实验2 Activity和Intent-任务3：理解Task

一、运行效果图

 

二、核心代码

1.MainActivity中的代码：

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

public class MainActivity extends Activity
{
	private Button button1; 
	private Button button3;
	//private EditText mobileText;
	@Override
	protected void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		button1=(Button)findViewById(R.id.button1);
		button1.setOnClickListener(new OnClickListener()
		{
			public void onClick(View view){
				Intent intent=new Intent(MainActivity.this,SecondActivity.class);
				startActivity(intent);
			}
		});
		//mobileText=(EditText)this.findViewById(R.id)
		button3=(Button) findViewById(R.id.button3);
		button3.setOnClickListener(new OnClickListener()
		{
			//private String mobile;

			public void onClick(View view)
			{
				//String mobile=mobileText.getText().toString();
				Intent intent1= new Intent(Intent.ACTION_DIAL/*,Uri.parse("tel:"+1987)*/);
				intent1.setData(Uri.parse("tel:55565"));
				//intent1.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
				startActivity(intent1);
			}
		});
		
	}
}

2.SecondActivity中的代码：

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;

public class SecondActivity extends Activity
{

	private Button button2;

	@Override
	protected void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_second);
		
		button2=(Button) findViewById(R.id.button2);
		button2.setOnClickListener(new OnClickListener()
		{
			public void onClick(View view){
				Intent intent=new Intent(SecondActivity.this,MainActivity.class);
				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.second, menu);
		return true;
	}

}

3.activity_main中的代码：

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=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="91dp"
        android:text="@string/button1" />

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/button1"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="31dp"
        android:text="@string/button3" />

三、出现的问题

     1.在有的版本的模拟器中不能运行

     2.不能忘记在AndroidManifest中声明<uses-permission android:name="android.permission.CALL_PHONE"/>，

       获取打电话的声明