Android最简单的数据传递——用户注册

Activity间传递数据
1 基于消息的通信机制 Intent——–boudle , extra
用这种简单的形式，一般而言传递一些简单的类型是比较容易的，如int、string等
详细介绍下Intent机制
Intent包含两部分：
1 目的【action】——-要去到哪里去
2 内容【category、data】———-路上带些什么，区分性数据和内容性数据
简单数据传递：

String data = "HELLO"；Intent intent = new Intent(MainActivity.this, SecondActivity.class);intent.putExtra("extra_data", data);startActivity(intent);

putExtra()方法中第一个参数接收Key，第二个参数接收Value。
在SecondActivity中取出传过来的数据

Intent intent = getIntent();String data == intent.getStringExtra("extra_data");Log.i("SecondActivity","data");

写一个Demo.
1.新建工程，MainActivity.class

package com.example.passdata;import android.os.Bundle;import android.app.Activity;import android.content.Intent;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.RadioButton;public class MainActivity extends Activity {    private RadioButton raidoMale,radioFemale;    private EditText et_password,et_name;    private Button btn_send;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.acitivity_main);        et_name = (EditText) findViewById(R.id.et_name);        et_password = (EditText) findViewById(R.id.et_password);        raidoMale = (RadioButton) findViewById(R.id.radioMale);        radioFemale = (RadioButton) findViewById(R.id.radioFemale);        btn_send = (Button) findViewById(R.id.btn_send);        btn_send.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                // TODO Auto-generated method stub                passDate();            }        });    }    public void passDate(){        Intent intent = new Intent(this,SecondActivity.class);        //将数据存入Intent对象        intent.putExtra("name", et_name.getText().toString().trim());        intent.putExtra("password", et_password.getText().toString().trim());        String str = "";        if(raidoMale.isChecked()){            str = "男";        }else if (radioFemale.isChecked()){            str = "女";        }        intent.putExtra("sex", str);        startActivity(intent);    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.main, menu);        return true;    }}

activity_main.xml代码如下:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"     >    <LinearLayout        android:id="@+id/regist_password"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_below="@+id/regist_username"        android:layout_centerHorizontal="true"        android:layout_marginLeft="10dp"        android:layout_marginRight="10dp"        android:layout_marginTop="5dp"        android:orientation="horizontal" >        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:gravity="right"            android:paddingRight="5dp"            android:text="密码:"            android:width="80dp" />        <EditText             android:id="@+id/et_name"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:hint="请输入您的密码"            android:textSize="14dp"            android:inputType="textPassword"/>    </LinearLayout>    <LinearLayout          android:id="@+id/regist_username"        android:layout_height="wrap_content"        android:layout_width="match_parent"        android:layout_centerHorizontal="true"        android:layout_marginLeft="10dp"        android:layout_marginRight="10dp"        android:layout_marginTop="22dp"        android:orientation="horizontal"        >        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:gravity="right"            android:paddingRight="5dp"            android:text="用户名:"            android:width="80dp" />        <EditText             android:id="@+id/et_password"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:hint="请输入您的用户名"            android:textSize="14dp"/></LinearLayout>    <RadioGroup         android:id="@+id/radioGroup"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_below="@+id/regist_password"        android:layout_marginLeft="30dp"        android:contentDescription="性别"        android:orientation="horizontal"        android:layout_centerHorizontal="true">        <RadioButton             android:id="@+id/radioMale"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:checked="true"            android:text="男"/>          <RadioButton             android:id="@+id/radioFemale"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:checked="true"            android:text="女"/>    </RadioGroup>    <Button         android:id="@+id/btn_send"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_below="@+id/radioGroup"        android:layout_centerHorizontal="true"        android:layout_marginTop="24dp"        android:text="提交用户信息"/></RelativeLayout>

2.创建一个活动用来显示得到的数据
SecondActivity.class

package com.example.passdata;import android.os.Bundle;import android.app.Activity;import android.content.Intent;import android.view.Menu;import android.widget.TextClock;import android.widget.TextView;public class SecondActivity extends Activity {    private TextView tv_name,tv_password,tv_sex;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity02);        //获取Intent对象        Intent intent = getIntent();        //取出key对应的value值        String name = intent.getStringExtra("name");        String password = intent.getStringExtra("password");        String sex = intent.getStringExtra("sex");        tv_name = (TextView) findViewById(R.id.tv_name);        tv_password = (TextView) findViewById(R.id.tv_password);        tv_sex = (TextView) findViewById(R.id.tv_sex);        tv_name.setText("用户名:"+name);        tv_password.setText("密码:"+password);        tv_sex.setText("性别:"+sex);    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.activity02, menu);        return true;    }}

SecondActivity.class的界面activity02.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:id="@+id/tv_name"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:gravity="center"        android:layout_marginTop="10dp"        android:textSize="20dp"/>    <TextView         android:id="@+id/tv_password"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:gravity="center"        android:layout_marginTop="10dp"        android:textSize="20dp"/>    <TextView         android:id="@+id/tv_sex"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:gravity="center"        android:layout_marginTop="10dp"        android:textSize="20dp"/></LinearLayout>

3.在AndroidMainfest.xml 更改下活动标题栏

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.passdata"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="14"        android:targetSdkVersion="18" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.example.passdata.MainActivity"            android:label="填写用户信息" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <activity            android:name="com.example.passdata.SecondActivity"            android:label="展示用户信息" >        </activity>    </application></manifest>

4.