Android自定义流式布局/自动换行布局实例

最近，Google开源了一个流式排版库“FlexboxLayout”，功能强大，支持多种排版方式，如各种方向的自动换行等，具体资料各位可搜索学习^_^。

由于我的项目中，只需要从左到右S型的自动换行，需求效果图如下：

使用FlexboxLayout这个框架未免显得有些臃肿，所以自己动手写了一个流式ViewGroup。

安卓中自定义ViewGroup的步骤是：

1. 新建一个类，继承ViewGroup

2. 重写构造方法

3. 重写onMeasure、onLayout方法

onMeasuer方法里一般写测量子View宽高、确定此控件宽高的代码；onLayout方法则是确定子View如何摆放（排版）。

代码如下：

import android.content.Context; import android.util.AttributeSet; import android.view.View; import android.view.ViewGroup; public class FlexBoxLayout extends ViewGroup { private int mScreenWidth; private int horizontalSpace, verticalSpace; private float mDensity;//设备密度，用于将dp转为px public FlexBoxLayout(Context context) { this(context, null); } public FlexBoxLayout(Context context, AttributeSet attrs) { super(context, attrs); //获取屏幕宽高、设备密度 mScreenWidth = context.getResources().getDisplayMetrics().widthPixels; mDensity = context.getResources().getDisplayMetrics().density; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); //确定此容器的宽高 int widthMode = MeasureSpec.getMode(widthMeasureSpec); int widthSize = MeasureSpec.getSize(widthMeasureSpec); int heightMode = MeasureSpec.getMode(heightMeasureSpec); int heightSize = MeasureSpec.getSize(heightMeasureSpec); //测量子View的宽高 int childCount = getChildCount(); View child = null; //子view摆放的起始位置 int left = getPaddingLeft(); //一行view中将最大的高度存于此变量，用于子view进行换行时高度的计算 int maxHeightInLine = 0; //存储所有行的高度相加，用于确定此容器的高度 int allHeight = 0; for (int i = 0; i < childCount; i++) {child = getChildAt(i);//测量子View宽高measureChild(child, widthMeasureSpec, heightMeasureSpec);//两两对比，取得一行中最大的高度if (child.getMeasuredHeight() + child.getPaddingTop() + child.getPaddingBottom() > maxHeightInLine) { maxHeightInLine = child.getMeasuredHeight() + child.getPaddingTop() + child.getPaddingBottom();}left += child.getMeasuredWidth() + dip2px(horizontalSpace) + child.getPaddingLeft() + child.getPaddingRight();if (left >= widthSize - getPaddingRight() - getPaddingLeft()) {//换行 left = getPaddingLeft(); //累积行的总高度 allHeight += maxHeightInLine + dip2px(verticalSpace); //因为换行了，所以每行的最大高度置0 maxHeightInLine = 0;} } //再加上最后一行的高度,因为之前的高度累积条件是换行 //最后一行没有换行操作，所以高度应该再加上 allHeight += maxHeightInLine; if (widthMode != MeasureSpec.EXACTLY) {widthSize = mScreenWidth;//如果没有指定宽，则默认为屏幕宽 } if (heightMode != MeasureSpec.EXACTLY) {//如果没有指定高度heightSize = allHeight + getPaddingBottom() + getPaddingTop(); } setMeasuredDimension(widthSize, heightSize); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { if (changed) { //摆放子view View child = null; //初始子view摆放的左上位置 int left = getPaddingLeft(); int top = getPaddingTop(); //一行view中将最大的高度存于此变量，用于子view进行换行时高度的计算 int maxHeightInLine = 0; for (int i = 0, len = getChildCount(); i < len; i++) { child = getChildAt(i); //从第二个子view开始算起 //因为第一个子view默认从头开始摆放 if (i > 0) { //两两对比，取得一行中最大的高度 if (getChildAt(i - 1).getMeasuredHeight() > maxHeightInLine) { maxHeightInLine = getChildAt(i - 1).getMeasuredHeight(); } //当前子view的起始left为 上一个子view的宽度+水平间距 left += getChildAt(i - 1).getMeasuredWidth() + dip2px(horizontalSpace); if (left + child.getMeasuredWidth() >= getWidth() - getPaddingRight() - getPaddingLeft()) {//这一行所有子view相加的宽度大于容器的宽度，需要换行 //换行的首个子view，起始left应该为0+容器的paddingLeft left = getPaddingLeft(); //top的位置为上一行中拥有最大高度的某个View的高度+垂直间距 top += maxHeightInLine + dip2px(verticalSpace); //将上一行View的最大高度置0 maxHeightInLine = 0; } } //摆放子view child.layout(left, top, left + child.getMeasuredWidth(), top + child.getMeasuredHeight()); } } } /** * dp转为px * * @param dpValue * @return */ private int dip2px(float dpValue) { return (int) (dpValue * mDensity + 0.5f); } /** * 设置子view间的水平间距 单位dp * * @param horizontalSpace */ public void setHorizontalSpace(int horizontalSpace) { this.horizontalSpace = horizontalSpace; } /** * 设置子view间的垂直间距 单位dp * * @param verticalSpace */ public void setVerticalSpace(int verticalSpace) { this.verticalSpace = verticalSpace; } }

