Starting Activities and Getting Results
如果，要想达到这个效果，你需要调用startActivityForResult(Intent, int) （这个method的第二个参数描定义了这个回调）。当返回的时候，这个activity将要调用onActivityResult(int, int, Intent) 。
如果这个activity存在，它能够调用setResult(int) 返回数据给 调用它的父activity。它必须的有一个返回码，这个返回码可以是ESULT_CANCELED, RESULT_OK, or any custom values starting at RESULT_FIRST_USER。
如果,调用的child activity失败,这个parent activity 将会收到的返回码是RESULT_CANCELED.
public class MyActivity extends Activity {
...
static final int PICK_CONTACT_REQUEST = 0;
protected boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
// When the user center presses, let them pick a contact.
startActivityForResult(
new Intent(Intent.ACTION_PICK,
new Uri("content://contacts")),
PICK_CONTACT_REQUEST);
return true;
}
return false;
}
protected void onActivityResult(int requestCode, int resultCode,
Intent data) {
if (requestCode == PICK_CONTACT_REQUEST) {
if (resultCode == RESULT_OK) {
// A contact was picked. Here we will just display it
// to the user.
startActivity(new Intent(Intent.ACTION_VIEW, data));
}
}
}
}
一个转载的Demo
activity1
package com.android.ActivityGo;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.widget.TextView;
public class Activity1 extends Activity {
EditText first,second;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main1);
first = (EditText) findViewById(R.id.first);
second = (EditText) findViewById(R.id.second);
findViewById(R.id.start).setOnClickListener(new OnClickListener(){
public void onClick(View v) {
// TODO Auto-generated method stub
sendCalculate();
}
});
}
public void sendCalculate(){
Intent i = new Intent(this, Activity2.class);
Bundle b = new Bundle();
b.putString("first", first.getText().toString());
b.putString("second", second.getText().toString());
i.putExtras(b);
startActivityForResult(i,10);
}
@Override
protected void onActivityResult(int requestCode, int resultCode,
Intent data){
// 10 -1
System.out.println(requestCode+">>>>"+resultCode);
setTitle(requestCode+">>>>"+resultCode);
switch (resultCode){
case RESULT_OK:
// Bundle b = data.getExtras();
// String string = b.getString("CALCULATION");
updateText("55555555555555");
}
}
public void updateText(String s){
TextView t = (TextView) findViewById(R.id.text);
t.setText(s);
}
}
activity2
package com.android.ActivityGo;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
public class Activity2 extends Activity {
String value;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main2);
Intent i = this.getIntent();
Bundle b = i.getExtras();
String v1 = b.getString("first");
String v2 = b.getString("second");
value = v1 + v2;
findViewById(R.id.reply).setOnClickListener(new OnClickListener(){
public void onClick(View v) {
// TODO Auto-generated method stub
replyCalculation();
}
});
}
public void replyCalculation(){
Intent i = new Intent();
Bundle b = new Bundle();
b.putString("CALCULATION", value);
i.putExtras(b);
this.setResult(RESULT_OK);
this.finish();
}
}
一个小Demo
主界面：
public class StartResultTestActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button=(Button) findViewById(R.id.button1);
Button button2=(Button) findViewById(R.id.button2);
// Intent intent=new Intent(this, cls)
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
startActivityForResult(new Intent(StartResultTestActivity.this, Activity1.class), 1);
}
});
button2.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
startActivityForResult(new Intent(StartResultTestActivity.this, Activity2.class), 2);
}
});
}
}
二级页面
public class Activity1 extends Activity{
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity1);
// findViewById(R)
Button button=(Button) findViewById(R.id.button11);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
// Intent intent=new Intent(Activity1.this, StartResultTestActivity.class) ;
Intent intent=new Intent();
setResult(1, intent);
finish();//如果不加这句话 这个页面将不会发生跳转到主界面 这句话的本质是：结束当前的 把它从activity的栈顶中移除
}
});
}
}