实验三 Task 打电话界面跳转
一、实验目的
理解Task的含义
二、实验内容
该应用的activity1有三个按钮,一个按钮跳转到Activity2,一个按钮跳转到直接拨打电话的页面,最后一个跳转到拨号界面,打电话这个功能不属于本应用,我们假设它为应用一。
首先默认进入本应用的activity1,点击button1后跳转到activity2,再点击activity2的按钮后跳转到activity1,再点击button2跳转到直接拨打电话页面,点击返回,再点击button3跳转到拨号界面,最后依次点返回按钮,大家看Task栈效果。
三、实验结果图
最后依次返回的顺序是我们所打开的界面的反顺序,可见Task栈的先进后出、后进先出的特点。
四、实验代码
FirstActivity:
package com.test3.task;
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 FirstActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_first);
}
public void toSecond(View view){
Intent intent = new Intent (this,SecondActivity.class);
startActivity(intent);
}
public void toCall(View view){
Intent intentPhone = new Intent(Intent.ACTION_DIAL);
intentPhone.setData(Uri.parse("tel:10086"));
startActivity(intentPhone);
}
public void toDial(View view){
Intent intentDail= new Intent(Intent.ACTION_DIAL);
intentDail.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intentDail);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.first, 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);
}
}
SecondActivity:
package com.test3.task;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
public class SecondActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
}
public void toFirst(View view){
Intent intent = new Intent (this,FirstActivity.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;
}
@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);
}
}
activity_first.xml:
<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.test3.task.FirstActivity" >
<Button
android:id="@+id/btntoSecond"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="118dp"
android:onClick="toSecond"
android:text="@string/to_Second" />
<Button
android:id="@+id/btntoCall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:onClick="toCall"
android:text="@string/to_call" />
<Button
android:id="@+id/btntoDial"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/btntoCall"
android:layout_centerHorizontal="true"
android:layout_marginTop="32dp"
android:onClick="toDial"
android:text="@string/to_dial" />
</RelativeLayout>
activity_second.xml:
<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.test3.task.SecondActivity" >
<Button
android:id="@+id/btntoFirst"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:onClick="toFirst"
android:text="@string/to_First" />
</RelativeLayout>
五、存在的问题
跳转至拨号界面有很多种方法,我试了好几种,可是只有我写出的这种在我的模拟器上可以正确运行。我参考的大神说的那些方法不知道问题出在哪,还需要进一步研究。
实验四 Activity的生命周期
一、实验目的
(1)观察Activity生命周期经历的主要方法
(2)如果使用LogCat观察输出,掌握如何设置LogFilter
(3)观察何时调用onPause方法?
(4)观察何时调用onStop方法?
二、实验内容
编写两种不同的Activity(NormalActivity、DialogActivity),通过跳转至不同的Activity来观察MainActivity的生命周期,注意个方法调用的时间。
三、实验结果图
以下是过程:打开应用->点击Start NormalActivity->返回->点击Start DialogActivity->返回->退出应用,输出的info,可见,在两次点击按钮和第二次返回时调用了onPause()函数,在打开NormalActivity和结束应用是调用了onStop()函数。充分展示了Activity生命周期的两个分支。
三、实验代码
MainActivity:
package com.test4.lifecycle;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
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);
Log.i("MainActivity","onCreat");
}
public void toNormal(View view){
Intent intentNormal = new Intent (this, NormalActivity.class);
startActivity(intentNormal);
}
public void toDialog(View view){
Intent intentDialog = new Intent (this, DialogActivity.class);
startActivity(intentDialog);
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
Log.i("MainActivity","onDestroy");
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
Log.i("MainActivity","onPause");
}
@Override
protected void onRestart() {
// TODO Auto-generated method stub
super.onRestart();
Log.i("MainActivity","onRestart");
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
Log.i("MainActivity","onResume");
}
@Override
protected void onStart() {
// TODO Auto-generated method stub
super.onStart();
Log.i("MainActivity","onStart");
}
@Override
protected void onStop() {
// TODO Auto-generated method stub
super.onStop();
Log.i("MainActivity","onStop");
}
@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);
}
}
NormalActivity和 DialogActivity并没有进行改动。
activity_main:
<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.test4.lifecycle.MainActivity" >
<Button
android:id="@+id/toNormal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="136dp"
android:onClick="toNormal"
android:text="@string/toNormal" />
<Button
android:id="@+id/toDialog"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/toNormal"
android:layout_centerHorizontal="true"
android:layout_marginTop="27dp"
android:onClick="toDialog"
android:text="@string/toDialog" />
</RelativeLayout>
activity_normal:
<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.test4.lifecycle.NormalActivity" >
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/Normal_output"
android:textAppearance="?android:attr/textAppearanceMedium" />
</RelativeLayout>
activity_dialog:
<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.test4.lifecycle.DialogActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/Dialog_output"
android:textAppearance="?android:attr/textAppearanceMedium" />
</RelativeLayout>
AndroidManifest.xml(清单文件中的一部分):
<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=".NormalActivity"
android:label="@string/title_activity_normal" >
</activity>
<activity
android:name=".DialogActivity"
android:theme="@android:style/Theme.Dialog"
android:label="@string/title_activity_dialog" >
</activity>
</application>
五、存在的问题
虽然知道了Activity的生命周期的两个分支,但是除了这个例子外,不知道还有什么其他的触发另一种分支的条件,对于Activity的生命周期的了解不是很深入透彻,需要继续花时间。
PS:本篇的具体知识点会在自学笔记中讲解