1.Activity的建立，配置和使用

来源：互联网发布：淘宝发票抬头哪里设置编辑：程序博客网时间：2024/06/05 03:01

一、Activity 功能：1.从一个界面跳转到另一个界面，传送Activity所携带的数据，或接收Activity的数据

二、用法 1、掌握其如何跳转到下一个Activity ，此处，单指 Intent 最普通的跳转下一个Activity界面方法

三、注意点：代码注释

主界面源代码：

package com.example.preferenceactivityapi;

import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.app.Activity;
import android.app.ExpandableListActivity;
import android.app.LauncherActivity;
import android.content.Intent;
import android.view.Menu;
import android.widget.ArrayAdapter;

public class MainActivity extends LauncherActivity { //继承 LuncherActivity ，必须覆写 Intent intentForPosition（int position·）方法
String[] names={
"查看设置参数", //设置ListAdapter呈现的列表名称,设置主界面显示的数字
"查看星际兵种"
};
Class<?>[] clazzs={ //由于每个选项单机后都是Activity页面，需要Intent作为转接跳板，此处定义两个activity类
PreferenceActivityTest.class, //PreferenceActivity子类，显示设置选项参数并进行保存的窗口
ExpandableListActivityTest.class //是ExpandableListActivity的子类,可扩展的列表窗口
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ArrayAdapter<String> adapter=new ArrayAdapter<String>(MainActivity.this,android.R.layout.simple_list_item_1,names);
setListAdapter(adapter); //简单设置ListAcitivity的设置 // ArrayAdapter的应用，将需要显示的文字显示出来，无需 Layout界面
}

@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 Intent intentForPosition(int position){

/ /定义LancherActivity,单击后呈现的Intent，必须覆盖此方法
return new Intent(MainActivity.this,clazzs[position]); // 当用户点击文字后，跳转其指向的Activity界面
}
}

跳转ExpandableListActivityTest.class 界面代码，此处代码解析略：

package com.example.preferenceactivityapi;

import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListAdapter;
import android.widget.Gallery.LayoutParams;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

public class ExpandableListActivityTest extends ExpandableListActivity{
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
ExpandableListAdapter adapter=new BaseExpandableListAdapter(){

int[] logos=new int[]{
R.drawable.yecun1,
R.drawable.yecun2,
R.drawable.yecun3
};
private String[] armTypes=new String[]{
"神族兵种","虫族兵种","人族兵种"
};
private String[][] arms=new String[][]{
{"狂战士","龙骑士","黑暗圣堂","电兵"},
{"小狗","刺蛇","飞龙","自爆飞机"},
{"机枪兵","护士MM","幽灵"}
};
@Override
public Object getChild(int arg0, int arg1) {
// TODO Auto-generated method stub
return arms[arg0][arg1];
}

@Override
public long getChildId(int arg0, int arg1) {
// TODO Auto-generated method stub
return arg1;
}
private TextView getTextView(){
@SuppressWarnings("deprecation")
AbsListView.LayoutParams lp=new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,64);
TextView textView=new TextView(ExpandableListActivityTest.this);
textView.setLayoutParams(lp);
textView.setGravity(Gravity.CENTER_VERTICAL|Gravity.LEFT);
textView.setPadding(36, 0, 0, 0);
textView.setTextSize(20);
return textView;
}
@Override
public View getChildView(int arg0, int arg1, boolean arg2,
View arg3, ViewGroup arg4) {
// TODO Auto-generated method stub
TextView textView=getTextView();
textView.setText(getChild(arg0,arg1).toString());
return textView;
}

@Override
public int getChildrenCount(int arg0) {
// TODO Auto-generated method stub
return arms[arg0].length;
}

@Override
public Object getGroup(int arg0) {
// TODO Auto-generated method stub
return armTypes[arg0];
}

@Override
public int getGroupCount() {
// TODO Auto-generated method stub
return armTypes.length;
}

@Override
public long getGroupId(int arg0) {
// TODO Auto-generated method stub
return arg0;
}

@Override
public View getGroupView(int groupPosition, boolean arg1, View arg2,
ViewGroup arg3) {
// TODO Auto-generated method stub
LinearLayout L1=new LinearLayout(ExpandableListActivityTest.this);
L1.setOrientation(0);
ImageView logo=new ImageView(ExpandableListActivityTest.this);
logo.setImageResource(logos[groupPosition]);
L1.addView(logo);
TextView textView=getTextView();
textView.setText(getGroup(groupPosition).toString());
L1.addView(textView);
return L1;
}

