【移动应用开发技术】Android中如何实现Activity之间的数据传递

【移动应用开发技术】Android中如何实现Activity之间的数据传递

1、通过Intent传递1.1、基本数据类型传递/upload/information/20200623/125/118488.jpgIntent

intent

=

new

Intent(this,

Activity2.class);

intent.putExtra(String

name,

boolean

value);

intent.putExtra(String

name,

byte

value);

intent.putExtra(String

name,

char

value);

intent.putExtra(String

name,

short

value);

intent.putExtra(String

name,

int

value);

intent.putExtra(String

name,

float

value);

intent.putExtra(String

name,

long

value);

intent.putExtra(String

name,

double

value);

startActivity(intent);Intent

intent

=

getIntent();

boolean

bool

=

intent.getBooleanExtra(String

name,

boolean

defaultValue);

byte

bt

=

intent.getByteExtra(String

name,

byte

defaultValue);

char

ch

=

intent.getCharExtra(String

name,

char

defaultValue);

short

sh

=

intent.getShortExtra(String

name,

short

defaultValue);

int

i

=

intent.getIntExtra(String

name,

int

defaultValue);

float

fl

=

intent.getFloatExtra(String

name,

float

defaultValue);

long

lg

=

intent.getLongExtra(String

name,

long

defaultValue);

double

db

=

intent.getDoubleExtra(String

name,

double

defaultValue);1.2、复杂数据类型传递intent.putExtra(String

name,

String

value);

intent.putExtra(String

name,

int[]

value);

intent.putExtra(String

name,

Parcelable

value);

intent.putExtra(String

name,

Serializable

value);

intent.putExtra(String

name,

CharSequence

value);

intent.putStringArrayListExtra(String

name,

ArrayList<String>

value);1.3、自定义数据类型传递public

class

Student{

public

String

name;

public

int

age;

}1.3.1、实现Serializable接口public

final

class

String

implements

java.io.Serializable,

Comparable<String>,

CharSequence

public

class

ArrayList<E>

extends

AbstractList<E>

implements

List<E>,

RandomAccess,

Cloneable,

java.io.Serializable

public

class

HashMap<K,V>

extends

AbstractMap<K,V>

implements

Map<K,V>,

Cloneable,

Serializablepublic

class

Student

implements

Serializable{

private

static

final

long

serialVersionUID

=

1L;

public

String

name;

public

int

age;

}intent.putExtra(String

name,

Serializable

value);

intent.getSerializableExtra(String

name);1.3.2、实现Parcelable接口public

class

Student

implements

Parcelable{

public

String

name;

public

int

age;

protected

Student(Parcel

in)

{

name

=

in.readString();

age

=

in.readInt();

}

public

static

final

Creator<Student>

CREATOR

=

new

Creator<Student>()

{

@Override

public

Student

createFromParcel(Parcel

in)

{

return

new

Student(in);

}

@Override

public

Student[]

newArray(int

size)

{

return

new

Student[size];

}

};

@Override

public

int

describeContents()

{

return

0;

}

@Override

public

void

writeToParcel(Parcel

dest,

int

flags)

{

dest.writeString(name);

dest.writeInt(age);

}

}intent.putExtra(String

name,

Parcelable

value);

intent.getParcelableExtra(String

name);2、通过全局变量传递public

class

Transmitter

{

public

static

Student

student;

}//传递

Student

stu

=

new

Student();

Transmitter.student

=

stu;

Intent

intent

=

new

Intent(this,

Activity2);

startActivity(intent);

//接收

onCreate(...){

Student

stu

=

Transmitter.student;

}3、通过SharedPreferences传递SharedPreferences

sp

=

getSharedPreferences("FILENAME",

MODE_PRIVATE);

SharedPreferences.Editor

editor

=

sp.edit();

editor.putBoolean(String

key,

boolean

value);

editor.putFloat(String

key,

float

value);

editor.putInt(String

key,

int

value);

editor.putLong(String

key,

long

value);

editor.putString(String

key,

String

value);

editor.putStringSet(String

key,

Set<String>

values);

//mit();

editor.apply();

startActivity(...);SharedPreferences

sp

=

getSharedPreferences("FILENAME",

MODE_PRIVATE);

sp.getBoolean(String

key,

boolean

defValue);

sp.getFloat(String

key,

float

defValue);

sp.getInt(String

key,

int

defValue);

sp.getLong(String

key,

long

defValue);

sp.getString(String

key,

String

defValue);

sp.getStringSet(String

key,

Set<String>

defValue);关于SharedPreferences有几点需要注意：public

class

HashSet<E>

extends

AbstractSet<E>

implements

Set<E>,

Cloneable,

java.io.Serializable

public

class

TreeSet<E>

extends

AbstractSet<E>

implements

NavigableSet<E>,

Cloneable,

java.io.Serializable

public

class

LinkedHashSet<E>

extends

HashSet<E>

implements

Set<E>,

Cloneable,

java.io.Serializable

{4、通过SystemProperties传递/**

*

Gives

access

to

the

system

properties

store.

The

system

properties

*

store

contains

a

list

of

string

key-value

pairs.

*

*

{@hide}

*/

public

class

SystemPropertiesSystemProperties.set("NAME",

"Shawn.XiaFei");

startActivity(...);SystemProperties.get("NAME");

//或者

SystemProperties.get("NAME",

"defValue");/**

*

Set

the

value

for

the

given

key.

*

@throws

IllegalArgumentException

if

the

key

exceeds

32

characters

*

@throws

IllegalArgumentException

if

the

value

exceeds

92

characters

*/

public

static

void

set(String

key,

String

val)

{

if

(key.length()

>

PROP_NAME_MAX)

{

throw

new

IllegalArgumentException("key.length

>

"

+

PROP_NAME_MAX);

}

if

(val

!=

null

&&

val.length()

>

PROP_VALUE_MAX)

{

throw

new

IllegalArgumentException("val.length

>

"

+

PROP_VALUE_MAX);

}

native_set(key,

val);

}Unable

to

set

property

"NAME"

to

"Shawn.XiaFei":

connection

failed;

errno=13

(Permission

denied)

type=1400

audit(0.0:167):

avc:

denied

{

write

}

for

name="property_service"

dev="tmpfs"

ino=10696

scontext=u:r:untrusted_app_25:s0:c512,c768

tcontext=u:object_r:property_socket:s0

tclass=sock_file

permissive=05、通过SettingsProvider传递/*Settings.System.putInt(ContentResolver

cr,

String

name,

int

value);

Settings.System.putString(ContentResolver

cr,

String

name,

String

value);

Settings.System.putFloat(ContentResolv