一.两个页面的xml文件
factivity
<Button android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="直接跳转" />
<Button android:id="@+id/button2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="跳转至改变textview" />
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="回传的数据显示" />
sactivity
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="返回FA" />
二.在manifest中注册Activity,为首先启动的activity提供标注
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".Factivity"
android:label="@string/app_name" >
<intent-filter>//首先启动的activity的标注
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity>
android:name=".Sactivity"
android:label="@string/app_name" >
</activity>
</application>
三.第一个种跳转:无返回结果的跳转
Factivity文件编写
private Button bt1;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.factivity);
bt1 = (Button) findViewById(R.id.button1);
bt1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Intent intent = new Intent(Factivity.this, Sactivity.class);
startActivity(intent);
}
此时在模拟器中测试,点击“直接跳转”可以转致另一个页面
四.第二个种跳转:含有返回结果的跳转
Factivity文件编写
private Button bt2;
private TextView tv;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.factivity);
bt2 = (Button) findViewById(R.id.button2);
tv= (TextView) findViewById(R.id.textView1);
bt2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(Factivity.this, Sactivity.class);
startActivityForResult(intent, 1);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if(requestCode==1&&resultCode==2){
String content = data.getStringExtra("data");
tv.setText(content);
}
}
Sactivity文件编写
private Button bt;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.sactivity);
bt= (Button) findViewById(R.id.button);
bt.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent data= new Intent();
data.putExtra("data","hello");
setResult(2,data);
finish();
}
});
}
此时点击“跳转至改变textview”可跳转至另一页面,点击另一页面的按钮返回原页面,可见textview已经被修改为“hello”
五.代码的具体理解
Intent intent = new Intent(Factivity.this, Sactivity.class);
startActivity(intent);
可以认为intent是startActivity的一个指引,表达从什么地方(Factivity.this)到什么地方(Sactivity.class)
Intent intent = new Intent(Factivity.this, Sactivity.class);
startActivityForResult(intent, 1);
startActivityForResult中的intent同理,“1”代表了从Factivity到Sactivity的申请代号
Intent data= new Intent();
data.putExtra("data","hello");
setResult(2,data);
finish();
intent不再代表跳转,而是作为信使携带返回参数的代号“data”和具体参数“hello”
setResult()方法中的2是从Sactivity到Factivity的结果代号
if(requestCode==1&&resultCode==2){
String content = data.getStringExtra("data");
tv.setText(content);}
在验证申请代号和结果代号之后,初始化一个String通过intent的getStringExtra方法用返回参数的代号“data”得到返回的具体参数