官方Databinding常用的一些方法

一.公用的实体类工具类

package com.example.administrator.databindtext12225;

import android.databinding.ObservableField;
import android.databinding.ObservableInt;

public class Animal {
public final ObservableField<String> field = new ObservableField<>();
public final ObservableInt age = new ObservableInt();
}

package com.example.administrator.databindtext12225;

import android.databinding.BaseObservable;
import android.databinding.Bindable;

/**
* Created by Administrator on 2016/12/25 0025.
*/
public class User extends BaseObservable{
private String name;
private String address;
private int age;
@Bindable
public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
//和bindable配对使用
//        notifyPropertyChanged(com.example.administrator.databindtext.BR.name);
notifyPropertyChanged(com.example.administrator.databindtext12225.BR.name);
}
@Bindable
public String getAddress() {
return address;
}

public void setAddress(String address) {
this.address = address;
notifyPropertyChanged(com.example.administrator.databindtext12225.BR.address);
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}
}

package com.example.administrator.databindtext12225.other;

import android.databinding.BaseObservable;

/**
* Created by Administrator on 2016/12/25 0025.
*/
public class User extends BaseObservable{
private String daxiongName;
private String daxiongAddress;
private int daxiongAge;
public String getDaxiongName() {
return daxiongName;
}

public void setDaxiongName(String daxiongName) {
this.daxiongName = daxiongName;
}

public String getDaxiongAddress() {
return daxiongAddress;
}

public void setDaxiongAddress(String daxiongAddress) {
this.daxiongAddress = daxiongAddress;
}

public int getDaxiongAge() {
return daxiongAge;
}

public void setDaxiongAge(int daxiongAge) {
this.daxiongAge = daxiongAge;
}
}

import android.databinding.BaseObservable;
import android.databinding.ObservableBoolean;
import android.databinding.ObservableField;

/**
* Created by Administrator on 2016/12/25 0025.
*/
public class Student extends BaseObservable{
public ObservableField<String> stuName = new ObservableField<>();
public ObservableBoolean isMan = new ObservableBoolean();
private String stuAge;

public String getStuAge() {
return stuAge;
}

public void setStuAge(String stuAge) {
this.stuAge = stuAge;
}
}

package com.example.administrator.databindtext12225;

import android.databinding.DataBindingUtil;
import android.databinding.ViewDataBinding;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;

/**
* Created by Administrator on 2016/12/25 0025.
*/
public class MyAdapter extends RecyclerView.Adapter {

private ArrayList<Student> mData = new ArrayList<>();

public  MyAdapter(ArrayList<Student> data) {
mData.addAll(data);
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
ViewDataBinding binding = DataBindingUtil.inflate(LayoutInflater
.from(parent.getContext()), R.layout.item_recycleview, parent, false);
ViewHolder holder = new ViewHolder(binding.getRoot());
holder.setBinding(binding);
return holder;
}

/**
* ViewDataBinding是我们之前用的那些binding的父类，只有自动生成的那些子类才会有setXXX方法，那现在我们需要在ViewDataBinding中设置变量咋办？这个类为我们提供了setVariable去设置变量，第一个参数是我们的变量名的引用，第二个是我们要设置的值
*当数据改变时，binding会在下一帧去改变数据，如果我们需要立即改变，就去调用executePendingBindings方法
*  */
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
((ViewHolder)holder).getBinding().setVariable(com.example.administrator.databindtext12225.BR.stu,mData.get(position));
((ViewHolder)holder).getBinding().executePendingBindings();
((ViewHolder)holder).getBinding().setVariable(com.example.administrator.databindtext12225.BR.drawableId,R.mipmap.ic_launcher);
}

@Override
public int getItemCount() {
return mData.size();
}

class ViewHolder extends RecyclerView.ViewHolder {

private ViewDataBinding binding;

public ViewHolder(View itemView) {
super(itemView);
}

public void setBinding(ViewDataBinding binding) {
this.binding = binding;
}

public ViewDataBinding getBinding() {
return this.binding;
}
}
}

package com.example.administrator.databindtext12225;

import android.databinding.BindingAdapter;
import android.widget.ImageView;

