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Added in API level 1

Point

public class Point
extends Object implements Parcelable

java.lang.Object
   ↳ android.graphics.Point


点保存两个整数坐标

Summary

Inherited constants

From interface android.os.Parcelable

Fields

public static final Creator<Point> CREATOR

public int x

public int y

Public constructors

Point()
Point(int x, int y)
Point(Point src)

Public methods

int describeContents()

Parcelable接口方法

final boolean equals(int x, int y)

如果点的坐标等于(x,y),则返回true

boolean equals(Object o)

指示其他某个对象是否“等于”这一个。

int hashCode()

返回对象的哈希码值。

final void negate()

否定点的坐标

final void offset(int dx, int dy)

用dx,dy偏移点的坐标

void readFromParcel(Parcel in)

根据存储在指定宗地中的数据设置点的坐标。

void set(int x, int y)

设置点的x和y坐标

String toString()

返回对象的字符串表示形式。

void writeToParcel(Parcel out, int flags)

将此点写入指定的宗地。

Inherited methods

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

Fields

CREATOR

Added in API level 13
Creator<Point> CREATOR

x

Added in API level 1
int x

y

Added in API level 1
int y

Public constructors

Point

Added in API level 1
Point ()

Point

Added in API level 1
Point (int x, 
                int y)

Parameters
x int
y int

Point

Added in API level 1
Point (Point src)

Parameters
src Point

Public methods

describeContents

Added in API level 13
int describeContents ()

Parcelable接口方法

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 (int x, 
                int y)

如果点的坐标等于(x,y),则返回true

Parameters
x int
y int
Returns
boolean

equals

Added in API level 1
boolean equals (Object o)

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.

对于类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引用同一对象( 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,该方法声明相等对象必须具有相同的哈希代码。

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

hashCode

Added in API level 1
int hashCode ()

返回对象的哈希码值。 为了散列表的好处而支持该方法,例如由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.

negate

Added in API level 1
void negate ()

否定点的坐标

offset

Added in API level 1
void offset (int dx, 
                int dy)

用dx,dy偏移点的坐标

Parameters
dx int
dy int

readFromParcel

Added in API level 13
void readFromParcel (Parcel in)

根据存储在指定宗地中的数据设置点的坐标。 要将点写入宗地,请调用writeToParcel()。

Parameters
in Parcel: The parcel to read the point's coordinates from

set

Added in API level 1
void set (int x, 
                int y)

设置点的x和y坐标

Parameters
x int
y int

toString

Added in API level 1
String toString ()

返回对象的字符串表示形式。 通常, toString方法返回一个字符串,用于“文本地表示”该对象。 结果应该是一个简洁但内容丰富的表述,对于一个人来说很容易阅读。 建议所有子类重写此方法。

ObjecttoString方法返回一个字符串,其中包含对象为实例的类的名称,符号字符“ @ ”以及对象的哈希代码的无符号十六进制表示形式。 换句话说,这个方法返回一个字符串,其值等于:

 getClass().getName() + '@' + Integer.toHexString(hashCode())
 

Returns
String a string representation of the object.

writeToParcel

Added in API level 13
void writeToParcel (Parcel out, 
                int flags)

将此点写入指定的宗地。 要从宗地恢复点,请使用readFromParcel()

Parameters
out Parcel: The parcel to write the point's coordinates into
flags int: Additional flags about how the object should be written. May be 0 or PARCELABLE_WRITE_RETURN_VALUE.

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