兩個Activity之間通過Intent相互(雙向)傳遞資料
阿新 • • 發佈:2019-02-12
兩個Activity通過Intent相互交換資料,在Activity中用一個Button 選擇是否接受資料,不能直接寫在onCreate中否則在Activity1 中獲取從Activity2傳送的資料時會崩潰,原因是因為在Activity中會通過Intent再建立一個Activity1的介面 而Activity1在記憶體中是存在的。
package com.example.he.text2; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; /** * Created by he on 2016/3/19. */ public class FirstActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.firstlayout); Button first_button =(Button)findViewById(R.id.first_button); Button second_button=(Button)findViewById(R.id.second_button); //向SecondActivity傳資料的按鈕 first_button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent =new Intent(FirstActivity.this,SecondActivity.class); intent.putExtra("first_action","hello secondActivity"); startActivity(intent); } }); //從SecondActivity得到資料的按鈕 second_button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent =new Intent(FirstActivity.this,SecondActivity.class); startActivityForResult(intent,1); } }); } //讀取返回資訊 @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { switch (requestCode){ case 1: if (resultCode==RESULT_OK){ String s=data.getStringExtra("data_return"); Toast.makeText(FirstActivity.this, s, Toast.LENGTH_SHORT).show(); // Log.i("FirstActivity",s); } break; } } }
package com.example.he.text2; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; /** * Created by he on 2016/3/19. */ public class SecondActivity extends Activity { @Overrideprotected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.secondlayout); Button button1 = (Button) findViewById(R.id.button1); Button button2 = (Button) findViewById(R.id.button2); button1.setOnClickListener(new View.OnClickListener() { @Overridepublic void onClick(View v) { Intent intent2 = new Intent(); intent2.putExtra("data_return", "hello firstActivity"); setResult(RESULT_OK, intent2); finish(); } }); button2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent1 = getIntent(); String data = intent1.getStringExtra("first_action"); Toast.makeText(SecondActivity.this, data, Toast.LENGTH_SHORT).show(); // Log.i("SecondActivity", data); } }); } @Override public void onBackPressed() { Intent intent2 = new Intent(); intent2.putExtra("data_return", "hello firstActivity"); setResult(RESULT_OK, intent2); finish(); } }