Android最简单的数据传递——用户注册

短命女 2022-06-14 04:39 256阅读 0赞

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:

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.![这里写图片描述][SouthEast]  
![这里写图片描述][SouthEast 1]

[SouthEast]: /images/20220614/342261c610cc44248e6a8eab8a8f2a7a.png
[SouthEast 1]: /images/20220614/f932b6ba0f9f433ca0adac6ac1004185.png