Intent 直接法、间接法实现界面的跳转

一、Intent的组成部分：
action 动作
data  数据
category 分类
type  类型
component 组件
Extra  扩展信息

二、Intent 寻找目标组件的方法：
1，通过组件名直接指定
2，通过intent-filter过滤指定

Demo:

package com.amaker.intent;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
	public static final String MY_ACITON = "com.amaker.intent.my_action";
    private Button btn;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				start();
			}
		});
    }
    //直接法
    /*void start(){
    	Intent intent = new Intent(this,MainActivity2.class);
    	
    	startActivity(intent);
    }*/
    //间接法跳转
    void start(){
    	
    	Intent intent = new Intent(MY_ACITON);
    	startActivity(intent);
    }
}

package com.amaker.intent;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity2 extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main2);
    }
}

注意配置文件中第二个Activity下面的intent-filter里面的内容:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.amaker.intent"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="8" />

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".MainActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        
        <activity android:name="MainActivity2">
        	<intent-filter>
        		<action android:name="com.amaker.intent.my_action"/>
        		<category android:name="android.intent.category.DEFAULT" />
        	</intent-filter>
        </activity>

    </application>
</manifest>