/**
* Created by Administrator on 2016/12/25 0025.
*/
public class Utils {
@BindingAdapter({"bind:image"})
public static void imageLoader(ImageView imageView, int  drawableId) {
imageView.setBackgroundResource(drawableId);
}
}

二.Mainactivity.java

/**
* 这里主要写的是怎么把
* 1.对象  和 基本数据类型  跟view绑定
* 2.给include的布局  传递对象
* 3.@{user.displayName ?? user.lastName  如果不是null  就是自身，如果是null就是user.lastName
* 4.
* <TextView android:layout_width="wrap_content"
* android:layout_height="wrap_content"
* android:text="@{user.firstName, default=超哥}"/>
* 5.如何 import 相同类名的class
*/
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private User mUser;
private com.example.administrator.databindtext12225.other.User mOtherUser;
private ActivityMainBinding mBinding;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);
mUser = new User();
mUser.setName("超哥");
mUser.setAddress("北一峰");

mOtherUser = new com.example.administrator.databindtext12225.other.User();
mOtherUser.setDaxiongName("我是大雄");
mOtherUser.setDaxiongAddress("南一峰");

mBinding.setUser(mUser);
mBinding.setOtheruser(mOtherUser);

//editText 输入完成改变对象
mBinding.btOtherUserConfirm.setOnClickListener(this);
mBinding.btUserConfirm.setOnClickListener(this);

//跳转到SecondActivity
mBinding.btJump.setOnClickListener(this);
}

@Override
public void onClick(View view) {
if (view == mBinding.btUserConfirm) {
System.out.println("xcqw btUserConfirm   name" + mBinding.etUserName.getText().toString() + "  address  " + mBinding.etUserAddress.getText().toString());
//        方法1：    这种不会立即改变View  （user没有继承baseObservale）
//            mUser.setName(mBinding.etUserName.getText().toString());
//            mUser.setAddress(mBinding.etUserAddress.getText().toString());

//        方法2：  这种就会立即改变View(也就是重新设置一个user)
//            User user = new User();
//            user.setName(mBinding.etUserName.getText().toString());
//            user.setAddress(mBinding.etUserAddress.getText().toString());
//            mBinding.setUser(user);

//        方法3：    会立即改变View
//            1.user extends baseobservable
//            2.在get方法上@bindable
//            3.在set方法notifyPropertyChanged
mUser.setName(mBinding.etUserName.getText().toString());
mUser.setAddress(mBinding.etUserAddress.getText().toString());

} else if (view == mBinding.btOtherUserConfirm) {
//        方法1：  这种不会立即改变View
//            System.out.println("xcqw btOtherUserConfirm  name"+mBinding.etOtherUserName.getText().toString()+"  address  "+mBinding.etOtherUserAddress.getText().toString());
//            mOtherUser.setDaxiongName(mBinding.etOtherUserName.getText().toString());
//            mOtherUser.setDaxiongAddress(mBinding.etOtherUserAddress.getText().toString());

//        方法2：  这种就会立即改变View
com.example.administrator.databindtext12225.other.User user = new com.example.administrator.databindtext12225.other.User();
user.setDaxiongName(mBinding.etOtherUserName.getText().toString());
user.setDaxiongAddress(mBinding.etOtherUserAddress.getText().toString());
mBinding.setOtheruser(user);

} else if (view == mBinding.btJump) {
startActivity(new Intent(MainActivity.this, SecondActivity.class));
}
}
}

<?xml version="1.0" encoding="utf-8"?>
<layout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:bind="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">

<data>

<variable
name="user"
type="com.example.administrator.databindtext12225.User">
</variable>

<!--因为type="User"都为User类，会导致不知道到那个包，所以可以通过alias属性重命名type的类型-->
<import
alias="Other"
type="com.example.administrator.databindtext12225.other.User"/>

<variable
name="otheruser"
type="Other">
</variable>

</data>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<include
layout="@layout/include_layout"
bind:user="@{user}"
/>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
tools:context="com.example.administrator.databindtext12225.MainActivity">

