在Activity之间传递数据

<1>传递基本数据类型
基本数据类型：
整：byte short int long
浮点：float double 
布尔：boolean
字符：char
引用：String

代码及运行结果

---------------------activity_main_xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" tools:context="com.example.g160628_11_widget.MainActivity">

<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="请输入用户名"
android:id="@+id/et_main_uname"/>

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="写心情"
android:onClick="xinq"/>

<!--文本框-->
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tv_main_showThink"/>

</LinearLayout>

------------------------------------MainActivity.java

package com.example.g160628_11_widget;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

private EditText et_main_uname;
private TextView tv_main_showThink;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

et_main_uname = (EditText) findViewById(R.id.et_main_uname);

tv_main_showThink = (TextView) findViewById(R.id.tv_main_showThink);

/*        String content=getIntent().getStringExtra("content");
tv_main_showThink.setText(content);*/

}

public void xinq(View view){
//点按钮拿到用户名
String uname=et_main_uname.getText().toString();
//邮递员
Intent intent=new Intent(this,ThinkActivity.class);
intent.putExtra("uname",uname);
//很普通的跳
//startActivity(intent);
//有目的的跳
startActivityForResult(intent,0x201);

}

//专门有一个方法来拿结果数据
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);

String content=data.getStringExtra("content");
tv_main_showThink.setText(content);
}
}

---------activity_think.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<TextView
android:layout_width="wrap_content"
android:layout_height="50dp"
android:id="@+id/tv_think_showName"
/>

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="上面是文本框,接收用户名的"/>

<EditText
android:layout_width="368dp"
android:layout_height="wrap_content"
android:lines="5"
android:hint="请输入心情"
android:gravity="top"
android:id="@+id/et_think_content"
/>

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="确定"
android:onClick="ok"/>

</LinearLayout>

------------------ThinkActivity.java

package com.example.g160628_11_widget;

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.TextView;

public class ThinkActivity extends AppCompatActivity {

private TextView tv_think_showName;
private EditText et_think_content;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_think);

tv_think_showName = (TextView) findViewById(R.id.tv_think_showName);
et_think_content = (EditText) findViewById(R.id.et_think_content);

//获取第一个页面传递过来的数据(获取邮递员的值)
String uname=getIntent().getStringExtra("uname");
tv_think_showName.setText("你好："+uname);
}

public void  ok(View view){
//拿心情的内容
String content=et_think_content.getText().toString();
Intent intent=new Intent(this,MainActivity.class);
intent.putExtra("content",content);

//设置结果
setResult(0x100,intent);
//干掉自己
finish();

//startActivity(intent);

}
}

效果：