LayoutInflater中inflate方法的简单使用

绝地灬酷狼 2022-07-21 12:11 171阅读 0赞

有三种方法可以获取layoutinflater的实例:

LayoutInflater layout=this.getLayoutInflater();//method1
    LayoutInflater layout=LayoutInflater.from(this);//mrthod2
    this.getSystemService(this.LAYOUT_INFLATER_SERVICE);//method3
    有2个布局:
    <pre name="code" class="html"><?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:id="@+id/myLayout2">
    
        <TextView
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:gravity="center"
            android:text="这是主界面" />
    
    </LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
    
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="300dp"
    
        android:orientation="vertical" >
    
        <TextView
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:gravity="center"
            android:text="这是辅助界面" />
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:id="@+id/myImage"/>
    </LinearLayout>

现在来测试一下LayoutInflater().inflate的几种用法

1.inflate(view, null)

LayoutInflater layout= (LayoutInflater) this.getSystemService(this.LAYOUT_INFLATER_SERVICE);//method3
            View myView=layout.inflate(R.layout.other,null);
    <pre name="code" class="java">ImageView imageView= (ImageView) myView.findViewById(R.id.myImage);
            imageView.setImageResource(R.drawable.a);
            setContentView(myView);

现在来看一下结果:

2.inflate(view, root, false)

View view = (LinearLayout) getLayoutInflater().inflate(R.layout.activity_main2,
                    null);
            LayoutInflater layout= (LayoutInflater) this.getSystemService(this.LAYOUT_INFLATER_SERVICE);
     View myView=layout.inflate(R.layout.other, (ViewGroup) view,false);
            ImageView imageView= (ImageView) myView.findViewById(R.id.myImage);
            imageView.setImageResource(R.drawable.a);
            setContentView(myView);

![Center][]

3.inflate(view, root, true)

View view = (LinearLayout) getLayoutInflater().inflate(R.layout.activity_main2,
                    null);
            LayoutInflater layout= (LayoutInflater) this.getSystemService(this.LAYOUT_INFLATER_SERVICE);
     View myView=layout.inflate(R.layout.other, (ViewGroup) view,true);
            ImageView imageView= (ImageView) myView.findViewById(R.id.myImage);
            imageView.setImageResource(R.drawable.a);
            setContentView(myView);

![Center 1][]

结论:

如果不指定root参数,那么我们在把视图加载到Activity的时候,视图上的尺寸设置是没有效果的,直接会充满屏幕显示,

如果指定了root参数,但是第三个参数设置为false的时候,不会加载root视图,但是当前的布局文件中layoutparam参数会保存

如果第三个参数设置为true的时候,当前的布局会套在root布局里边,然后作为一个整体显示,并且layoutparam参数也是会保留的

以上是本人做的一些小测试,如有错误,还请指正...

[Center]: /images/20220720/16ae79783e944d6bbe62dc55bfa00064.png
[Center 1]: /images/20220720/821b0e43181b4fb3b2097357ac92e7b6.png