listView,expandListView 如何代码设置margin

原理：由于android layout的的原理可见下方链接

view layout原理

ANDROID自定义视图——onLayout源码

解决方法：找出view 或viewGroup 所在的父布局，获取父布局的layoutParams

一 ViewGroup设置margin

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activity.DeviceSimpleDetailActivity">

 
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycleView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/titlebar"
        android:layout_marginBottom="55dp" />

    <LinearLayout
        android:id="@+id/ll_buttons"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_marginBottom="@dimen/margin10"
        android:background="@color/white"
        android:layout_alignParentBottom="true"
        android:orientation="horizontal"
       >

        <Button
            android:id="@+id/bt_left"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_marginRight="1dp"
            android:layout_weight="1"
            android:background="@color/blue"
            android:text="@string/pass"
            android:textColor="@color/white"
            android:textSize="@dimen/text_size_mid" />

        <Button
            android:id="@+id/bt_right"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@color/blue"
            android:text="@string/reject"
            android:textColor="@color/white"
            android:textSize="@dimen/text_size_mid" />
    </LinearLayout>

</RelativeLayout>

我们需要为recycleView 设置marginBottom，xml里设置的是55dp,在底部linearLayout 设置为GONE的时候需要把marginbottom设置为0，由于recycleView的父布局是RelativeLayout,具体代码如下：

ll_buttons.setVisibility(View.GONE);
            RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) recycleView.getLayoutParams();
            lp.setMargins(0,0,0,0);
            recycleView.setLayoutParams(lp);

二 View设置margin,例如imageView

RelativeLayout.LayoutParams lp1 =new RelativeLayout.LayoutParams( imageView.getLayoutParams());
lp1.setMargins(0,0,0,0);
imageView.setLayoutParams(lp1);