使用如下：

xml文件：

<com.zengd.FlexBoxLayout android: android:layout_width='match_parent' android:layout_height='match_parent'> <!--这里写子View，也可代码动态添加--> …… </com.zengd.FlexBoxLayout>

Activity里的代码：

FlexBoxLayout flexBoxLayout = (FlexBoxLayout) findViewById(R.id.flex_box_layout); flexBoxLayout.setHorizontalSpace(10);//不设置默认为0 flexBoxLayout.setVerticalSpace(10);//不设置默认为0

运行效果如图：

本项目Demo地址:

https://github.com/zengd0/FlexBoxLayout

补充知识：Android 流式布局(修改版) 当达到两行，隐藏多余的

我就废话不多说了，还是直接看代码吧！

public class SearchLayout extends LinearLayout { private final int mParentWidth; private float textSize; private boolean textColor; private boolean background; private boolean isHide = true; public void setHide(boolean hide) { isHide = hide; } public SearchLayout(Context context, AttributeSet attrs) { super(context, attrs); //获取屏幕的宽度 DisplayMetrics metrics = context.getResources().getDisplayMetrics(); mParentWidth = metrics.widthPixels - dip2px(16f); //自定义属性 TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.SearchLayout); background = array.getBoolean(R.styleable.SearchLayout_Sear_background,false); textColor = array.getBoolean(R.styleable.SearchLayout_Sear_textColor, false); textSize = array.getDimension(R.styleable.SearchLayout_Sear_textSize, 0); //方向为纵向 setOrientation(VERTICAL); } //移除子控件 public void removeView() { removeAllViews(); } //流式布局 public void setData(List<String> data) { if (data.isEmpty()){ return; } //获取一个子布局 LinearLayout linearLayout = getLinearLayout(); for (int i = 0; i < data.size(); i++) { //标题 final String name = data.get(i); //已存在的宽度 int numBar = 0; //子控件的个数 int count = linearLayout.getChildCount(); for (int j = 0; j < count; j++) {//一个一个获取ThemeTextView textView = (ThemeTextView) linearLayout.getChildAt(j);//获取左外边距LayoutParams params = (LayoutParams) textView.getLayoutParams();int leftWidth = params.leftMargin;int rightWidth = params.rightMargin;//获取宽高textView.measure(getMeasuredWidth(), getMeasuredHeight());//计算已存在的宽度numBar += textView.getMeasuredWidth()+leftWidth+rightWidth; } //获取一个子控件 ThemeTextView text = getText(); //给每一个控件设置点击事件 text.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View view) { if (onItemTitleClickListener != null){ onItemTitleClickListener.onItemTitle(name); }} }); //赋值 text.setText(name); //获取宽高 text.measure(getMeasuredWidth(), getMeasuredHeight()); //当前控件的宽度 int textWidth = text.getMeasuredWidth() + text.getPaddingLeft() + text.getPaddingRight(); //判断是否超过屏幕 if (isHide && getChildCount() == 2){ImageView imageView = getMore(false);LayoutParams layoutParams = (LayoutParams) imageView.getLayoutParams();int leftM = layoutParams.leftMargin;int rightM = layoutParams.rightMargin;imageView.measure(getMeasuredWidth(), getMeasuredHeight());int width = imageView.getMeasuredWidth() + imageView.getPaddingLeft() + imageView.getPaddingRight();int imageWidth = leftM + rightM + width;if (numBar + textWidth + imageWidth >= mParentWidth){ if (numBar + textWidth + imageWidth > mParentWidth){ imageView.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) {if (onMoreClickListener != null){ onMoreClickListener.onShowMore(isHide);} } }); linearLayout.addView(imageView); return; } else { imageView.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) {if (onMoreClickListener != null){ onMoreClickListener.onShowMore(isHide);} } }); linearLayout.addView(text); linearLayout.addView(imageView); return; }}else { if (i + 1 <= data.size()-1) { String title = data.get(i + 1); ThemeTextView themeTextView = getText(); themeTextView.setText(title); themeTextView.measure(getMeasuredWidth(),getMeasuredHeight()); int themeTextViewWidth = themeTextView.getMeasuredWidth() + themeTextView.getPaddingLeft() + themeTextView.getPaddingRight(); if (mParentWidth >= numBar + textWidth + imageWidth + themeTextViewWidth ){ linearLayout.addView(text); continue; }else { imageView.