重溫 Activity Intent 如何向下傳遞數(shù)據(jù) 向上傳遞數(shù)據(jù)

1、使用Intent向下傳遞數(shù)據(jù)

Intent?intent?=?new?Intent(MainActivity.this,SecongActivity.class);
intent.putExtra("data_from_MainActivity","I?am?MainActivity");
startActivity(intent);

從SecondActivity取數(shù)據(jù)

Intent?intent?=?getIntent();
String?data?=?intent.getStringExtra("data_from_MainActivity");

根據(jù)傳遞的數(shù)據(jù)的類型選擇getIntExtra()/getBooleanExtra...

2、向上傳遞數(shù)據(jù)

MainActivity.java

Intent?intent1?=?new?Intent("sunny.example.comeonintent.ACTION");
startActivityForResult(intent1,1);

期望返回數(shù)據(jù)

startActivityForResult()

void android.support.v4.app.FragmentActivity.startActivityForResult(Intent intent, int requestCode)

SubActivity.java

Intent?intent?=?new?Intent();
intent.putExtra("data_from_sub",?"I?am?Sub");
setResult(RESULT_OK,intent);//RESULT_OK?-1;RESULT_CANCELED?0;

在MainActivity中接收數(shù)據(jù)

@Override
	protected?void?onActivityResult(int?RequestCode,int?ResultCode,Intent?data){
		TextView?tv1?=?(TextView)findViewById(R.id.tv1);
		TextView?tv2?=?(TextView)findViewById(R.id.tv2);
		switch(RequestCode){
		case?1:
			if(ResultCode?==?RESULT_OK){
				String?returnData1?=?data.getStringExtra("data_from_sub");
				tv1.setText(returnData1);
			}else{}
		case?2:
			if(ResultCode?==?RESULT_OK){
				String?returnData2?=?data.getStringExtra("data_from_third");
				tv2.setText(returnData2);
			}else{
				
				}
		default:
		}
		
	}