1.建立LayoutInflater例項

有兩種方式
1.

LayoutInflater layoutInflater= LayoutInflater.from(MainActivity.this);

LayoutInflater layoutInflater= (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

2.在activity_main中建立父佈局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/rl_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    
</RelativeLayout>
 

3.建立button子佈局

<?xml version="1.0" encoding="utf-8"?>
    <Button xmlns:android="http://schemas.android.com/apk/res/android"
        android:text="Button"
        android:layout_width="300dp"
        android:layout_height="wrap_content">
    </Button>

4.給子佈局新增到父佈局中

package yuexia.com.customview;

import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.RelativeLayout;

public class MainActivity extends AppCompatActivity {

    private RelativeLayout rl_content;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        rl_content = (RelativeLayout) this.findViewById(R.id.rl_content);
        LayoutInflater inflater = LayoutInflater.from(MainActivity.this);
        LayoutInflater layoutInflater= (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        /*
        * 子元素屬性的實現的兩種方式
        * 1.root新增父元素
        * 2.給子元素添加布局
        * */
        View view=layoutInflater.inflate(R.layout.button,rl_content,true);
//        rl_content.addView(view);
        /*
        * 關於inflate的使用
        * 1.inflate的方法中root和attachToRoot分別不為空和true的時候就會新增view不需要再addView()
        * 2.新增merge時root和attachToRoot分別必須不為空和必須為true,所以也就用不到addView()
        * */
    }
}

 

5.具體不太清楚的可以看看這位大佬的

https://blog.csdn.net/vv_bug/article/details/52600758