最近使用databinding发现, 在布局文件中使用了<include>标签, 想要去控制标签布局文件的显示与隐藏时会出现问题.
首先进行下问题重现:
布局文件:
<?xml version="1.0" encoding="utf-8"?>
<layout>
<data>
<variable
name="activity"
type="com.example.databinding.MainActivity" />
<variable
name="testBean"
type="com.example.databinding.TestBean" />
<import type="android.view.View" />
</data>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/ll_root"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.databinding.MainActivity">
<TextView
android:layout_width="match_parent"
android:layout_height="60dp"
android:layout_gravity="center"
android:gravity="center"
android:text="Hello World!" />
<TextView
android:background="@color/colorAccent"
android:id="@+id/tv_dis"
android:layout_width="match_parent"
android:layout_height="60dp"
android:layout_gravity="center"
android:gravity="center"
android:onClick="@{v -> activity.onClick(v)}"
android:text="点击隐藏/显示include" />
<include
android:id="@+id/include"
layout="@layout/include_layout"/>
</LinearLayout>
</layout>
include 的布局:
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="@color/colorPrimary"
android:gravity="center"
android:text="我是include后的textview" />
activity中的代码:
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
TestBean testBean;
ActivityMainBinding viewDataBinding;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
viewDataBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);
testBean = new TestBean();
viewDataBinding.setVariable(BR.testBean, testBean);
viewDataBinding.setVariable(BR.activity, this);
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.tv_dis) {
testBean.setShowFlag(!testBean.getShowFlag());
viewDataBinding.include.setVisibility(testBean.getShowFlag()? View.VISIBLE : View.GONE);
}
}
}
为了更好的 debug, 我这将visiablity 属性的设置通过代码实现
显示效果:
1.png
正常情况来说, 点击隐藏按钮, 应该只有最后一条 include 之后的被隐藏, 但是目前的代码点击值, 真个 linearlayout 的布局都隐藏了, 我们通过 debug 进行查看:
2.png
我们发现了一个很奇怪的事情, include 的布局 id databinding 在寻找时找到的对应的根布局文件, ll_root, 导致整个根布局都被隐藏掉了!!!!!
所以想使用 databinding 对 include 文件进行显示控制时,我们需要采取别的策略.
解决方法
对 include 的布局文件也使用 databinding
<?xml version="1.0" encoding="utf-8"?>
<layout>
<data>
<variable
name="testBean"
type="com.example.databinding.TestBean" />
<import type="android.view.View" />
</data>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="@color/colorPrimary"
android:gravity="center"
android:text="我是include后的textview"
android:visibility="@{testBean.showFlag? View.VISIBLE : View.GONE}" />
</layout>
在引入的布局中, 通过 databinding 进行数据赋值
<?xml version="1.0" encoding="utf-8"?>
<layout>
<data>
<variable
name="activity"
type="com.example.databinding.MainActivity" />
<variable
name="testBean"
type="com.example.databinding.TestBean" />
</data>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/ll_root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.databinding.MainActivity">
.......
<include
android:id="@+id/include"
layout="@layout/include_layout"
app:testBean="@{testBean}" />
// 这里的 app:后面的内容就是在 include 布局中需要的 data 名,需要保持一致
</LinearLayout>
</layout>
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
viewDataBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);
testBean = new TestBean();
viewDataBinding.setVariable(BR.testBean, testBean);
viewDataBinding.setVariable(BR.activity, this);
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.tv_dis) {
testBean.setShowFlag(!testBean.getShowFlag());
}
}
这时候我们点击隐藏, 终于可以实现理想的效果啦~~~
AEC1FEE6-BFB9-4D5F-979D-10CB97DC216A.png
