Android-Fragment – 小飞侠

1.fragment介绍

fragment总是被嵌入到Activity里 fragment要添加到ViewGroup里

fragment是在android3.0的时候被引入的.

代码实现

1.在布局声明

<? xml version = "1.0" encoding = "utf-8" ?>
< LinearLayout xmlns : android = "http://schemas.android.com/apk/res/android"
android : orientation = "horizontal"
android : layout_width = "match_parent"
android : layout_height = "match_parent" >
< fragment android : name = "itheima.day12.Test1Fragment"
android : id = "@+id/list"
android : layout_weight = "1"
android : layout_width = "0dp"
android : layout_height = "match_parent" />
< fragment android : name = "itheima.day12.Test2Fragment"
android : id = "@+id/viewer"
android : layout_weight = "2"
android : layout_width = "0dp"
android : layout_height = "match_parent" />
</ LinearLayout >

2.声明fragment 需要重写onCreateView方法

//创建了一个fragment 代表一个页面
public class Test1Fragment extends Fragment {
//通过下面这个方法加载布局
@Override
public View onCreateView ( LayoutInflater inflater , ViewGroup container , Bundle savedInstanceState ) {
//加载布局通过打气筒加载
return inflater . inflate ( R . layout . fragment_test1 , null );
}
}

2.动态添加fragment

public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate ( Bundle savedInstanceState ) {
super . onCreate ( savedInstanceState );
setContentView ( R . layout . activity_main );
//1.获取手机宽高
WindowManager wm = ( WindowManager ) getSystemService ( WINDOW_SERVICE );
int width = wm . getDefaultDisplay (). getWidth ();
int height = wm . getDefaultDisplay (). getHeight ();
//2.获取一个fragment的管理者
FragmentManager fragmentManager = getFragmentManager ();
//2.1 开启fragment事务
FragmentTransaction fragmentTransaction = fragmentManager . beginTransaction ();
//3.判断手机状态是横屏还是竖屏
if ( height > width ){
//说明是竖屏加载一个页面参数1:android.代表系统定义好的一些id 理解成是当前手机窗口
fragmentTransaction . replace ( android . R . id . content , new Test1Fragment ());
} else {
//说明是横屏加载另外一个页面
fragmentTransaction . replace ( android . R . id . content , new Test2Fragment ());
}
//4.最后一步记得提交事务
fragmentTransaction . commit ();
}
}

3.通过v4包中的fragment支持低版本.

兼容低版本就是使用V4包中的fragment .

注意地方:在获取fragm管理者的方式不一样了

FragmentManager supportFragmentManager = getSupportFragmentManager ();

4.通过fragment模拟一个微信主页面

1.在布局中声明UI

<? xml version = "1.0" encoding = "utf-8" ?>
< RelativeLayout xmlns : android = "http://schemas.android.com/apk/res/android"
xmlns : tools = "http://schemas.android.com/tools"
android : id = "@+id/activity_main"
android : layout_width = "match_parent"
android : layout_height = "match_parent"
tools : context = "itheima.wechat.MainActivity" >
< LinearLayout
android : id = "@+id/ll"
android : layout_width = "match_parent"
android : layout_height = "match_parent"
android : orientation = "vertical" >
</ LinearLayout >
< LinearLayout
android : layout_width = "match_parent"
android : layout_height = "wrap_content"
android : layout_alignParentBottom = "true"
android : orientation = "horizontal" >
< Button
android : id = "@+id/btn_wx"
android : layout_width = "0dp"
android : layout_height = "wrap_content"
android : layout_weight = "1"
android : text = "消息" />
< Button
android : id = "@+id/btn_contact"
android : layout_width = "0dp"
android : layout_height = "wrap_content"
android : layout_weight = "1"
android : text = "联系人" />
< Button
android : id = "@+id/btn_discover"
android : layout_width = "0dp"
android : layout_height = "wrap_content"
android : layout_weight = "1"
android : text = "发现" />
< Button
android : id = "@+id/btn_mine"
android : layout_width = "0dp"
android : layout_height = "wrap_content"
android : layout_weight = "1"
android : text = "我" />
</ LinearLayout >
</ RelativeLayout >

