回顾Intent

今天翻阅了以前写的一些代码，感觉还是有必要贴出来分享一下，这是一个以Intent为主体的分页代码，很简单。

就不做详细解释了，

首先要先新建一个SecondActivity.java和一个second.xml。然后在MainActivity中加入如下代码：

package com.example.intent;

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.Button;

import android.widget.Toast;

public class MainActivity extends Activity {

private Button mainBtn=null;

private final static int REQUEST_CODE=1;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mainBtn=(Button)findViewById(R.id.mainbtn);

mainBtn.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View arg0) {

Intent intent=new Intent();

intent.setClass(MainActivity.this, SecondActivity.class);

intent.putExtra("str", "Intent Demo");

startActivityForResult(intent, REQUEST_CODE);

}

});

}

@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

super.onActivityResult(requestCode, resultCode, data);

if(requestCode==REQUEST_CODE){

if(resultCode==SecondActivity.RESULT_CODE){

Bundle bundle=data.getExtras();

String string=bundle.getString("back");

Toast.makeText(MainActivity.this, string, Toast.LENGTH_LONG).show();

}

}

}

@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;

}

@Override

public boolean onOptionsItemSelected(MenuItem item) {

// Handle action bar item clicks here. The action bar will

// automatically handle clicks on the Home/Up button, so long

// as you specify a parent activity in AndroidManifest.xml.

int id = item.getItemId();

if (id == R.id.action_settings) {

return true;

}

return super.onOptionsItemSelected(item);

}

}

在SecondActivity加入如下代码：

package com.example.intent;

import android.R.integer;

import android.R.string;

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.TextView;

public class SecondActivity extends Activity {

private TextView secondTxt;

private Button button;

public final static int RESULT_CODE=1;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.second);

Intent intent=getIntent();

Bundle bundle=intent.getExtras();

String string=bundle.getString("str");

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

secondTxt.setText(string);

button=(Button)findViewById(R.id.button);

button.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View arg0) {

Intent intent=new Intent();

intent.putExtra("back", "back date");

setResult(RESULT_CODE, intent);

finish();

}

});

}

}

然后在main.xml加入以下代码：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context="com.example.intent.MainActivity" >

<TextView

android:id="@+id/textView"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="点击按钮"

/>

<Button

android:id="@+id/mainbtn"

android:layout_below="@id/textView"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="button"

/>

</RelativeLayout>

在second.xml加入以下代码：

<?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/secondTxt"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="点击按钮"

/>

<Button

android:id="@+id/button"

android:layout_below="@id/textView"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="Second"

/>

</LinearLayout>

重要的是在AndroidMainifest.xml加入一个Activity：

<activity

android:name=".SecondActivity"

android:label="@string/app_name" >

</activity>

否则的话，程序就运行不了，在以后的程序中，只要涉及多个页面，都要声明相应的类。