Adding LinearLayout to a linearlayout in a FrameLayout

Question

I'm having trouble adding a linearlayout to another linearlayout inside a framelayout. The linearlayout with the button doesnt show up at all. I understand that in a framelayout the child elements stack behind each other, but im adding it to a linearlayout so shouldnt it just appear beneath the listview?

Thanks for the help

Here is the xml of the layout.

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/dragTopView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    dtlOpen="false">

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

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textStyle="bold"
            android:textSize="20sp" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center">

            <EditText
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:ems="10"
                android:padding="10dip" />

            <ImageView
                android:id="@+id/quick_icon"
                android:layout_width="35dip"
                android:layout_height="35dip"
                android:scaleType="centerCrop" />
        </LinearLayout>
    </LinearLayout>

    <LinearLayout
        android:id="@+id/contacts"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <ListView
            android:id="@+id/contactsListView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:dividerHeight="1dip" >
        </ListView>
    </LinearLayout>
</FrameLayout>

This is how i add the view programatically,

LinearLayout layout = (LinearLayout) rootView.findViewById(R.id.contacts);
LinearLayout lin = helpers.getInterfaceHelper().createDynamicButton();
layout.addView(lin);

This is the createDynamicButton function

public LinearLayout createDynamicButton() {
    final float scale = context.getResources().getDisplayMetrics().density;
    LinearLayout llayout = new LinearLayout(context);
    llayout.setId(1);
    int padding_10 = (int)(10 * scale + 0.5f);
    int padding_5 = (int)(5 * scale + 0.5f);
    llayout.setPadding(padding_10, padding_10, padding_10, 0);
    llayout.setGravity(Gravity.CENTER_HORIZONTAL);
    LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
    llayout.setLayoutParams(params);
    Button button = new Button(context);
    button.setId(2);
    button.setTextColor(Color.WHITE);
    button.setTypeface(null, Typeface.BOLD);
    button.setTextSize(TypedValue.COMPLEX_UNIT_SP, 20);
    int padding_15 = (int)(15 * scale + 0.5f);
    button.setPadding(padding_15, padding_15, padding_15, padding_15);
    button.setBackgroundResource(R.drawable.custom_btn);
    button.setGravity(Gravity.CENTER_HORIZONTAL);
    button.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
    llayout.addView(button);
    return llayout;
}

Answer 1

FrameLayout is designed to only show one parent view in it. Replace it with a LinearLayout like below and test it.

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/dragTopView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

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

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textStyle="bold"
            android:textSize="20sp" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center">

            <EditText
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:ems="10"
                android:padding="10dip" />

            <ImageView
                android:id="@+id/quick_icon"
                android:layout_width="35dip"
                android:layout_height="35dip"
                android:scaleType="centerCrop" />
        </LinearLayout>
    </LinearLayout>

    <LinearLayout
        android:id="@+id/contacts"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <ListView
            android:id="@+id/contactsListView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:dividerHeight="1dip" >
        </ListView>
    </LinearLayout>
</LinearLayout>

If you want to stack your views up, replace your LinearLayout with RelativeLayout and edit the height and width of the views you want. RelativeLayout enables you to stack views.

Answer 2

does not stack it up, it just shows 1 view.. in your case it is the LinearLayout. 不会将其堆叠起来，它仅显示1个视图。在您的情况下，它是LinearLayout。

without further declarations stack it up. 会将其堆叠起来。 Just match the Relative layout's height and width.