<TextView
android:id="@+id/tv_user_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`userName`+user.name}"/>

<TextView
android:id="@+id/tv_user_address"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`userAddress`+user.address}"/>
</LinearLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
tools:context="com.example.administrator.databindtext12225.MainActivity">

<TextView
android:id="@+id/tv_other_user_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`otherUserName`+otheruser.daxiongName}"/>

<TextView
android:id="@+id/tv_other_user_address"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`otherUserAddress`+otheruser.daxiongAddress}"/>
</LinearLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">

<EditText
android:id="@+id/et_user_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="请输入user的name"/>

<EditText
android:id="@+id/et_user_address"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="请输入user的address"/>

<Button
android:id="@+id/bt_user_confirm"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="确认输入，改变userView"/>
</LinearLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">

<EditText
android:id="@+id/et_other_user_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="请输入otheruser的name"/>

<EditText
android:id="@+id/et_other_user_address"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="请输入otheruser的address"/>

<Button
android:id="@+id/bt_other_user_confirm"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="确认输入，改变otherUserView"/>
</LinearLayout>

<Button
android:id="@+id/bt_jump"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="跳到SecondActivity"/>

</LinearLayout>
</layout>

三.SecondActivity.java

**
* 1.一些特殊字符的转义，<String>    左右尖括号的写法
* 2.对象绑定的另外一种方法 属性都用observal
* 3.arrayList，map绑定的方法
* 4.map的两种写法
* normalMap.get(`age`)
* map[`name`]
* 5.在布局文件中可以用``拼接字符串
* */
public class SecondActivity extends AppCompatActivity {

private ActivitySecondBinding mBinding;
private ObservableArrayList<com.example.administrator.databindtext12225.other.User> arrayList;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mBinding = DataBindingUtil.setContentView(SecondActivity.this, R.layout.activity_second);

//第一部分  普通的写法不会直接互相绑定
//        final ArrayList<String> normalList = new ArrayList<>();
//        normalList.add("first");
//        normalList.add("second");
//        mBinding.setNormalList(normalList);
//
//        final Map<String, String> normalMap = new HashMap<>();
//        normalMap.put("name", "zhangsan");
//        normalMap.put("age", "40");
//        mBinding.setNormalMap(normalMap);
//
//        final String[] normalArrays = {"lisi", "laowang"};
//        mBinding.setNormalArrays(normalArrays);

//第二部分 这么写才会互相绑定
final Animal animal = new Animal();
animal.field.set("cat");
animal.age.set(2);
mBinding.setAnimal(animal);

arrayList = new ObservableArrayList<>();
for (int i=0;i<2;i++){
com.example.administrator.databindtext12225.other.User user = new com.example.administrator.databindtext12225.other.User();
user.setDaxiongName("大熊"+i+"号");
arrayList.add(user);
}
mBinding.setUserList(arrayList);

final ObservableArrayList<String> list = new ObservableArrayList<>();
list.add("daxiong");
list.add("daxiong2");
mBinding.setList(list);

final ObservableArrayMap<String, String> map = new ObservableArrayMap<>();
map.put("name","Tom");
map.put("age","4");
mBinding.setMap(map);

mBinding.btChangeValue.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//                第一部分  这么写不会互相绑定
//                normalList.set(0,"hehe");
//                normalList.set(1,"haha");
//                normalMap.put("name","sam");
//                normalMap.put("age","5");
//                normalArrays[0] = "zhaosi";

//第二部分
//作用类型  对象的bindable
animal.field.set("dog");
animal.age.set(4);
list.set(0,"cat");
list.set(1,"dog");
map.put("name","Sam");
map.put("age","5");
//other/user中的属性需要加上  notifyPropertyChanged(BR.daxiongName); 才会生效，否则没用
arrayList.get(0).setDaxiongName("大熊一号改装过");
arrayList.get(1).setDaxiongName("大熊二号改装过");
}
});
mBinding.btJumpThirdactivity.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
startActivity(new Intent(SecondActivity.this,ThirdActivity.class));
}
});
}

