Android 超级好用的均分布局AverageLayout

开篇

  很久没有更新博客了。本篇给同学们分享一个简单的超级好用的均分布局，提升你的开发效率。

场景

  在日常开发中会经常用到均分布局，而我们通常的做法是用LinearLayout和android:layout_weight配合完成。但是有时候，child并不需要占用1个比重，这时候为了满足android:layout_weight居中，不得不给child再包一层父类。而此控件就是为了解决这个问题因运而生！当然，通过ConstraintLayout经过复杂的约束也能达到这个效果，只是AverageLayout比ConstraintLayout更简洁方便。

效果截屏

立即体验

扫描以下二维码下载体验App(从0.2.3版本开始，体验App内嵌版本更新检测功能)：

JSCKit库传送门：https://github.com/JustinRoom/JSCKit

简析源码

AverageLayout.java

public class AverageLayout extends ViewGroup implements IViewAttrDelegate{}

• 1、测量

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int childCount = getChildCount();
        if (childCount > 0){
            measureChildren(widthMeasureSpec, heightMeasureSpec);
            LayoutParams params = getLayoutParams();
            int width = 0;
            int height = 0;
            switch (orientation){
                case HORIZONTAL:
                    width = getPaddingLeft() + getPaddingRight();
                    for (int i = 0; i < childCount; i++) {
                        View child = getChildAt(i);
                        width += child.getMeasuredWidth();
                        height = Math.max(height, child.getMeasuredHeight());
                    }
                    height = height + getPaddingTop() + getPaddingBottom();
                    if (params.width == LayoutParams.WRAP_CONTENT){
                        widthMeasureSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY);
                    }
                    if (params.height == LayoutParams.WRAP_CONTENT){
                        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
                    }
                    break;
                case VERTICAL:
                    height = getPaddingTop() + getPaddingBottom();
                    for (int i = 0; i < childCount; i++) {
                        View child = getChildAt(i);
                        height += child.getMeasuredHeight();
                        width = Math.max(width, child.getMeasuredWidth());
                    }
                    width = width + getPaddingLeft() + getPaddingRight();
                    if (params.height == LayoutParams.WRAP_CONTENT){
                        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
                    }
                    if (params.width == LayoutParams.WRAP_CONTENT){
                        widthMeasureSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY);
                    }
                    break;
            }
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

• 2、放置

protected void onLayout(boolean changed, int l, int t, int r, int b)

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int childCount = getChildCount();
        int width = getMeasuredWidth();
        int height = getMeasuredHeight();
        int left = 0;
        int top = 0;
        if (childCount > 0){
            switch (orientation){
                case HORIZONTAL:
                    int avWidth = (width - getPaddingLeft() - getPaddingRight()) / childCount;
                    for (int i = 0; i < childCount; i++) {
                        View child = getChildAt(i);
                        left = getPaddingLeft() + i * avWidth + (avWidth - child.getMeasuredWidth()) / 2;
                        top = (height - child.getMeasuredHeight()) / 2;
                        child.layout(left, top, left + child.getMeasuredWidth(), top + child.getMeasuredHeight());
                    }
                    break;
                case VERTICAL:
                    int avHeight = (height - getPaddingTop() - getPaddingBottom()) / childCount;
                    for (int i = 0; i < childCount; i++) {
                        View child = getChildAt(i);
                        left = (width - child.getMeasuredWidth()) / 2;
                        top = getPaddingTop() + i * avHeight + (avHeight - child.getMeasuredHeight()) / 2;
                        child.layout(left, top, left + child.getMeasuredWidth(), top + child.getMeasuredHeight());
                    }
                    break;
            }
        }
    }

使用示例

    <jsc.kit.component.widget.AverageLayout
        android:id="@+id/average_layout"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="center_horizontal"
        android:background="#f2f"
        app:orientation="horizontal">

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/main_mid_show_left_camera" />

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/main_mid_show_left_share" />

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/main_mid_show_left_yx" />

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/main_icon_create" />

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/main_mid_show_left_fullscreen" />

    </jsc.kit.component.widget.AverageLayout>

其他的不多说了，请自行安装体验app体验，用过才会知道它的好👌。
😊童鞋们，如果你们觉得不错的话给我点个💗吧，谢谢！！！

篇尾

  Wechat:eoy9527。

在人生的道路上，当你的希望一个个落空的时候，你也要坚定，要沉着。 —— 朗费罗