前言
NS_CLASS_AVAILABLE_IOS(2_0) __TVOS_PROHIBITED @interface UIPickerView : UIView <NSCoding, UITableViewDataSource>
@available(iOS 2.0, *) public class UIPickerView : UIView, NSCoding, UITableViewDataSource
- 选择框可以让用户以滑动的方式选择值。
1、UIPickerView 的创建
遵守协议 UIPickerViewDataSource, UIPickerViewDelegate
-
Objective-C
// 实例化 UIPickerView 对象
UIPickerView *pickerView = [[UIPickerView alloc] init]; // 设置代理
pickerView.dataSource = self;
pickerView.delegate = self; // 将 pickerView 添加到屏幕
[self.view addSubview:pickerView]; // 设置列数,必须设置,UIPickerViewDataSource 协议方法
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView { return 3;
} // 设置行数 ,必须设置,UIPickerViewDataSource 协议方法
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { return 10;
} // 设置各行内容,必须设置,UIPickerViewDelegate 方法
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component { return [NSString stringWithFormat:@"%li行 - %li列", row, component];
} -
Swift
// 实例化 UIPickerView 对象
let pickerView:UIPickerView = UIPickerView() // 设置代理
pickerView.dataSource = self
pickerView.delegate = self // 将 pickerView 添加到屏幕
self.view.addSubview(pickerView) // 设置列数,必须设置,UIPickerViewDataSource 协议方法
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int { return 3
} // 设置行数,必须设置,UIPickerViewDataSource 协议方法
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int { return 10
} // 设置各行内容,必须设置,UIPickerViewDelegate 方法
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? { return String(format: "%li行 - %li列", row, component)
}
2、UIPickerView 的设置
-
Objective-C
// 设置默认值
[pickerView selectRow:1 inComponent:0 animated:YES]; // 第 0 列的默认值为 1
[pickerView selectRow:2 inComponent:1 animated:YES]; // 第 1 列的默认值为 2
[pickerView selectRow:3 inComponent:2 animated:YES]; // 第 2 列的默认值为 3 // 设置 frame
/*
高度只有三个值:162, 180 和 216,默认为 216,设置为其它的值无效
*/
pickerView.frame = CGRectMake(10, 30, self.view.bounds.size.width - 20, 162); // 设置位置
pickerView.center = self.view.center; // 设置背景颜色
pickerView.backgroundColor = [UIColor orangeColor]; // 是否显示指示器
/*
default is NO
*/
pickerView.showsSelectionIndicator = YES; // 刷新指定的列
[pickerView reloadComponent:0]; // 刷新所有的列
[pickerView reloadAllComponents]; // 获取列数,只读
NSInteger numberOfComponents = pickerView.numberOfComponents; // 获取指定列的行数
NSInteger numberOfRows = [pickerView numberOfRowsInComponent:0]; // 获取指定行的尺寸
CGSize rowSize = [pickerView rowSizeForComponent:0]; // 获取指定列被选中的行数索引
NSInteger selectedIndex = [pickerView selectedRowInComponent:0]; // 获取指定行列的视图
UIView *view = [pickerView viewForRow:3 forComponent:0]; // 设置列宽
/*
不设置时为默认宽度,UIPickerViewDelegate 方法
*/
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component { return 50;
} // 设置行高
/*
不设置时为默认高度 32,UIPickerViewDelegate 方法
*/
- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component { return 50;
} -
Swift
// 设置默认值
pickerView.selectRow(1, inComponent: 0, animated: true) // 第 0 列的默认值为 1
pickerView.selectRow(2, inComponent: 1, animated: true) // 第 1 列的默认值为 2
pickerView.selectRow(3, inComponent: 2, animated: true) // 第 2 列的默认值为 3 // 设置 frame
/*
高度只有三个值:162, 180 和 216,默认为 216,设置为其它的值无效
*/
pickerView.frame = CGRectMake(10, 30, self.view.bounds.size.width - 20, 162) // 设置位置
pickerView.center = self.view.center // 设置背景颜色
pickerView.backgroundColor = UIColor.orangeColor() // 是否显示指示器
/*
default is NO
*/
pickerView.showsSelectionIndicator = true // 刷新指定的列
pickerView.reloadComponent(0) // 刷新所有的列
pickerView.reloadAllComponents() // 获取列数,只读
let numberOfComponents:Int = pickerView.numberOfComponents // 获取指定列的行数
let numberOfRows:Int = pickerView.numberOfRowsInComponent(0) // 获取指定行的尺寸
let rowSize:CGSize = pickerView.rowSizeForComponent(0) // 获取指定列被选中的行数索引
let selectedIndex:Int = pickerView.selectedRowInComponent(0) // 获取指定行列的视图
let view:UIView? = pickerView.viewForRow(3, forComponent: 0) // 设置列宽
/*
不设置时为默认宽度,UIPickerViewDelegate 方法
*/
func pickerView(pickerView: UIPickerView, widthForComponent component: Int) -> CGFloat { return 50
} // 设置行高
/*
不设置时为默认高度 32,UIPickerViewDelegate 方法
*/
func pickerView(pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat { return 50
}
3、UIPickerViewDataSource 协议方法
-
Objective-C
// 设置列数
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView { } // 设置行数
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { } -
Swift
// 设置列数
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int { } // 设置行数
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int { }
4、UIPickerViewDelegate 协议方法
-
Objective-C
// 设置各行内容为 字符串
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component { } // 设置各行内容为 NSAttributedString 型字符串
- (NSAttributedString *)pickerView:(UIPickerView *)pickerView attributedTitleForRow:(NSInteger)row forComponent:(NSInteger)component { } // 设置各行内容为 view
- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view { } // 设置列宽
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component { } // 设置行高
- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component { } // 检测行的选择状态,在滑动停止后触发
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { } -
Swift
// 设置各行内容为 字符串
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? { } // 设置各行内容为 NSAttributedString 型字符串
func pickerView(pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? { } // 设置各行内容为 view
func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView?) -> UIView { } // 设置列宽
func pickerView(pickerView: UIPickerView, widthForComponent component: Int) -> CGFloat { } // 设置行高
func pickerView(pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat { } // 检测行的选择状态,在滑动停止后触发
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) { }