}

<?xml version="1.0" encoding="utf-8"?>
<layout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.administrator.databindtext12225.SecondActivity">

<data>
<import type="java.util.ArrayList" />
<import type="java.util.Map" />
<import type="java.lang.String" />
<import type="com.example.administrator.databindtext12225.other.User" />
<variable
name="secondActivity"
type="com.example.administrator.databindtext12225.SecondActivity">
</variable>

<!--第一部分-->

<variable
name="normalList"
type="ArrayList<String>"/>

<!--泛型的支持会在编译时期报红线，但是是可以直接运行的
但是需要通过转义字符才行，如：<数据类型> 或者<数据类型>-->
<!--< <  > >   貌似这个gt可以直接用>  但是<必须被替换-->

<variable
name="normalMap"
type="Map<String,String>" />

<variable
name="normalArrays"
type="String[]" />

<!--第一部分结束-->

<!--这么写一直报错，非要写的跟下面一样，把user拿出去！！！！-->
<!--<variable-->
<!--name="user"-->
<!--type="com.example.administrator.databindtext12225.User">-->
<!--</variable>-->
<variable
name="user"
type="User">
</variable>

<variable
name="animal"
type="com.example.administrator.databindtext12225.Animal">
</variable>

<variable
name="userList"
type="android.databinding.ObservableArrayList<User>"/>

<variable
name="list"
type="android.databinding.ObservableArrayList<String>"/>

<variable
name="map"
type="android.databinding.ObservableArrayMap<String,String>"/>

</data>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>

<!--第一部分-->
<!--<TextView-->
<!--android:layout_width="wrap_content"-->
<!--android:layout_height="wrap_content"-->
<!--android:text="@{normalList[0]}"/>-->

<!--<TextView-->
<!--android:layout_width="wrap_content"-->
<!--android:layout_height="wrap_content"-->
<!--android:text="@{normalList[1]}"/>-->
<!--<!–!!!!! `````这个符号可以凭借字符串–>-->
<!--<TextView-->
<!--android:layout_width="wrap_content"-->
<!--android:layout_height="wrap_content"-->
<!--android:text="@{normalMap.get(`age`)}"/>-->
<!--<TextView-->
<!--android:layout_width="wrap_content"-->
<!--android:layout_height="wrap_content"-->
<!--android:text="@{normalArrays[0]}"/>-->
<!--第一部分结束-->

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`animal.filed`+animal.field}" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`animal.age`+String.valueOf(animal.age)}" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`list[0]`+list[0]}" />
<!--Map集合既可以通过map[key]的方式，也可以通过调用API-->
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`list[1]`+list[1]}" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`map[name]`+map[`name`]}" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`otheruserList[0]name`+userList[0].getDaxiongName}" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{`otheruserList[1]name`+userList[1].getDaxiongName}" />
<Button
android:id="@+id/bt_change_value"
android:layout_width="wrap_content"
android:text="改变数据"
android:layout_height="wrap_content" />
<Button
android:id="@+id/bt_jump_thirdactivity"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="跳到ThirdActivity"/>

</LinearLayout>

</layout>

四.ThirdActivity.java

/**
* 1.点击事件的几种写法
* */
public class ThirdActivity extends AppCompatActivity {

private ActivityThirdBinding mBinding;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mBinding = DataBindingUtil.setContentView(ThirdActivity.this, R.layout.activity_third);
User user = new User();
user.setName("我是第三个Activity");
mBinding.setUser(user);

//        第二种点击事件写法
mBinding.setClickEvent(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(ThirdActivity.this, "xcqw 我是第二种点击事件写法", Toast.LENGTH_SHORT).show();
}
});
//        第三种点击事件写法
mBinding.setMyEvent(new MyEventListener() {
@Override
public void clickEventOne(View view) {
Toast.makeText(ThirdActivity.this, "xcqw 我是第三种写法  clickEventOne", Toast.LENGTH_SHORT).show();
}

@Override
public void clickEventTwo(View view) {
Toast.makeText(ThirdActivity.this, "xcqw 我是第三种写法  clickEventTwo", Toast.LENGTH_SHORT).show();
}

