Activity之间传递数据
数据的附加有两种方式:
- 一种是直接intent.putExtra();
- 另一种是先bundle.putXxx(),然后再调用Intent.putExtras(Bundle)添加bundle
- 其实两种的本质是一样的
从Activity返回数据
- startActivity新启动的Activity与原Activity相互独立,在关闭时不会返回任何信息。当需要返回数据时,可以使用startActivityForResult()方法启动一个Activity,新启动的Activity可以在关闭时给原Activity返回数据
- setResult()方法时专门用于向上一个活动返回数据
实例1
效果:
1 activity_main.xml
2 otheractivity.xml
3 tri_activity.xml
4 MainActivity.java
5 SecondActivity.java
6 TriActivity.java
1 activity_main.xml
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="数据传递1" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:text="数据传递2" />
2 otheractivity.xml
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="另一个Activity"
/>
3 tri_activity.xml
/
4 MainActivity.java
public class MainActivity extends Activity {
private Button btn1;
private Button btn2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn1=(Button) findViewById(R.id.button1);
btn2=(Button) findViewById(R.id.button2);
btn1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent=new Intent();
intent.setClass(MainActivity.this, SecondActivity.class);
intent.putExtra("myintro", "我是一个Android程序");
intent.putExtra("myNum", 50);
//putExtra("A",B)中,AB为键值对,第一个参数为键名,第二个参数为键对应的值。
//表示追加到Bundle中相应的值。
//如果想取出Intent对象中的这些值,需要在另一个Activity中用getXXXXXExtra方法,
//注意需要使用对应类型的方法,参数为键名
startActivity(intent);
}
});
btn2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Bundle bundle=new Bundle(); //利用Bundle类来传递数据
bundle.putString("bundle_s", "通过Bundle传递数据");
bundle.putInt("b_num", 30);
Intent intent=new Intent();
intent.setClass(MainActivity.this, TriActivity.class);
intent.putExtras(bundle);//直接将Bundle对象参数传递给intent
startActivity(intent);
}
});
}
}
5 SecondActivity.java
public class SecondActivity extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.otheractivity);
Intent intent=getIntent();
String str=intent.getStringExtra("myintro");
Integer integer=intent.getIntExtra("myNum",0);//defult是0 若没有传值则默认0
Toast.makeText(this, str, Toast.LENGTH_LONG).show();
Toast.makeText(this, integer+"", Toast.LENGTH_LONG).show();
}
}
6 TriActivity.java
public class TriActivity extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.tri_activity);
Bundle bundle=getIntent().getExtras();//获取从Intent中传过来的Bundle对象
String str=bundle.getString("bundle_s");
Integer integer=bundle.getInt("b_num");
Toast.makeText(this, str, Toast.LENGTH_LONG).show();
Toast.makeText(this, integer+"", Toast.LENGTH_LONG).show();
}
}
实例2
效果图:

1 activity_main.xml
2 activity_info.xml
3 MyCar.java
4 CarInfo.java
5 MainActivity.java
1 activity_main.xml
<TextView
android:id="@+id/tv1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/et1"
android:layout_alignParentLeft="true"
android:text="品牌" />
<EditText
android:id="@+id/et1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_toRightOf="@id/tv1"
/>
<TextView
android:id="@+id/tv2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/et2"
android:layout_toLeftOf="@+id/et1"
android:text="颜色" />
<EditText
android:id="@+id/et2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_toRightOf="@id/tv2"
android:layout_below="@id/et1"
/>
<Button
android:id="@+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/et2"
android:layout_centerHorizontal="true"
android:text="提交"
/>
2 activity_info.xml
<TextView
android:id="@+id/tv_info"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
3 MyCar.java
public class MyCar implements Serializable{//若要传递对象,需要实现Serializable接口
private String name;
private String color;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getColor() {
return color;
}
public void setColor(String color) {
this.color = color;
}
}
4 CarInfo.java
public class CarInfo extends Activity{
private MyCar car;
private TextView tv;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_info);
tv=(TextView) findViewById(R.id.tv_info);
Intent intent=getIntent();
car=(MyCar) intent.getSerializableExtra("car_data");//序列化
tv.setText(car.getName()+","+car.getColor());
}
}
5 MainActivity.java
public class MainActivity extends Activity {
private EditText etname,etcolor;
private Button btn;
private MyCar car;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
etname=(EditText) findViewById(R.id.et1);
etcolor=(EditText) findViewById(R.id.et2);
btn=(Button) findViewById(R.id.btn);
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
car=new MyCar();
car.setName(etname.getText().toString());
car.setColor(etcolor.getText().toString());
Intent intent=new Intent();
intent.setClass(MainActivity.this, CarInfo.class);
intent.putExtra("car_data", car);//传递对象 很重要
startActivity(intent);
}
});
}
}
实例3
效果:
1 activity_main.xml
2 activity02.xml
3 Activity02.java
4 MainActivity.java
1 activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<TextView
android:id="@+id/mText01"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/mText02"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<Button
android:id="@+id/mButton01"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="改变第一行文本的值"
/>
<Button
android:id="@+id/mButton02"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="改变第二行文本的值"
/>
</LinearLayout>
2 activity02.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="文本的值已经改变"
/>
</LinearLayout>
3 Activity02.java
public class Activity02 extends Activity{
//private int resultCode=100;//在有多个Activity返回时使用
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity02);
Intent mIntent = new Intent();
mIntent.putExtra("change01", "1000");
mIntent.putExtra("change02", "2000");
// 设置结果,并进行传送
setResult(RESULT_OK, mIntent);
finish();//finish()动作或者back动作后,会回调第一个页面的onActivityResult()方法
}
}
4 MainActivity.java
public class MainActivity extends Activity implements OnClickListener {
private TextView mText01;
private TextView mText02;
private Button button01;
private Button button02;
private Intent mIntent;
private int requestCode;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mText01 = (TextView) findViewById(R.id.mText01);
mText02 = (TextView) findViewById(R.id.mText02);
button01 = (Button) findViewById(R.id.mButton01);
button02 = (Button) findViewById(R.id.mButton02);
button01.setOnClickListener(this);
button02.setOnClickListener(this);
mText01.setText("01");
mText02.setText("02");
mIntent = new Intent();
mIntent.setClass(MainActivity.this, Activity02.class);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.mButton01:
// 请求码的值随便设置,但必须>=0,,用于在之后的回调中判断数据的来源
requestCode = 0;
startActivityForResult(mIntent, requestCode);
break;
case R.id.mButton02:
requestCode = 2;
startActivityForResult(mIntent, requestCode);
break;
default:
break;
}
}
// 回调方法,从第二个页面回来的时候会执行这个方法
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
String change01 = data.getStringExtra("change01");
String change02 = data.getStringExtra("change02");
// 根据上面发送过去的请求码来区别
switch (requestCode) {
case 0:
if(resultCode==RESULT_OK){//判断是哪个返回的
mText01.setText(change01);
break;}
case 2://因为只有一个 所以省略
mText02.setText(change02);
break;
default:
break;
}
}
}