Android组件通信——Intent（二十三）

1. 认识Intent

1.1 知识点

（1）了解Intent的主要作用；

（2）掌握Activity程序对Intent操作的支持；

（3）可以使用Intent完成Activity程序间的跳转，也可以通过Intent接收返回数据

1.2 具体内容

以下用一个intent在Activity之间进行跳转的例子说明：

<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=".IntentActivity" >

    <Button
        android:id="@+id/but_first"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="跳转到第二个Activity"
         />

</RelativeLayout>

<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=".IntentActivity" >

    <TextView
        android:id="@+id/tv_second"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
       />

</RelativeLayout>

package com.example.intentproject;

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 IntentActivity extends Activity {
	Button but = null;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_intent_first);
		but = (Button) super.findViewById(R.id.but_first);
		but.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				Intent intent = new Intent(IntentActivity.this,SecondActivity.class);//创建Intent对象，并指定跳转的Activity
				intent.putExtra("msg", "你好，我是来自毛栗子的第一个Activity");
				startActivity(intent);
			}
		});
	}

}

package com.example.intentproject;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class SecondActivity extends Activity {
    TextView tv = null;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_intent_second);
		Intent intent = getIntent();//接收Intent对象
		String msg = intent.getStringExtra("msg");
		tv = (TextView) super.findViewById(R.id.tv_second);
		tv.setText(msg);//显示信息
	}


}

完成以上程序编写之后，不要忘记去主配文件当中去查看，新建的Activity是否已经注册。

<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=".IntentActivity" >

    <Button
        android:id="@+id/but_first"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="跳转到第二个Activity"
         />
    <TextView 
        android:id="@+id/tv_first"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/but_first"
        />

</RelativeLayout>

<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=".IntentActivity" >

    <TextView
        android:id="@+id/tv_second"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
       />
    <Button 
        android:id="@+id/but_second"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/tv_second"
        android:text="回传数据到第一个Activity"
        />

</RelativeLayout>

package com.example.intentproject;

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;
import android.widget.TextView;

public class IntentActivity extends Activity {
	Button but = null;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_intent_first);
		but = (Button) super.findViewById(R.id.but_first);
		but.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				Intent intent = new Intent(IntentActivity.this,SecondActivity.class);//创建Intent对象，并指定跳转的Activity
				intent.putExtra("msg", "你好，我是来自毛栗子的第一个Activity");
			    IntentActivity.this.startActivityForResult(intent, 1);//启动intent对象
			}
		});
	}
	
	@Override
	protected void onActivityResult(int requestCode,int resultCode,Intent data){
		switch(resultCode){
		    case RESULT_OK:
			     TextView tv = (TextView) super.findViewById(R.id.tv_first);
		         tv.setText(data.getStringExtra("returnmsg"));
		         break;
		    case RESULT_CANCELED:
		    	 break;
		    default:
		    	 break;
		}
	}

}

package com.example.intentproject;

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;
import android.widget.TextView;

public class SecondActivity extends Activity {
    TextView tv = null;
    Button but = null;
    Intent intent = null;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_intent_second);
		Intent intent = getIntent();//接收Intent对象
		String msg = intent.getStringExtra("msg");
		tv = (TextView) super.findViewById(R.id.tv_second);
		tv.setText(msg);//显示信息
		but = (Button) super.findViewById(R.id.but_second);
		but.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				Intent intent =  SecondActivity.this.getIntent();
				intent.putExtra("returnmsg", "你好，是卡哇伊吗？");
				setResult(RESULT_OK,intent);
				finish();
			}
		});
	}


}

1.3 课程小结

（1）Intent可以用于多个Activity间的跳转操作；

（2）使用Intent也可以接收Activity回传的数据。

2. Intent深入

2.1 知识点

（1）掌握内置Intent的调用操作。

2.2 具体内容

通过Intent跳转到网页：

package com.example.intentproject;

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

public class IntentActivity extends Activity {
	Button but = null;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_intent_first);
		but = (Button) super.findViewById(R.id.but_first);
		but.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				Uri uri = Uri.parse("http://www.baidu.com");
				Intent it =new Intent();
				it.setAction(Intent.ACTION_VIEW);//指定action
			    it.setData(uri);//设置数据
			    startActivity(it);
			}
		});
	}
	
	

}

以下使用Intent跳转到拨号页面：

package com.example.intentproject;

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

public class IntentActivity extends Activity {
	Button but = null;
	EditText edt = null;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_intent_first);
		but = (Button) super.findViewById(R.id.but_first);
		edt = (EditText) super.findViewById(R.id.edt);
		but.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				String num = edt.getText().toString().trim();
				Uri uri = Uri.parse("tel:"+num);
				Intent it =new Intent();
				it.setAction(Intent.ACTION_CALL);//指定action
			    it.setData(uri);//设置数据
			    startActivity(it);
			}
		});
	}
	
	

}

拨号还需要进行权限的配置：

<uses-permission 
        android:name="android.permission.CALL_PHONE"
        />

通过intent发送短信：

package com.example.intentproject;

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

public class IntentActivity extends Activity {
	Button but = null;
	EditText edt = null;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_intent_first);
		but = (Button) super.findViewById(R.id.but_first);
		edt = (EditText) super.findViewById(R.id.edt);
		but.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				String num = edt.getText().toString().trim();
				String note ="这是短信的内容";
				Uri uri = Uri.parse("smsto:"+num);
				Intent it =new Intent();
				it.setAction(Intent.ACTION_SENDTO);//指定action
				it.putExtra("sms_body", note);//指定附加信息
				it.setType("vndd.android-dir/mms-sms");//设置MIME类型，对方手机将以短信形式打开我们这发生的信息
			    it.setData(uri);//设置数据
			    startActivity(it);
			}
		});
	}
	
	

}