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Added in API level 1

ContentValues

public final class ContentValues
extends Object implements Parcelable

java.lang.Object
   ↳ android.content.ContentValues


该类用于存储 ContentResolver可以处理的一组值。

Summary

Constants

String TAG

Inherited constants

From interface android.os.Parcelable

Fields

public static final Creator<ContentValues> CREATOR

Public constructors

ContentValues()

使用默认初始大小创建一组空的值

ContentValues(int size)

使用给定的初始大小创建一组空值

ContentValues(ContentValues from)

创建从给定集合复制的一组值

Public methods

void clear()

删除所有值。

boolean containsKey(String key)

如果此对象具有指定的值,则返回true。

int describeContents()

描述此Parcelable实例的封送表示中包含的特殊对象的种类。

boolean equals(Object object)

指示其他某个对象是否“等于”这一个。

Object get(String key)

获取一个值。

Boolean getAsBoolean(String key)

获取一个值并将其转换为布尔值。

Byte getAsByte(String key)

获取一个值并将其转换为一个字节。

byte[] getAsByteArray(String key)

获取一个字节数组的值。

Double getAsDouble(String key)

获取一个值并将其转换为Double。

Float getAsFloat(String key)

获取一个值并将其转换为一个Float。

Integer getAsInteger(String key)

获取一个值并将其转换为一个Integer。

Long getAsLong(String key)

获取一个值并将其转换为Long。

Short getAsShort(String key)

获取一个值并将其转换为Short。

String getAsString(String key)

获取一个值并将其转换为一个String。

int hashCode()

返回对象的哈希码值。

Set<String> keySet()

返回一组所有的键

void put(String key, Short value)

为该集合添加一个值。

void put(String key, Long value)

为该集合添加一个值。

void put(String key, Double value)

为该集合添加一个值。

void put(String key, Integer value)

为该集合添加一个值。

void put(String key, String value)

为该集合添加一个值。

void put(String key, Boolean value)

为该集合添加一个值。

void put(String key, Float value)

为该集合添加一个值。

void put(String key, byte[] value)

为该集合添加一个值。

void put(String key, Byte value)

为该集合添加一个值。

void putAll(ContentValues other)

从传入的ContentValues中添加所有值。

void putNull(String key)

向该集合添加一个空值。

void remove(String key)

删除一个值。

int size()

返回值的数量。

String toString()

返回一个字符串,其中包含此对象的简明易懂的描述。

Set<Entry<StringObject>> valueSet()

返回一组所有的键和值

void writeToParcel(Parcel parcel, int flags)

将此对象平铺到一个包裹中。

Inherited methods

From class java.lang.Object
From interface android.os.Parcelable

Constants

TAG

Added in API level 1
String TAG

常量值:“ContentValues”

Fields

CREATOR

Added in API level 1
Creator<ContentValues> CREATOR

Public constructors

ContentValues

Added in API level 1
ContentValues ()

使用默认初始大小创建一组空的值

ContentValues

Added in API level 1
ContentValues (int size)

使用给定的初始大小创建一组空值

Parameters
size int: the initial size of the set of values

ContentValues

Added in API level 1
ContentValues (ContentValues from)

创建从给定集合复制的一组值

Parameters
from ContentValues: the values to copy

Public methods

clear

Added in API level 1
void clear ()

删除所有值。

containsKey

Added in API level 1
boolean containsKey (String key)

如果此对象具有指定的值,则返回true。

Parameters
key String: the value to check for
Returns
boolean true if the value is present, false otherwise

describeContents

Added in API level 1
int describeContents ()

描述此Parcelable实例的封送表示中包含的特殊对象的种类。 例如,如果对象将在writeToParcel(Parcel, int)的输出中包含writeToParcel(Parcel, int) ,则此方法的返回值必须包含CONTENTS_FILE_DESCRIPTOR位。

Returns
int a bitmask indicating the set of special object types marshaled by this Parcelable object instance.

equals

Added in API level 1
boolean equals (Object object)

指示其他某个对象是否“等于”这一个。

equals方法在非空对象引用上实现等价关系:

  • It is reflexive: for any non-null reference value x, x.equals(x) should return true.
  • It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
  • It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
  • It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
  • For any non-null reference value x, x.equals(null) should return false.

Objectequals方法实现了对象上最可能的等价关系; 也就是说,对于任何非空参考值xy ,当且仅当xy指向同一对象( x == y的值为true )时,此方法返回true

请注意,无论何时重写此方法,通常都必须重写 hashCode方法,以便维护 hashCode方法的一般合同,该方法声明等同对象必须具有相同的哈希代码。

Parameters
object Object: the reference object with which to compare.
Returns
boolean true if this object is the same as the obj argument; false otherwise.

get

Added in API level 1
Object get (String key)

获取一个值。 有效的值类型StringBooleanNumber ,并byte[]实现。

Parameters
key String: the value to get
Returns
Object the data for the value, or null if the value is missing or if null was previously added with the given key

getAsBoolean

Added in API level 1
Boolean getAsBoolean (String key)

