ios 如何根据按钮按下重新加载/刷新 UIPickerView（使用新数据数组）？
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How do I reload/refresh the UIPickerView (with new data array) based on button press?
提问by jim4iOS
IF I wanted a picker, for states/provinces, i haven't seen an example, but I mocked up shown above, a picker for US/Can/Mex. wondering can you dynamically switch the NSMutableArray for the UIPickerView and then have it somehow reload each time you click on US/Can/Mex buttons??? How do I go about doing this. What approach do I take. Looking for someone to point a beginner for a clue in the right direction.
如果我想要一个选择器，对于州/省，我还没有看到一个例子，但我模拟了上面显示的，一个用于美国/加拿大/墨西哥的选择器。想知道您是否可以为 UIPickerView 动态切换 NSMutableArray，然后每次单击 US/Can/Mex 按钮时都以某种方式重新加载它？？？我该怎么做。我采取什么方法。寻找某人为初学者指出正确方向的线索。
回答by vikingosegundo
You will have to implement the datasource and the delegate.
您必须实现数据源和委托。
once you press a button, set an array pointer to the appropriate array.
按下按钮后，将数组指针设置为适当的数组。
than call [thePicker reloadAllComponents];
比打电话 [thePicker reloadAllComponents];
-(IBAction) usButtonPressed:(id)sender{
self.inputArray = self.usArray;
[self.thePicker reloadAllComponents];
}
-(IBAction) mexicoButtonPressed:(id)sender{
self.inputArray = self.mexicoArray;
[self.thePicker reloadAllComponents];
}
the datasource methods:
数据源方法：
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 1;
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
return [self.inputArray count];
}
the delegate methods:
委托方法：
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
return [self.inputArray objectAtIndex:row];
}
回答by Vinod Joshi
Swift: xcode 6.1
斯威夫特：xcode 6.1
// reload the component of picker (Used this inside the trigger action or button)
// 重新加载选择器的组件（在触发动作或按钮内使用）
[self.pickerControl reloadAllComponents];
回答by Juan Manuel
By calling
通过调用
thePicker.delegate = self;
again, I was able to force refresh the pickerview with new info
再次，我能够用新信息强制刷新选择器视图
回答by Enamul Haque
In swift 3,4,or 5 you just write in didSelectRow function like bellow
在 swift 3、4 或 5 中，您只需编写如下 didSelectRow 函数
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
self.view.endEditing(false)
yourPickerView.selectRow(0, inComponent: 0, animated: true)
yourPickerView.reloadAllComponents();
}
回答by Jeff John
In your button press action,
在你的按钮按下动作中，
[self.pickerView selectRow:0 inComponent:0 animated:YES];
回答by WrightsCS
Use multiple pickers, or use a switch block to determine which data should be loaded, and reload the picker.
使用多个选择器，或使用 switch 块来确定应该加载哪些数据，然后重新加载选择器。
回答by Sumit
Swift 3 & 4
斯威夫特 3 & 4
I had the same problem but no solution works,
我遇到了同样的问题，但没有解决方案，
then i use DispatchQueue it works
然后我使用 DispatchQueue 它工作
DispatchQueue.main.async(execute: {
self.picker.delegate = self
self.picker.dataSource = self
if self.pickerData.count > 0 {
self.pickerTextField.text = self.pickerData[0]
self.pickerTextField.isEnabled = true
} else {
self.pickerTextField.text = nil
self.pickerTextField.isEnabled = false
}
})
