑定到UITextField删除小数点的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
