先給大家展示下效果展示圖：
1 簡介
如果想在Activity中得到新打開Activity 關(guān)閉后返回的數(shù)據(jù)，需要使用系統(tǒng)提供的startActivityForResult(Intent intent, int requestCode)方法打開新的Activity，新的Activity 關(guān)閉后會(huì)向前面的Activity傳回?cái)?shù)據(jù)，為了得到傳回的數(shù)據(jù)，必須在前面的Activity中重寫onActivityResult(int requestCode, int resultCode, Intent data)方法。
public class MainActivity extends Activity {private final static String TAG="MainActivity";@Overridepublic 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) {//得到新打開Activity關(guān)閉后返回的數(shù)據(jù)//第二個(gè)參數(shù)為請(qǐng)求碼，可以根據(jù)業(yè)務(wù)需求自己編號(hào)startActivityForResult(new Intent(MainActivity.this, OtherActivity.class), 1);}});}/*** 為了得到傳回的數(shù)據(jù)，必須在前面的Activity中（指MainActivity類）重寫onActivityResult方法** requestCode 請(qǐng)求碼，即調(diào)用startActivityForResult()傳遞過去的值* resultCode 結(jié)果碼，結(jié)果碼用于標(biāo)識(shí)返回?cái)?shù)據(jù)來自哪個(gè)新Activity*/@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {String result = data.getExtras().getString("result");//得到新Activity 關(guān)閉后返回的數(shù)據(jù)Log.i(TAG, result);}}當(dāng)新Activity關(guān)閉后，新Activity返回的數(shù)據(jù)通過Intent進(jìn)行傳遞，android平臺(tái)會(huì)調(diào)用前面Activity 的onActivityResult()方法，把存放了返回?cái)?shù)據(jù)的Intent作為第三個(gè)輸入?yún)?shù)傳入，在onActivityResult()方法中使用第三個(gè)輸入?yún)?shù)可以取出新Activity返回的數(shù)據(jù)。
2 setResult
使用startActivityForResult(Intent intent, int requestCode)方法打開新的Activity，新Activity關(guān)閉前需要向前面的Activity返回?cái)?shù)據(jù)需要使用系統(tǒng)提供的setResult(int resultCode, Intent data)方法實(shí)現(xiàn)：
public class OtherActivity extends Activity {@Overrideprotected 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) {//數(shù)據(jù)是使用Intent返回Intent intent = new Intent();//把返回?cái)?shù)據(jù)存入Intentintent.putExtra("result", "My name is linjiqin");//設(shè)置返回?cái)?shù)據(jù)OtherActivity.this.setResult(RESULT_OK, intent);//關(guān)閉ActivityOtherActivity.this.finish();}});}}setResult()方法的第一個(gè)參數(shù)值可以根據(jù)業(yè)務(wù)需要自己定義，上面代碼中使用到的RESULT_OK是系統(tǒng)Activity類定義的一個(gè)常量，值為-1，代碼片斷如下：
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;}說明：當(dāng)點(diǎn)擊“打開新的Activity”按鈕，會(huì)跳轉(zhuǎn)到“我是新打開的Activity”頁面；
當(dāng)點(diǎn)擊“關(guān)閉”按鈕，關(guān)閉當(dāng)前頁面，同時(shí)跳轉(zhuǎn)到“我是舊的Activity”頁面，且會(huì)傳遞result參數(shù)給前一個(gè)Activity
3請(qǐng)求碼的作用
使用startActivityForResult(Intent intent, int requestCode)方法打開新的Activity，我們需要為startActivityForResult()方法傳入一個(gè)請(qǐng)求碼(第二個(gè)參數(shù))。請(qǐng)求碼的值是根據(jù)業(yè)務(wù)需要由自已設(shè)定，用于標(biāo)識(shí)請(qǐng)求來源。例如：一個(gè)Activity有兩個(gè)按鈕，點(diǎn)擊這兩個(gè)按鈕都會(huì)打開同一個(gè)Activity，不管是那個(gè)按鈕打開新Activity，當(dāng)這個(gè)新Activity關(guān)閉后，系統(tǒng)都會(huì)調(diào)用前面Activity的onActivityResult(int requestCode, int resultCode, Intent data)方法。在onActivityResult()方法如果需要知道新Activity是由那個(gè)按鈕打開的，并且要做出相應(yīng)的業(yè)務(wù)處理，這時(shí)可以這樣做：
@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://來自按鈕1的請(qǐng)求，作相應(yīng)業(yè)務(wù)處理case 2://來自按鈕2的請(qǐng)求，作相應(yīng)業(yè)務(wù)處理}}}4 結(jié)果碼的作用
在一個(gè)Activity中，可能會(huì)使用startActivityForResult()方法打開多個(gè)不同的Activity處理不同的業(yè)務(wù)，當(dāng)這些新Activity關(guān)閉后，系統(tǒng)都會(huì)調(diào)用前面Activity的onActivityResult(int requestCode, int resultCode, Intent data)方法。為了知道返回的數(shù)據(jù)來自于哪個(gè)新Activity，在onActivityResult()方法中可以這樣做(ResultActivity和NewActivity為要打開的新Activity)：
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 { // 在該Activity會(huì)打開ResultActivity和NewActivity@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {switch(resultCode){case 1:// ResultActivity的返回?cái)?shù)據(jù)case 2:// NewActivity的返回?cái)?shù)據(jù)}}}5 Demo源碼：
TestResultActivity.java
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;@Overrideprotected 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);}///跳轉(zhuǎn)到選擇品牌界面public void selectBrand(View view) {Intent intent = new Intent(this, TestResultActivity1.class);startActivityForResult(intent, 1);}///選擇要購買的電腦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請(qǐng)求返回的回調(diào)@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent intent) {switch (requestCode) { //resultCode為回傳的標(biāo)記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;}}}TestResultActivity1
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[]{"聯(lián)想", "戴爾"};@Overrideprotected 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);}///提交選擇的品牌結(jié)果public void submit(View view) {int index = listView.getCheckedItemPosition();if (index < 0) {Toast.makeText(this, "請(qǐng)選擇品牌", 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();}}TestResultActivity2
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;@Overrideprotected 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);}///提交選擇的電腦型號(hào)public void submit(View view){int index= listView.getCheckedItemPosition();if(index<0){Toast.makeText(this,"請(qǐng)選擇型號(hào)",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();}///初始化數(shù)據(jù)源public Map initData(){Map map=new HashMap();List<String> lists=new ArrayList<>();lists.add("聯(lián)想1G0001");lists.add("聯(lián)想1G0002");map.put("聯(lián)想1G",lists);lists=new ArrayList<>();lists.add("聯(lián)想2G0001");lists.add("聯(lián)想2G0002");map.put("聯(lián)想2G",lists);lists=new ArrayList<>();lists.add("戴爾1G0001");lists.add("戴爾1G0002");map.put("戴爾1G",lists);lists=new ArrayList<>();lists.add("戴爾2G0001");lists.add("戴爾2G0002");map.put("戴爾2G",lists);return map;}}以上所述是小編給大家介紹的Activity實(shí)例詳解之啟動(dòng)activity并返回結(jié)果，希望對(duì)大家有所幫助，如果大家有任何疑問請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)武林網(wǎng)網(wǎng)站的支持！
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