@Override
public boolean hasStableIds() {
// TODO Auto-generated method stub
return true;
}

@Override
public boolean isChildSelectable(int arg0, int arg1) {
// TODO Auto-generated method stub
return true;
}
};
setListAdapter(adapter);
}
}

配置 Activity ，如果界面跳转另一个界面时，记得一定要配置Activity ，之后的Intent 一样，Manifest 内的 Application内配置Activity，Intent属性都在Activity内配置，

代码如下：

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

<uses-sdk
android:minSdkVersion="15"
android:targetSdkVersion="18" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.preferenceactivityapi.MainActivity" //主界面Activity
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="ExpandableListActivityTest" // 跳转ExpandableListActivity界面的Activity ，内部可以定义Intent 等各种属性，见 Intent 详解
android:label="查看星际兵种"
></activity>
<activity android:name="PreferenceActivityTest" // 跳转参数设置Activity
android:label="设置程序参数"
></activity>
</application>

</manifest>

PreferenceActivityTest界面布局代码：此代码可添加后续章节的Fragment 注意点：

<?xml version="1.0" encoding="utf-8"?> //设置 Preference界面布局
<preference-headers
xmlns:android="http://schemas.android.com/apk/res/android">
<header android:fragment="com.example.preferenceactivityapi.PreferenceActivityTest$Prefs1Fragment" //Preference与Fragment复合使用，fragment为包名+ fragment类名，下方为fragment 定义
android:icon="@drawable/yecun1"
android:title="程序设置"
android:summary="设置应用的相关选项"/>
<header android:fragment="com.example.preferenceactivityapi.PreferenceActivityTest$Prefs2Fragment" //一致
android:icon="@drawable/yecun2"
android:title="界面选项设置"
android:summary="设置显示界面的相关选项">
<extra android:name="website"
android:value="www.crazyit.org"/>
</header>
<header
android:icon="@drawable/yecun3"
android:title="百度"
android:summary="使用Intent启动某个Activity">
<intent android:action="android.intent.action.VIEW"
android:data="http://www.baidu.com"/> //此处为Intent 的Data属性，Data的一般应用
</header>
</preference-headers>

设置 Preference内部需要改动的参数，掌握如何创建此Preference参数，1.Opens a wizard to help create a new Android XML File ，第四个按钮 2. 选择Preference ，并选择根元素为PreferenceScreen，单机Finish ，而后通过Add 添加自己需要的参数，在xml文件里给其布置

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<RingtonePreference
android:ringtoneType="all"
android:title="设置铃声"
android:summary="选择铃声"
android:showDefault="true"
android:key="ring_key"
android:showSilent="true" >
</RingtonePreference>

<PreferenceCategory android:title="个人信息设置组">
<EditTextPreference
android:key="name"
android:title="填写用户名"
android:summary="填写您的用户名"
android:dialogTitle="您所使用的用户名为："/>
<ListPreference
android:key="gendar"
android:title="性别"
android:summary="选择您的性别"
android:dialogTitle="ListPreference"
android:entries="@array/gendar_name_list"
android:entryValues="@array/gendar_value_list"
/>
</PreferenceCategory>
<PreferenceCategory
android:title="系统功能设置组">
<CheckBoxPreference
android:key="autoSave"
android:title="自动保存进度"
android:summaryOn="自动保存：开启"
android:summaryOff="自动保存：关闭"
android:defaultValue="true"/>
</PreferenceCategory>
</PreferenceScreen>

PreferenceActivityTest 界面代码：

package com.example.preferenceactivityapi;

import java.util.List;

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.os.Build;
import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
import android.widget.Button;
import android.widget.Toast;

public class PreferenceActivityTest extends PreferenceActivity{
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
if(hasHeaders()){
Button button=new Button(this);
button.setText("设置操作");
setListFooter(button);
}
}
public void onBuildHeaders(List<Header> target){
loadHeadersFromResource(R.layout.preference_headers, target);
}
public static class Prefs1Fragment extends PreferenceFragment{
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preferences); // 此 Fragment 为加载 Preference 布局参数 addPreferenceFromResource（）加载参数布局界面，自动保存设置。
}
}
public static class Prefs2Fragment extends PreferenceFragment{
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.display_prefs);
String website=getArguments().getString("website");
Toast.makeText(getActivity(), "网站域名为："+website, Toast.LENGTH_LONG).show();
}
}
}

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