android中的BorderLayout？

Question

有没有办法在Android中实现工作可重用的边框布局？一个行为就像swing的BorderLayout：最大化中间并将其余部分缩小到最小尺寸？

Answer 1

试试这个，你会得到与Swings BorderLayout相同的行为（结果如图所示）：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

<TextView
    android:id="@+id/north"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:background="@android:color/holo_orange_light"
    android:gravity="center_horizontal"
    android:text="North"
    android:textAppearance="@android:style/TextAppearance.Large" />

<TextView
    android:id="@+id/south"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:background="@android:color/holo_blue_light"
    android:gravity="center_horizontal"
    android:text="South"
    android:textAppearance="@android:style/TextAppearance.Large" />

<TextView
    android:id="@+id/west"
    android:layout_width="wrap_content"
    android:layout_height="fill_parent"
    android:layout_above="@id/south"
    android:layout_alignParentLeft="true"
    android:layout_below="@id/north"
    android:background="@android:color/holo_red_light"
    android:gravity="center_vertical"
    android:text="West"
    android:textAppearance="@android:style/TextAppearance.Large" />

<TextView
    android:id="@+id/east"
    android:layout_width="wrap_content"
    android:layout_height="fill_parent"
    android:layout_above="@id/south"
    android:layout_alignParentRight="true"
    android:layout_below="@id/north"
    android:background="@android:color/holo_purple"
    android:gravity="center_vertical"
    android:text="East"
    android:textAppearance="@android:style/TextAppearance.Large" />

<TextView
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_above="@id/south"
    android:layout_below="@id/north"
    android:layout_toLeftOf="@id/east"
    android:layout_toRightOf="@id/west"
    android:background="@android:color/holo_green_light"
    android:gravity="center"
    android:text="Center"
    android:textAppearance="@android:style/TextAppearance.Large" />

Answer 2

您可以使用RelativeLayout和android:layout_weight属性来获得相同的效果。

Answer 3

我不想使用XML布局文件，并且在代码中使用RelativeLayout很麻烦。因此，我实现了自己的BorderLayout类：

public class BorderLayout extends ViewGroup {

    private View left;
    private View top;
    private View right;
    private View bottom;
    private View center;

    public BorderLayout(Context context) {
        super(context);
    }

    public void setLeft(View left) {
        if (this.left != null)
            removeView(this.left);
        this.left = left;
        if (this.left != null)
            addView(this.left);
    }

    public void setTop(View top) {
        if (this.top != null)
            removeView(this.top);
        this.top = top;
        if (this.top != null)
            addView(this.top);
    }

    public void setRight(View right) {
        if (this.right != null)
            removeView(this.right);
        this.right = right;
        if (this.right != null)
            addView(this.right);
    }

    public void setBottom(View bottom) {
        if (this.bottom != null)
            removeView(this.bottom);
        this.bottom = bottom;
        if (this.bottom != null)
            addView(this.bottom);
    }

    public void setCenter(View center) {
        if (this.center != null)
            removeView(this.center);
        this.center = center;
        if (this.center != null)
            addView(this.center);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int topWidth = 0;
        int topHeight = 0;
        if (top != null) {
            top.measure(widthMeasureSpec, MeasureSpec.UNSPECIFIED);
            topWidth = top.getMeasuredWidth();
            topHeight = top.getMeasuredHeight();
        }
        int bottomWidth = 0;
        int bottomHeight = 0;
        if (bottom != null) {
            bottom.measure(widthMeasureSpec, MeasureSpec.UNSPECIFIED);
            bottomWidth = bottom.getMeasuredWidth();
            bottomHeight = bottom.getMeasuredHeight();
        }
        int remainingHeightSpec = GuiUtil.subtractFromMeasureSpec(heightMeasureSpec, topHeight + bottomHeight);
        int leftWidth = 0;
        int leftHeight = 0;
        if (left != null) {
            left.measure(MeasureSpec.UNSPECIFIED, remainingHeightSpec);
            leftWidth = left.getMeasuredWidth();
            leftHeight = left.getMeasuredHeight();
        }
        int rightWidth = 0;
        int rightHeight = 0;
        if (right != null) {
            right.measure(MeasureSpec.UNSPECIFIED, remainingHeightSpec);
            rightWidth = right.getMeasuredWidth();
            rightHeight = right.getMeasuredHeight();
        }
        int remainingWidthSpec = GuiUtil.subtractFromMeasureSpec(widthMeasureSpec, leftWidth + rightWidth);
        int centerWidth = 0;
        int centerHeight = 0;
        if (center != null) {
            center.measure(remainingWidthSpec, remainingHeightSpec);
            centerWidth = center.getMeasuredWidth();
            centerHeight = center.getMeasuredHeight();
        }
        int width = Util.max(topWidth, leftWidth + centerWidth + rightWidth, bottomWidth);
        int height = topHeight + Util.max(leftHeight, centerHeight, rightHeight) + bottomHeight;
        setMeasuredDimension(GuiUtil.getDefaultSize(width, widthMeasureSpec), GuiUtil.getDefaultSize(height, heightMeasureSpec));
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int w = r - l;
        int h = b - t;
        int topHeight = 0;
        if (top != null) {
            topHeight = top.getMeasuredHeight();
            top.layout(0, 0, w, topHeight);
        }
        int bottomHeight = 0;
        if (bottom != null) {
            bottomHeight = bottom.getMeasuredHeight();
            bottom.layout(0, h - bottomHeight, w, h);
        }
        int leftWidth = 0;
        if (left != null) {
            leftWidth = left.getMeasuredWidth();
            left.layout(0, topHeight, leftWidth, h - bottomHeight);
        }
        int rightWidth = 0;
        if (right != null) {
            rightWidth = right.getMeasuredWidth();
            right.layout(w - rightWidth, topHeight, w, h - bottomHeight);
        }
        if (center != null)
            center.layout(leftWidth, topHeight, w - rightWidth, h - bottomHeight);
    }

}