iOS编程之UIPickerView

初始化

_pickerView = [[UIPickerViewalloc]init];
_pickerView.center =self.view.center;
[self.viewaddSubview:_pickerView];

添加数据

  

 <UIPickerViewDataSource>

_pickerView.dataSource =self;

//返回pickerView要显示的组件的条目
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
     NSInteger result =0;
     if ([pickerViewisEqual:_pickerView]) {
         result = 1;//Figure-2.1
 //      result = 2;//Figure-2.2
     }
     return result;
}

//返回每个组件的数据条目
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
   NSInteger result =0;
   if ([pickerViewisEqual:_pickerView]) {
       result = 10;
   }
   return result;
}

  

添加代理

    <UIPickViewDelegate>

    _pickerView.delegate =self;

    //给每个组件的title赋值

    - (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component

    {

        NSString *title =nil;

        if ([pickerViewisEqual:_pickerView]) {

            title = [NSStringstringWithFormat:@"Row %ld",(long)row + 1];

        }

        return title;

    }

显示选中指示：

 _pickerView.showsSelectionIndicator = YES;

选择子项：

1.添加数据源

@interface ViewController (){

   NSArray *pickerDatas;

}

pickerDatas = [NSArrayarrayWithObjects:@"Row1",@"Row2",@"Row3",@"Row4",@"Row5",@"Row6",@"Row7",nil];

2.修改pickerview的返回条目

//返回每个组件的数据条目

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component

{

    NSInteger result =0;

    if ([pickerViewisEqual:_pickerView]) {

        result = [pickerDatascount];

    }

    return result;

}

3.修改pickerview的赋值

//给每个组件的title赋值

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component

{

    NSString *title =nil;

    if ([pickerViewisEqual:_pickerView]) {

        title = [NSStringstringWithFormat:@"%@",pickerDatas[row]];

    }

    return title;

}

4.添加选中pickerview子项方法

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component

{

    NSString *title =pickerDatas[row];

    UIAlertView *alert = [[UIAlertViewalloc]initWithTitle:@"Picker Selected"message:titledelegate:selfcancelButtonTitle:@"OK"otherButtonTitles:nil,nil];

    

    [alert show];

}