2.声明四个fragment,每个fragmen分别代表一个页面

3.根据UI写对应逻辑

public class MainActivity extends AppCompatActivity implements View . OnClickListener {
@Override
protected void onCreate ( Bundle savedInstanceState ) {
super . onCreate ( savedInstanceState );
setContentView ( R . layout . activity_main );
//1.找的我们关心控件
Button btn_contact = ( Button ) findViewById ( R . id . btn_contact );
Button btn_wx = ( Button ) findViewById ( R . id . btn_wx );
Button btn_discover = ( Button ) findViewById ( R . id . btn_discover );
Button btn_mine = ( Button ) findViewById ( R . id . btn_mine );
//2.给按钮设置点击事件
btn_contact . setOnClickListener ( this );
btn_wx . setOnClickListener ( this );
btn_discover . setOnClickListener ( this );
btn_mine . setOnClickListener ( this );
}
//具体判断一下点击按个按钮
@Override
public void onClick ( View view ) {
//1.获取fragment管理者
FragmentManager fragmentManager = getFragmentManager ();
//2.开启事务
FragmentTransaction fragmentTransaction = fragmentManager . beginTransaction ();
switch ( view . getId ()){
case R . id . btn_wx : //点击消息按钮
fragmentTransaction . replace ( R . id . ll , new WxFragment ());
break ;
case R . id . btn_contact : //点击了联系人按钮
fragmentTransaction . replace ( R . id . ll , new ContactFragment ());
break ;
case R . id . btn_discover : //点击发现按钮
fragmentTransaction . replace ( R . id . ll , new DiscoverFragment ());
break ;
case R . id . btn_mine : //点击我按钮
fragmentTransaction . replace ( R . id . ll , new MineFragment ());
break ;
}
//3.提交事务
fragmentTransaction . commit ();
}
}

5.fragment生命周期

在实际开发中只需要重写onCreateView 和 onDestroy方法就可够用了,在onCreateView方法里面初始化控件.在ondestroy方法里面做扫尾的工作.比如解绑服务释放资源.

6.fragment之间通信

fragment之间公共桥梁—->Activity.

7.样式和主题

主题和样式定义的方式是一样的都是在res下style.xml文件里面定义

样式和主题作用范围不一样,样式一般应用在控件上,主题一般应用在application或者是activity上面.

