Activity传值的几种方式

***Activity的传值

*第一种：Intent传值

主xml文件中设置按钮，点击跳转：

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/btn_name" 
    android:onClick="send"/> //设置点击跳转事件

主Java代码中传值：

public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
	}
	//点击按钮传递数据到指定activity中
	public void send(View view){
		Intent intent = new Intent(MainActivity.this, OtherActivity.class);
		intent.putExtra("name", "张三");//putExtra(String key,value):key表示唯一标示当前值的键，value为要传的数据
		intent.putExtra("age", 20);
		intent.putExtra("sex", '男');
		intent.putExtra("bl", true);
		startActivity(intent);
	}
}

目标活动的xml布局中添加textview来显示获取的值，目标活动的java代码中获取值：

protected void onCreate(Bundle savedInstanceState) {
	// TODO Auto-generated method stub
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_other);
	tv = (TextView) findViewById(R.id.tv);
	//1.获取激活组件的intent对象
	Intent intent = getIntent();
	//2.根据key获取传递的数据
	String name = intent.getStringExtra("name");
	int age = intent.getIntExtra("age", 0);//getIntExtra(表示获取数据的key,如果根据key没有获得数据时显示的默认值)
	char sex = intent.getCharExtra("sex", ' ');
	boolean bl = intent.getBooleanExtra("bl", false);
	//3.将数据显示到TextView中
	tv.setText("name:"+name+"age:"+age+"sex:"+sex+"bl:"+bl);	
}

*第二种：Bundle传值

public void send(View view){
	//1.创建Intent意图对象
	Intent intent = new Intent(MainActivity.this, OtherActivity.class);
	//2.创建bundle对象，用来存储需要传递的数据
	Bundle bundle = new Bundle();
	//3.将需要传递的数据存储到bundle对象中
	bundle.putString("name", "凤姐");
	bundle.putChar("sex", '女');
	bundle.putInt("age", 20);
	//4.将bundle对象存储到intent对象中
	intent.putExtras(bundle);
	//5.启动activity
	startActivity(intent);
}

protected void onCreate(Bundle savedInstanceState) {
	// TODO Auto-generated method stub
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_other);
	tv = (TextView) findViewById(R.id.tv);
	//1.获取激活组件的intent对象
	Intent intent = getIntent();
	//2.获取传递的bundle的对象
	Bundle bundle = intent.getExtras();
	//3.在bundle中根据key获取传递的数据
	String name = bundle.getString("name");
	int age = bundle.getInt("age");
	char sex = bundle.getChar("sex");
	//4.将数据显示到TextView中
	tv.setText("name:"+name+"age:"+age+"sex:"+sex);	
}

*第三种：使用Application全局对象传值

	1.单独创建一个类继承Application,将需要存储的数据定义，并提供set及get方法
	2.在发送的activity中存储数据
	3.在接收的activity中获取数据
	4.在清单文件中进行注册
		<application
		android:name="自定义application的包名.类名">
		</application>

public class MyApplication extends Application {
	private String name;
	private int age;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}	
}

public class MainActivity extends Activity {
	private MyApplication application;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
	}
	//点击按钮传递数据到目标activity中
	public void send(View view){
		application = (MyApplication) getApplication();
		application.setName("小明");
		application.setAge(18);
		startActivity(new Intent(MainActivity.this, OtherActivity.class));
	}
}

public class OtherActivity extends Activity {
	private TextView tv;
	private MyApplication application;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_other);
		tv = (TextView) findViewById(R.id.tv);

		application  = (MyApplication) getApplication();
		String name = application.getName();
		int age = application.getAge();
		tv.setText("name=" +name +"age="+age);
	}
}

<application
    android:name="com.example.creatactivity.MyApplication">
</application>

*第四种：启动Activity回传数据

案例演示：

public class MainActivity extends Activity {
	private EditText et_num1,et_num2;
	private TextView tv_result;
	private static final int REQUEST_CODE=1;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		et_num1 = (EditText) findViewById(R.id.editText1);
		et_num2 = (EditText) findViewById(R.id.editText2);
		tv_result = (TextView) findViewById(R.id.textView3);
	}
	//点击按钮传递数据到目标activity中
	public void onClick(View view){
		Intent intent = new Intent(MainActivity.this, OtherActivity.class);
		String num1 = et_num1.getText().toString();
		String num2 = et_num2.getText().toString();
		intent.putExtra("num1", num1);
		intent.putExtra("num2", num2);
		startActivityForResult(intent, REQUEST_CODE);//startActivityForResult(请求的intent对象，大于0的整数请求码)
	}
	 /*
	  * 该方法用来处理setResult()方法回传的数据
	  * int requestCode,请求码
	  * int resultCode,结果码
	  * Intent data，回传的intent意图对象
	  */
	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		// TODO Auto-generated method stub
		super.onActivityResult(requestCode, resultCode, data);
		if(requestCode == REQUEST_CODE&&resultCode==Activity.RESULT_OK){
			String result = data.getStringExtra("info");
			tv_result.setText(result);
		}
	}
}


public class OtherActivity extends Activity {
	private TextView tv_num1,tv_num2;
	private EditText et_result;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_other);
		tv_num1 = (TextView) findViewById(R.id.tv1);
		tv_num2 = (TextView) findViewById(R.id.tv3);
		et_result = (EditText) findViewById(R.id.et1);
		Intent intent = getIntent();
		tv_num1.setText(intent.getStringExtra("num1"));
		tv_num2.setText(intent.getStringExtra("num2"));
	}
	//点击按钮将数据回传到主activity
	public void send(View view){
		String result = et_result.getText().toString();//获取结果数据
		
		Intent intent = new Intent();
		intent.putExtra("info", result);
		
		setResult(Activity.RESULT_OK, intent);//setResult(表示请求的结果码，表示回传的数据的intent对象)
		OtherActivity.this.finish();//关闭当前的activity			
	}
}