Activity的显式跳转和隐式挑战

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.actitvtiydemo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="21" />
    <uses-permission android:name="android.permission.CALL_PHONE"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <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="com.example.actitvtiydemo.NextActivity" >
        </activity>
    </application>

</manifest>

<LinearLayout 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"
    android:orientation="vertical"
    
    tools:context="com.example.actitvtiydemo.MainActivity" >

  
    
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="通过显示意图跳转到下一个Activity"
        android:onClick="next"
         />
     <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="通过隐式意图跳转到打电话界面"
        android:onClick="call"
         />

</LinearLayout>

<?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="wrap_content"
        android:text="这是第二个ACtivity" />

</LinearLayout>

package com.example.actitvtiydemo;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;


public class MainActivity extends Activity {

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

    //显示意图，跳转到NextActivity.class
    public void next(View v){
        Intent intent = new Intent(this,NextActivity.class);
        startActivity(intent);
    }
    //隐式意图跳转到电话界面。一般通过设置Action和Data来处理
    /*
     * 隐式意图：就是要匹配Activity在清单文件中匹配了那些内容
     * 比如这打电话他配置了Action和Data，所以我们程序就会
     * 找到批评Action和Data的程序，从而实现跳转
     * 
     * */
    public void call(View v){
        Intent intent = new Intent();
        intent.setAction(Intent.ACTION_CALL);
        //注意这里要申请打电话权限
        intent.setData(Uri.parse("tel:10086"));
        startActivity(intent);
        
    }

}

package com.example.actitvtiydemo;

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

public class NextActivity extends Activity{
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.next_layout);
    }

}