@Override
public void clickEventThree(User user) {
Toast.makeText(ThirdActivity.this, "xcqw 我是第三种写法  clickEventTwo username"+user.getName(), Toast.LENGTH_SHORT).show();
}
});

mBinding.btJumpFouractivity.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
startActivity(new Intent(ThirdActivity.this,FourActivity.class));
}
});
}

public void firstMethodClick(View view){
//        这种传统的点击事件写法还有好几种
Toast.makeText(ThirdActivity.this, "xcqw 我是第一种写法 firstMethodClick", Toast.LENGTH_SHORT).show();
}
}

<?xml version="1.0" encoding="utf-8"?>
<layout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.administrator.databindtext12225.SecondActivity">

<data>

<variable
name="view"
type="android.view.View">
</variable>

<variable
name="user"
type="com.example.administrator.databindtext12225.User"/>

<variable
name="clickEvent"
type="android.view.View.OnClickListener"
/>

<variable
name="myEvent"
type="com.example.administrator.databindtext12225.MyEventListener"/>

</data>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>

<Button
android:id="@+id/bt_first_method"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="firstMethodClick"
android:text="第一种传统写法"/>
<Button
android:id="@+id/bt_second_method"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="@{clickEvent}"
android:text="第二种点击方式"/>
<Button
android:id="@+id/bt_third_method"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="@{myEvent.clickEventOne}"
android:text="第三种新式写法"/>
<!--不知道() -> myEvent.clickEventThree(user) 代表什么意思-->
<Button
android:id="@+id/bt_third_method_two"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="@{() -> myEvent.clickEventThree(user)}"
android:text="第三种新式写法有入参"/>

<Button
android:id="@+id/bt_jump_fouractivity"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="跳到fourActivity"/>
</LinearLayout>

</layout>

五.FourActivitiy.java

package com.example.administrator.databindtext12225;

import android.databinding.DataBindingUtil;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.view.View;

import com.example.administrator.databindtext12225.databinding.ActivityFourBinding;

import java.util.ArrayList;
/**
* 1.recycleView
* 2.自定义binding de set方法
*      （1）现在utils方法写一个@BindingAdapter({"bind:image"})
public static void imageLoader(ImageView imageView, int  drawableId) {
imageView.setBackgroundResource(drawableId);
（2）然后在布局里面用上
<variable
name="drawableId"
type="int" />

<ImageView
android:id="@+id/img"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:image="@{drawableId}"/>
（3）实际用的地方
((ViewHolder)holder).getBinding().setVariable(com.example.administrator.databindtext12225.BR.drawableId,R.mipmap.ic_launcher);

// @BindingAdapter({"bind:imageUrl", "bind:error"})
// public static void loadImage(ImageView view, String url, Drawable error) {
// Picasso.with(view.getContext()).load(url).error(error).into(view);
// }

* */
public class FourActivity extends AppCompatActivity {

private ActivityFourBinding mBinging;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_four);
mBinging = DataBindingUtil.setContentView(FourActivity.this, R.layout.activity_four);
mBinging.recycle.setLayoutManager(new LinearLayoutManager(this,
LinearLayoutManager.VERTICAL, false));

final ArrayList<Student> mData = new ArrayList<>();
for (int i = 0;i<10;i++){
Student stu = new Student();
stu.stuName.set("我是学生    "+i);
mData.add(stu);
}
mBinging.recycle.setAdapter(new MyAdapter(mData));
mBinging.btChangeData.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
mData.get(4).stuName.set("hahahhahaha");
//普通写法是没用
//1  stu 中写bindable
//2  把String  写成 observableField<String>
}
});
}
}

<?xml version="1.0" encoding="utf-8"?>
<layout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.administrator.databindtext12225.FourActivity">

<data>

</data>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>

<android.support.v7.widget.RecyclerView
android:id="@+id/recycle"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v7.widget.RecyclerView>

<Button
android:id="@+id/bt_change_data"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="点我改变数据"/>
</LinearLayout>

</layout>