8.国际化

周杰伦 jay jj:林俊杰 i18n—->国际化—->

在res目录下创建各个缩略语言目录就可以了

9.应用的反编译

apktools 对apk资源(图片布局清单文件)进行反编译

dex2jar —>jd.exe

反编译步骤 —>直接使用android的逆向助手来反编译

10.属性动画

public class MainActivity extends AppCompatActivity {
private ImageView iv ;
@Override
protected void onCreate ( Bundle savedInstanceState ) {
super . onCreate ( savedInstanceState );
setContentView ( R . layout . activity_main );
//1.找到控件
iv = ( ImageView ) findViewById ( R . id . iv );
//2.给iv设置点击事件
iv . setOnClickListener ( new View . OnClickListener () {
@Override
public void onClick ( View view ) {
Toast . makeText ( MainActivity . this , "你点不到我" , Toast . LENGTH_SHORT ). show ();
}
});
// iv.setAlpha();
// iv.setRot
// iv.setScaleY();
// iv.setTranslationX();
}
//点击按钮使用属性动画实现透明动画效果
public void click1 ( View view ) {
//1.获取ObjectAnimator 实例通过类提供的静态方法参1:目标(谁执行动画) //参数2:属性名
ObjectAnimator oa = ObjectAnimator . ofFloat ( iv , "alpha" , 1.0f , 0.8f , 0 , 7f , 0.4f , 0.0f , 0.5f , 0 , 9f , 1.0f );
//2.设置动画执行时长
oa . setDuration ( 2000 );
//3.启动动画
oa . start ();
}
//点击按钮使用属性动画实现旋转动画效果
public void click2 ( View view ) {
//1.获取ObjectAnimator 实例通过类提供的静态方法参1:目标(谁执行动画) //参数2:属性名
ObjectAnimator oa = ObjectAnimator . ofFloat ( iv , "rotation" , 0 , 90 , 180 , 360 );
//2.设置动画执行时长
oa . setDuration ( 2000 );
//3.启动动画
oa . start ();
}
//点击按钮使用属性动画实现缩放动画效果
public void click3 ( View view ) {
//1.获取ObjectAnimator 实例通过类提供的静态方法参1:目标(谁执行动画) //参数2:属性名
ObjectAnimator oa = ObjectAnimator . ofFloat ( iv , "scaleX" , 1.0f , 2.0f , 3.0f , 4.0f );
//2.设置动画执行时长
oa . setDuration ( 2000 );
//3.启动动画
oa . start ();
}
//点击按钮使用属性动画实现位移动画效果
public void click4 ( View view ) {
//1.获取ObjectAnimator 实例通过类提供的静态方法参1:目标(谁执行动画) //参数2:属性名
ObjectAnimator oa = ObjectAnimator . ofFloat ( iv , "translationX" , 0 , 10 , 30 , 100 );
//2.设置动画执行时长
oa . setDuration ( 2000 );
//3.启动动画
oa . start ();
}
//让前面几个动画一起执行
public void click5 ( View view ) {
//1,创建动画合集
AnimatorSet set = new AnimatorSet ();
//2.创建不同动画效果
ObjectAnimator oa1 = ObjectAnimator . ofFloat ( iv , "alpha" , 1.0f , 0.8f , 0 , 7f , 0.4f , 0.0f , 0.5f , 0 , 9f , 1.0f );
ObjectAnimator oa2 = ObjectAnimator . ofFloat ( iv , "rotation" , 0 , 90 , 180 , 360 );
ObjectAnimator oa3 = ObjectAnimator . ofFloat ( iv , "scaleX" , 1.0f , 2.0f , 3.0f , 4.0f );
ObjectAnimator oa4 = ObjectAnimator . ofFloat ( iv , "translationX" , 0 , 10 , 30 , 100 );
//3.让oa1 oa2 oa3 oa4 一起飞
// set.playTogether(oa1,oa2,oa3,oa4);
//3.1 让oa1 oa2 oa3 oa4 按顺序执行
set . playSequentially ( oa1 , oa2 , oa3 , oa4 );
//4.谁来执行动画
set . setTarget ( iv );
//5.设置动画执行时长
set . setDuration ( 2000 );
//6.启动动画
set . start ();
}
}

属性动画会改变控件真实的坐标.

11.通知

1.给用户友好提示的方式: 1Toast 2 对话框 3,通知

2.我们学过的manager: DriverManager,SmsManager,WindowManager,

TelephonyManager

,FragmentManager,

NotificationManager

PackageManager ActivityManager

public class MainActivity extends AppCompatActivity {
private NotificationManager nm ;
@Override
protected void onCreate ( Bundle savedInstanceState ) {
super . onCreate ( savedInstanceState );
setContentView ( R . layout . activity_main );
}
//点击按钮弹出通知
public void click1 ( View view ) {
//1.获取通知的管理者
nm = ( NotificationManager ) getSystemService ( NOTIFICATION_SERVICE );
//1.0创建意图
Intent intent = new Intent ();
//1.1给小芳打个电话问问清楚
intent . setAction ( Intent . ACTION_CALL );
intent . setData ( Uri . parse ( "tel:" + 110 ));
//1.2 构造pendingIntent
PendingIntent pi = PendingIntent . getActivities ( this , 0 , new Intent []{ intent }, PendingIntent . FLAG_ONE_SHOT );
//2.构造notification 链式调用:每调用方法返回值都是一样的
Notification noti = new Notification . Builder ( this )
. setContentTitle ( "小芳" ) //设置通知标题
. setContentText ( "老地方件" ) //设置标题描述
. setSmallIcon ( R . mipmap . ic_launcher ) //设置小图标
. setLargeIcon ( BitmapFactory . decodeResource ( getResources (), R . mipmap . ic_launcher )) //设置大图标
. setContentIntent ( pi ) //点击通知做的事情
. setDefaults ( Notification . DEFAULT_ALL )
. build ();
//2.弹出通知
nm . notify ( 10 , noti );
}
//点击按钮关闭通知
public void click2 ( View view ) {
nm . cancel ( 10 );
}

原文链接：https://blog.csdn.net/NervousDing/article/details/80304597