如何通过html选择标签创建UIPickerView的对象引用 [英] How to get object referece of UIPickerView when it create through html select tag

问题描述

我有一个UIWebview包含一个htmlselect标记，它显示为屏幕。

当我点击下拉菜单时，UIWebview会自动弹出一个UIWebSelectSinglePicker视图，显示为。

我想更改选取器视图的背景颜色和文本颜色。我怎样才能达到这个目标？

我尝试在UIKeyboardWillShowNotification事件上进行侦听，但是在那个时候，这个视图还没有创建。

感谢您的帮助。

如果有人也想立即更改UIPickView，请看一看：

首先，添加UIKeyboardWillShowNotification事件监听器。

pre $ [[NSNotificationCenter defaultCenter] addObserver：self selector：@selector（_pickerViewWillBeShown :) name：UIKeyboardWillShowNotification object ：零];


第二，当通知被触发时，延迟后调用背景颜色方法。 < - 这是非常重要的，如果调用方法没有延迟，pickview在那时不存在。

   - （ void）_pickerViewWillBeShown：（NSNotification *）aNotification {
 [self performSelector：@selector（_resetPickerViewBackgroundAfterDelay）withObject：nil afterDelay：0]; 
} 
  

第三，通过UIApplication窗口找出pickerView。你可以改变你想要的pickerView。

   - （void）_resetPickerViewBackgroundAfterDelay 
 {
 UIPickerView * pickerView = nil; 
 for（UIWindow * uiWindow in [[UIApplication sharedApplication] windows]）{
 for（UIView * uiView in [uiWindow subviews]）{
 pickerView = [self _findPickerView：uiView]; 
} 
} 
 
 if（pickerView）{
 [pickerView setBackgroundColor：UIColorFromRGB（0x00FF00）]; （UIPickerView *）_findPickerView：（UIView *）uiView {
 if（[uiView isKindOfClass：[UIPickerView class]]）{$ b $ {
 
} 
 
 b返回（UIPickerView *）uiView; $ {
} 
 if（[uiView subviews] .count> 0）{
 for（UIView * subview in [uiView subviews]）{
 UIPickerView * view = [self _findPickerView：子视图]。 
 if（view）
 return view; 
} 
} 
 return nil; 
} 
  

希望这会有所帮助。

I have a UIWebview contains a html "select" tag, which is shown as a on the screen.

When I click the dropdown, the UIWebview brings up a UIWebSelectSinglePicker View automatically, which is shown as .

I want to change the picker view background color and text color. How can I achieve this goal?

I tried to listen on UIKeyboardWillShowNotification event, but at that moment, this view has not been created.

Thanks in advance for any helps.

解决方案

I managed to resolve the issue myself.

If someone also want to change the UIPickView on the fly, please take a look:

First, add a listener on UIKeyboardWillShowNotification event.

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(_pickerViewWillBeShown:) name:UIKeyboardWillShowNotification object:nil];

Second, when notification fired, call change background color method after delay. <-- This is very important, if call method without delay, the pickview does not exist at that moment.

- (void)_pickerViewWillBeShown:(NSNotification*)aNotification {
   [self performSelector:@selector(_resetPickerViewBackgroundAfterDelay) withObject:nil   afterDelay:0];
}

Third, go through the UIApplication windows and find out pickerView. And you can change what ever you want for pickerView.

-(void)_resetPickerViewBackgroundAfterDelay
{
  UIPickerView *pickerView = nil;
  for (UIWindow *uiWindow in [[UIApplication sharedApplication] windows]) {
    for (UIView *uiView in [uiWindow subviews]) {
      pickerView = [self _findPickerView:uiView];
    }
  }

  if (pickerView){
    [pickerView setBackgroundColor:UIColorFromRGB(0x00FF00)];
  }
}

(UIPickerView *) _findPickerView:(UIView *)uiView {
  if ([uiView isKindOfClass:[UIPickerView class]] ){
    return (UIPickerView*) uiView;
  }
  if ([uiView subviews].count > 0) {
    for (UIView *subview in [uiView subviews]){
      UIPickerView* view = [self _findPickerView:subview];
      if (view)
        return view;
    }
  }
  return nil;
}

Hope it will help.

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