UIPickerView选择和隐藏

Question

如何使 UIPickerView 表现得像带有 webview 的那样，其中有一个下拉选择框，而不是像通常的网站那样下拉，iphone 将其变成包含所有选择的 UIPickerView。当您选择一个时，您的选择旁边会出现一个勾号，并更改下拉框的值。如何将“完成”按钮放在 UIPickerView 顶部以关闭 UIPickerView？

我已经知道 [pickerview setHidden:YES] 是用于隐藏 pickerview 的方法。我只是不知道如何在 UIPickerView 中包含“完成”按钮。

问候， 克里斯

Answer 1

这段代码将滑出一个选择器视图作为键盘，并在其顶部附加一个完成按钮。基本上，您想使用输入字段设置 inputAccessoryView。
您应该在输入字段的触地事件上调用此方法。

- (IBAction)showYourPicker:(id)sender {

// create a UIPicker view as a custom keyboard view
UIPickerView* pickerView = [[UIPickerView alloc] init];
[pickerView sizeToFit];
pickerView.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight);
pickerView.delegate = self;
pickerView.dataSource = self;
pickerView.showsSelectionIndicator = YES;
self.yourPickerView = pickerView;  //UIPickerView

yourTextField.inputView = pickerView;

// create a done view + done button, attach to it a doneClicked action, and place it in a toolbar as an accessory input view...
// Prepare done button
UIToolbar* keyboardDoneButtonView = [[UIToolbar alloc] init];
keyboardDoneButtonView.barStyle = UIBarStyleBlack;
keyboardDoneButtonView.translucent = YES;
keyboardDoneButtonView.tintColor = nil;
[keyboardDoneButtonView sizeToFit];

UIBarButtonItem* doneButton = [[[UIBarButtonItem alloc] initWithTitle:@"Done"
    style:UIBarButtonItemStyleBordered target:self
    action:@selector(pickerDoneClicked:)] autorelease];

[keyboardDoneButtonView setItems:[NSArray arrayWithObjects:doneButton, nil]];

// Plug the keyboardDoneButtonView into the text field...
yourTextField.inputAccessoryView = keyboardDoneButtonView;  

[pickerView release];
[keyboardDoneButtonView release];
}

最后，您的“完成”按钮调用“pickerDoneClicked”方法，您应该在其中添加
[yourTextField resignFirstResponder]; 这将隐藏选择器视图。

Answer 2

“完成”按钮放置在 UIToolBar 中。

使用 UIToolBar 的以下方法添加“完成”按钮。

- (void)setItems:(NSArray *)items animated:(BOOL)animated {

    UIToolbar*  mypickerToolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, 320, 56)];
    mypickerToolbar.barStyle = UIBarStyleBlackOpaque;
    [mypickerToolbar sizeToFit];

    NSMutableArray *barItems = [[NSMutableArray alloc] init];

    UIBarButtonItem *flexSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
    [barItems addObject:flexSpace];

    UIBarButtonItem *doneBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(DatePickerDoneClick)];
    [barItems addObject:doneBtn];

    [mypickerToolbar setItems:barItems animated:YES];

}