获取一个值并将其转换为布尔值。

Parameters
key String: the value to get
Returns
Boolean the Boolean value, or null if the value is missing or cannot be converted

getAsByte

Added in API level 1
Byte getAsByte (String key)

获取一个值并将其转换为一个字节。

Parameters
key String: the value to get
Returns
Byte the Byte value, or null if the value is missing or cannot be converted

getAsByteArray

Added in API level 1
byte[] getAsByteArray (String key)

获取一个字节数组的值。 请注意,此方法不会将任何其他类型转换为字节数组。

Parameters
key String: the value to get
Returns
byte[] the byte[] value, or null is the value is missing or not a byte[]

getAsDouble

Added in API level 1
Double getAsDouble (String key)

获取一个值并将其转换为Double。

Parameters
key String: the value to get
Returns
Double the Double value, or null if the value is missing or cannot be converted

getAsFloat

Added in API level 1
Float getAsFloat (String key)

获取一个值并将其转换为一个Float。

Parameters
key String: the value to get
Returns
Float the Float value, or null if the value is missing or cannot be converted

getAsInteger

Added in API level 1
Integer getAsInteger (String key)

获取一个值并将其转换为一个Integer。

Parameters
key String: the value to get
Returns
Integer the Integer value, or null if the value is missing or cannot be converted

getAsLong

Added in API level 1
Long getAsLong (String key)

获取一个值并将其转换为Long。

Parameters
key String: the value to get
Returns
Long the Long value, or null if the value is missing or cannot be converted

getAsShort

Added in API level 1
Short getAsShort (String key)

获取一个值并将其转换为Short。

Parameters
key String: the value to get
Returns
Short the Short value, or null if the value is missing or cannot be converted

getAsString

Added in API level 1
String getAsString (String key)

获取一个值并将其转换为一个String。

Parameters
key String: the value to get
Returns
String the String for the value

hashCode

Added in API level 1
int hashCode ()

返回对象的哈希码值。 这种方法支持散列表的好处,例如HashMap提供的HashMap

hashCode的总合同是:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
  • If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
  • It is not required that if two objects are unequal according to the equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

尽可能合理实用,由类Object定义的hashCode方法确实为不同的对象返回不同的整数。 (这通常通过将对象的内部地址转换为整数来实现,但Java TM编程语言不需要此实现技术。)

Returns
int a hash code value for this object.

keySet

Added in API level 11
Set<String> keySet ()

返回一组所有的键

Returns
Set<String> a set of all of the keys

put

Added in API level 1
void put (String key, 
                Short value)

为该集合添加一个值。

Parameters
key String: the name of the value to put
value Short: the data for the value to put

put

Added in API level 1
void put (String key, 
                Long value)

为该集合添加一个值。

Parameters
key String: the name of the value to put
value Long: the data for the value to put

put

Added in API level 1
void put (String key, 
                Double value)

为该集合添加一个值。

Parameters
key String: the name of the value to put
value Double: the data for the value to put

put

Added in API level 1
void put (String key, 
                Integer value)

为该集合添加一个值。

Parameters
key String: the name of the value to put
value Integer: the data for the value to put

put

Added in API level 1
void put (String key, 
                String value)

为该集合添加一个值。

Parameters
key String: the name of the value to put
value String: the data for the value to put

put

Added in API level 1
void put (String key, 
                Boolean value)

为该集合添加一个值。

Parameters
key String: the name of the value to put
value Boolean: the data for the value to put

put

Added in API level 1
void put (String key, 
                Float value)

为该集合添加一个值。

Parameters
key String: the name of the value to put
value Float: the data for the value to put

put

Added in API level 1
void put (String key, 
                byte[] value)

为该集合添加一个值。

Parameters
key String: the name of the value to put
value byte: the data for the value to put

put

Added in API level 1
void put (String key, 
                Byte value)

为该集合添加一个值。

Parameters
key String: the name of the value to put
value Byte: the data for the value to put

putAll

Added in API level 1
void putAll (ContentValues other)

从传入的ContentValues中添加所有值。

Parameters
other ContentValues: the ContentValues from which to copy

putNull

Added in API level 1
void putNull (String key)

向该集合添加一个空值。

Parameters
key String: the name of the value to make null

remove

Added in API level 1
void remove (String key)

删除一个值。

Parameters
key String: the name of the value to remove

size

Added in API level 1
int size ()

返回值的数量。

Returns
int the number of values

toString

Added in API level 1
String toString ()

返回一个字符串,其中包含此对象的简明易懂的描述。

Returns
String a printable representation of this object.

valueSet

Added in API level 1
Set<Entry<StringObject>> valueSet ()

返回一组所有的键和值

Returns
Set<Entry<StringObject>> a set of all of the keys and values

writeToParcel

Added in API level 1
void writeToParcel (Parcel parcel, 
                int flags)

将此对象平铺到一个包裹中。

Parameters
parcel Parcel: The Parcel in which the object should be written.
flags int: Additional flags about how the object should be written. May be 0 or PARCELABLE_WRITE_RETURN_VALUE.

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