Activity实例详解之启动activity并返回结果

public class MainActivity extends Activity {
private final static String TAG="MainActivity";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button btnOpen=(Button)this.findViewById(R.id.btnOpen);
btnOpen.setOnClickListener(new View.OnClickListener(){
public void onClick(View v) {
//得到新打开Activity关闭后返回的数据
//第二个参数为请求码，可以根据业务需求自己编号
startActivityForResult(new Intent(MainActivity.this, OtherActivity.class), 1);
}
});
}
/**
* 为了得到传回的数据，必须在前面的Activity中（指MainActivity类）重写onActivityResult方法
*
* requestCode 请求码，即调用startActivityForResult()传递过去的值
* resultCode 结果码，结果码用于标识返回数据来自哪个新Activity
*/
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
String result = data.getExtras().getString("result");//得到新Activity 关闭后返回的数据
Log.i(TAG, result);
}
}

public class OtherActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.other);
Button btnClose=(Button)findViewById(R.id.btnClose);
btnClose.setOnClickListener(new View.OnClickListener(){
public void onClick(View v) {
//数据是使用Intent返回
Intent intent = new Intent();
//把返回数据存入Intent
intent.putExtra("result", "My name is linjiqin");
//设置返回数据
OtherActivity.this.setResult(RESULT_OK, intent);
//关闭Activity
OtherActivity.this.finish();
}
});
}
}

public class android.app.Activity extends ......{
public static final int RESULT_CANCELED = 0;
public static final int RESULT_OK = -1;
public static final int RESULT_FIRST_USER = 1;
}

@Override public void onCreate(Bundle savedInstanceState) {
....
button1.setOnClickListener(new View.OnClickListener(){
public void onClick(View v) {
startActivityForResult (new Intent(MainActivity.this, NewActivity.class), 1);
}
});
button2.setOnClickListener(new View.OnClickListener(){
public void onClick(View v) {
startActivityForResult (new Intent(MainActivity.this, NewActivity.class), 2);
}
});
@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch(requestCode){
case 1:
//来自按钮1的请求，作相应业务处理
case 2:
//来自按钮2的请求，作相应业务处理
}
}
}

public class ResultActivity extends Activity {
.....
ResultActivity.this.setResult(1, intent);
ResultActivity.this.finish();
}
public class NewActivity extends Activity {
......
NewActivity.this.setResult(2, intent);
NewActivity.this.finish();
}
public class MainActivity extends Activity { // 在该Activity会打开ResultActivity和NewActivity
@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch(resultCode){
case 1:
// ResultActivity的返回数据
case 2:
// NewActivity的返回数据
}
}
}

package mm.shandong.com.testresult;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
public class TestResultActivity extends AppCompatActivity {
EditText editTextBrand;
RadioGroup radioGroup;
TextView textViewXH;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test_result);
editTextBrand = (EditText) findViewById(R.id.editTextBrand);
radioGroup = (RadioGroup) findViewById(R.id.radioGroup);
textViewXH = (TextView) findViewById(R.id.textViewXH);
RadioButton radionButton = (RadioButton) radioGroup.getChildAt(0);
radionButton.setChecked(true);
}
///跳转到选择品牌界面
public void selectBrand(View view) {
Intent intent = new Intent(this, TestResultActivity1.class);
startActivityForResult(intent, 1);
}
///选择要购买的电脑
public void selectCompute(View view) {
Intent intent = new Intent(this, TestResultActivity2.class);
String brand = editTextBrand.getText().toString();
RadioButton radionButton =
(RadioButton) radioGroup.findViewById(radioGroup.getCheckedRadioButtonId());
String nc = radionButton.getText().toString();
intent.putExtra("brand", brand);
intent.putExtra("nc", nc);
startActivityForResult(intent, 2);
textViewXH.setText("");
}
///activity请求返回的回调
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
switch (requestCode) { //resultCode为回传的标记
case 1:
if (resultCode == 2) {
String brand = intent.getStringExtra("brand");
editTextBrand.setText(brand);
}
break;
case 2:
if (resultCode == 3) {
String xh = intent.getStringExtra("xh");
textViewXH.setText(xh);
}
break;
}
}
}

package mm.shandong.com.testresult;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class TestResultActivity1 extends AppCompatActivity {
ListView listView;
String[] brands = new String[]{"联想", "戴尔"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test_result1);
listView = (ListView) findViewById(R.id.listView);
ArrayAdapter arrayAdapter = new ArrayAdapter(this,
android.R.layout.simple_list_item_checked, brands);
listView.setAdapter(arrayAdapter);
listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
}
///提交选择的品牌结果
public void submit(View view) {
int index = listView.getCheckedItemPosition();
if (index < 0) {
Toast.makeText(this, "请选择品牌", Toast.LENGTH_SHORT).show();
return;
}
String brand = (String) listView.getItemAtPosition(index);
int resultCode = 2;
Intent intent = getIntent();
intent.putExtra("brand", brand);
setResult(2, intent);
finish();
}
}

package mm.shandong.com.testresult;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class TestResultActivity2 extends AppCompatActivity {
ListView listView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test_result2);
Intent intent=getIntent();
String brand=intent.getStringExtra("brand");
String nc=intent.getStringExtra("nc");
Map map=initData();
List<String> lists= (List<String>) map.get(brand+nc);
listView= (ListView) findViewById(R.id.listView);
ArrayAdapter arrayAdapter=new ArrayAdapter(this,
android.R.layout.simple_list_item_checked,lists);
listView.setAdapter(arrayAdapter);
listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
}
///提交选择的电脑型号
public void submit(View view){
int index= listView.getCheckedItemPosition();
if(index<0){
Toast.makeText(this,"请选择型号",Toast.LENGTH_SHORT).show();
return ;
}
String xh= (String) listView.getItemAtPosition(index);
int resultCode=2;
Intent intent=getIntent();
intent.putExtra("xh",xh);
setResult(3,intent);
finish();
}
///初始化数据源
public Map initData(){
Map map=new HashMap();
List<String> lists=new ArrayList<>();
lists.add("联想1G0001");
lists.add("联想1G0002");
map.put("联想1G",lists);
lists=new ArrayList<>();
lists.add("联想2G0001");
lists.add("联想2G0002");
map.put("联想2G",lists);
lists=new ArrayList<>();
lists.add("戴尔1G0001");
lists.add("戴尔1G0002");
map.put("戴尔1G",lists);
lists=new ArrayList<>();
lists.add("戴尔2G0001");
lists.add("戴尔2G0002");
map.put("戴尔2G",lists);
return map;
}
}