BaseItemProvider

java.lang.Object
- ohos.agp.components.BaseItemProvider

直接已知子类:

RecycleItemProvider
```
public abstract class BaseItemProvider
extends Object
```
Provides a BaseItemProvider object to associate an ComponentProvider item with the fundamental data of the component.
A provider provides access to data items and creates a Component for each item in the dataset. When the content in a dataset changes, the subscriber is notified to respond to the changes, and the updated content is refreshed on the screen synchronously.

从以下版本开始:

3

构造器概要

构造器
构造器说明

BaseItemProvider()
The constructor

构造器
构造器	说明
`BaseItemProvider()`	The constructor

方法概要

所有方法实例方法抽象方法具体方法
限定符和类型	方法	说明
`void`	`addDataSubscriber(DataSetSubscriber subscriber)`	Adds a dataset subscriber.
`abstract Component`	`getComponent(int position, Component convertComponent, ComponentContainer parent)`	Obtains a component that displays data in a specified position in the data set.
`int`	`getComponentTypeCount()`	Obtains the number of component types of all items in a dataset.
`abstract int`	`getCount()`	Obtains the total number of data items in a provider.
`TextFilter`	`getFilter()`	Obtains the text filter.
`abstract Object`	`getItem(int position)`	Obtains the data item in a specified position in the data set.
`int`	`getItemComponentType(int position)`	Obtains the component type of a data item in a dataset based on the position.
`abstract long`	`getItemId(int position)`	Obtains the row ID of a data item in a specified position in the data set.
`void`	`notifyDataChanged()`	Refreshes the component of an updated data item.
`void`	`notifyDataInvalidated()`	Called when a provider data is invalid.
`void`	`notifyDataSetItemChanged(int position)`	Refreshes the component of an updated data item.
`void`	`notifyDataSetItemInserted(int position)`	Refreshes the component for which a specified data item has changed.
`void`	`notifyDataSetItemRangeChanged(int startPos, int countItems)`	Refreshes the component for which a specified number of data items starting from the given position have changed.
`void`	`notifyDataSetItemRangeInserted(int startPos, int countItems)`	Refreshes the component for which a specified number of data items starting from the given position have been inserted.
`void`	`notifyDataSetItemRangeRemoved(int startPos, int countItems)`	Refreshes the component from which a specified number of data items starting from the given position have been removed.
`void`	`notifyDataSetItemRemoved(int position)`	Refreshes the component from which a specified data item has been removed.
`void`	`onItemMoved(int from, int to)`	Called internally when a component item should be moved to other position into dataset.
`void`	`removeDataSubscriber(DataSetSubscriber subscriber)`	Removes a dataset subscriber.
`void`	`setFilter(TextFilter filter)`	Sets the text filter.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - BaseItemProvider
```
public BaseItemProvider()
```
    The constructor
    
    从以下版本开始:
    
    3
- 方法详细资料
  - getCount
```
public abstract int getCount()
```
    Obtains the total number of data items in a provider.
    
    返回:
    
    Returns the total number of data items in the provider.
  - getItem
```
public abstract Object getItem(int position)
```
    Obtains the data item in a specified position in the data set.
    
    参数:
    
    position - Indicates the position of the data item in the data set.
    
    返回:
    
    Returns the data item in the specified position.
  - getItemId
```
public abstract long getItemId(int position)
```
    Obtains the row ID of a data item in a specified position in the data set.
    
    参数:
    
    position - Indicates the position of the row ID of the data item.
    
    返回:
    
    Returns the row ID of the data item in the specified position.
  - getComponent
```
public abstract Component getComponent(int position,
                                       Component convertComponent,
                                       ComponentContainer parent)
```
    Obtains a component that displays data in a specified position in the data set.
    
    参数:
    
    position - Indicates the position of the component in the data set.
    
    convertComponent - Indicates the previous component to be reused. This parameter can be null if there is no such component.
    
    parent - Indicates the parent component matching the component to be obtained.
    
    返回:
    
    Returns the component matching the data item in the specified position.
  - getItemComponentType
```
public int getItemComponentType(int position)
```
    Obtains the component type of a data item in a dataset based on the position.
    Each time a component layout is added to the dataset, a component type must be added to match the component layout. The component type value ranges from 0 to the result of getComponentTypeCount() minus 1. For example, a component layout containing one key matches the component type value 0, and a component layout containing two keys matches the component type value 1.
    
    参数:
    
    position - Indicates the position of the component item in the provider dataset.
    
    返回:
    
    Returns the component type.
  - getComponentTypeCount
```
public int getComponentTypeCount()
```
    Obtains the number of component types of all items in a dataset. By default, the number of component types is 1.
    
    返回:
    
    Returns the number of component types of all items in the dataset.
  - notifyDataChanged
```
public void notifyDataChanged()
```
    Refreshes the component of an updated data item.
    Each registered subscriber is notified using the DataSetPublisher#notifyChanged() method.
    
    从以下版本开始:
    
    4
  - notifyDataInvalidated
```
public void notifyDataInvalidated()
```
    Called when a provider data is invalid.
    Each registered subscriber is notified using the DataSetPublisher#informInvalidated() method.
    
    从以下版本开始:
    
    4
  - notifyDataSetItemChanged
```
public void notifyDataSetItemChanged(int position)
```
    Refreshes the component of an updated data item.
    Each registered subscriber is notified using the DataSetPublisher#notifyItemChanged(int) method.
    
    参数:
    
    position - Indicates the position of the item in the data set.
    
    从以下版本开始:
    
    4
  - notifyDataSetItemInserted
```
public void notifyDataSetItemInserted(int position)
```
    Refreshes the component for which a specified data item has changed.
    To notify data change subscribers, call DataSetPublisher#notifyItemChanged(int).
    
    参数:
    
    position - Indicates the position of the changed data item in the data set.
    
    从以下版本开始:
    
    4
  - notifyDataSetItemRemoved
```
public void notifyDataSetItemRemoved(int position)
```
    Refreshes the component from which a specified data item has been removed.
    To notify data change subscribers, call DataSetPublisher#notifyItemRemoved(int).
    
    参数:
    
    position - Indicates the position of the removed data item in the data set.
    
    从以下版本开始:
    
    4
  - notifyDataSetItemRangeChanged
```
public void notifyDataSetItemRangeChanged(int startPos,
                                          int countItems)
```
    Refreshes the component for which a specified number of data items starting from the given position have changed.
    To notify data change subscribers, call DataSetPublisher#notifyItemRangeChanged(int, int).
    
    参数:
    
    startPos - Indicates the position of the first data item that has changed.
    
    countItems - Indicates the number of data items that have changed.
    
    从以下版本开始:
    
    4
  - notifyDataSetItemRangeInserted
```
public void notifyDataSetItemRangeInserted(int startPos,
                                           int countItems)
```
    Refreshes the component for which a specified number of data items starting from the given position have been inserted.
    To notify data change subscribers, call DataSetPublisher#notifyItemRangeInserted(int, int).
    
    参数:
    
    startPos - Indicates the position of the first data item that has been inserted.
    
    countItems - Indicates the number of data items that have been inserted.
    
    从以下版本开始:
    
    4
  - notifyDataSetItemRangeRemoved
```
public void notifyDataSetItemRangeRemoved(int startPos,
                                          int countItems)
```
    Refreshes the component from which a specified number of data items starting from the given position have been removed.
    To notify data change subscribers, call DataSetPublisher#notifyItemRangeRemoved(int, int).
    
    参数:
    
    startPos - Indicates the position of the first data item that has been removed.
    
    countItems - Indicates the number of data items that have been removed.
    
    从以下版本开始:
    
    4
  - addDataSubscriber
```
public final void addDataSubscriber(DataSetSubscriber subscriber)
```
    Adds a dataset subscriber.
    
    参数:
    
    subscriber - Indicates the subscriber to notify when the content in the dataset changes.
    
    从以下版本开始:
    
    4
  - removeDataSubscriber
```
public final void removeDataSubscriber(DataSetSubscriber subscriber)
```
    Removes a dataset subscriber.
    
    参数:
    
    subscriber - Indicates the subscriber to notify when the content in the dataset changes.
    
    从以下版本开始:
    
    4
  - setFilter
```
public void setFilter(TextFilter filter)
```
    Sets the text filter.
    
    参数:
    
    filter - Indicates the text filter.
    
    另请参阅:
    
    TextFilter
  - getFilter
```
public TextFilter getFilter()
```
    Obtains the text filter.
    
    返回:
    
    Returns the text filter.
    
    另请参阅:
    
    TextFilter
  - onItemMoved
```
public void onItemMoved(int from,
                        int to)
```
    Called internally when a component item should be moved to other position into dataset.
    
    参数:
    
    from - Indicates the original position of the Component item in the dataset.
    
    to - Indicates the destination position of the Component item in the dataset.

类 BaseItemProvider

构造器概要

方法概要

从类继承的方法 java.lang.Object

构造器详细资料

BaseItemProvider

方法详细资料

getCount

getItem

getItemId

getComponent

getItemComponentType

getComponentTypeCount

notifyDataChanged

notifyDataInvalidated

notifyDataSetItemChanged

notifyDataSetItemInserted

notifyDataSetItemRemoved

notifyDataSetItemRangeChanged

notifyDataSetItemRangeInserted

notifyDataSetItemRangeRemoved

addDataSubscriber

removeDataSubscriber

setFilter

getFilter

onItemMoved