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) { if (onMoreClickListener != null){ onMoreClickListener.onShowMore(isHide); }} }); linearLayout.addView(text); linearLayout.addView(imageView); return; } }} } if (i == data.size() - 1 && (getChildCount() >= 3 || (mParentWidth < numBar + textWidth) && getChildCount() == 2)){ImageView imageView = getMore(true);LayoutParams layoutParams = (LayoutParams) imageView.getLayoutParams();int leftM = layoutParams.leftMargin;int rightM = layoutParams.rightMargin;imageView.measure(getMeasuredWidth(), getMeasuredHeight());int width = imageView.getMeasuredWidth() + imageView.getPaddingLeft() + imageView.getPaddingRight();int imageWidth = leftM + rightM + width;imageView.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { if (onMoreClickListener != null){ onMoreClickListener.onShowMore(isHide); } }});if (mParentWidth >= numBar + textWidth + imageWidth){ linearLayout.addView(text); linearLayout.addView(imageView);}else { if (mParentWidth >= numBar + textWidth){ linearLayout.addView(text); linearLayout = getLinearLayout(); linearLayout.addView(imageView); }else { linearLayout = getLinearLayout(); linearLayout.addView(text); linearLayout.addView(imageView); }}return; } if (mParentWidth >= numBar + textWidth) {//没有，继续添加linearLayout.addView(text); } else {//否者，重新获取一个子布局，再添加linearLayout = getLinearLayout();linearLayout.addView(text); } } } public LinearLayout getLinearLayout() { //创建LinearLayout布局 LinearLayout linearLayout = new LinearLayout(getContext()); //设置宽高 LayoutParams params = new LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT); linearLayout.setLayoutParams(params); //添加到主布局中 this.addView(linearLayout); return linearLayout; } public ThemeTextView getText() { //创建TextView控件 //设置字体大小，颜色，内边距 ThemeTextView themeTextView = new ThemeTextView(getContext()); themeTextView.setTextSize(TypedValue.COMPLEX_UNIT_PX , textSize); themeTextView.setMaxEms(7); themeTextView.setLines(1); themeTextView.setEllipsize(TextUtils.TruncateAt.END); themeTextView.setPadding(dip2px(8), dip2px(4), dip2px(8), dip2px(4)); if (textColor){//可以根据自己的需求修改判断 themeTextView.setTextColor(ContextCompat.getColor(getContext(),R.color.day_text_color_thirdly)); }else { themeTextView.setTextColor(ContextCompat.getColor(getContext(),R.color.day_text_color_thirdly)); } if (background){ themeTextView.setBackgroundResource(R.drawable.border_search_background_day); } //设置宽高 LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); //外边距 params.setMargins(dip2px(8),dip2px(8),dip2px(8),dip2px(8)); themeTextView.setLayoutParams(params); return themeTextView; } public ImageView getMore(boolean isHide){ ImageView imageView = new ImageView(getContext()); if (background){ imageView.setBackgroundResource(R.drawable.border_search_background_day); } imageView.setImageResource(R.drawable.icon_more); if (isHide){ imageView.setRotation(180f); } imageView.setColorFilter(ContextCompat.getColor(getContext(),R.color.day_text_color_primary)); imageView.setPadding(dip2px(6), dip2px(6), dip2px(7), dip2px(7)); //设置宽高 LayoutParams params = new LayoutParams(ConfigSingleton.dip2px(27), ConfigSingleton.dip2px(27)); //外边距 params.setMargins(dip2px(8),dip2px(8),dip2px(8),dip2px(8)); imageView.setLayoutParams(params); return imageView; } public interface OnItemTitleClickListener{ void onItemTitle(String title); } public interface OnMoreClickListener{ void onShowMore(boolean ishide); } private OnItemTitleClickListener onItemTitleClickListener; private OnMoreClickListener onMoreClickListener; public void setOnItemTitleClickListener(OnItemTitleClickListener onItemTitleClickListener) { this.onItemTitleClickListener = onItemTitleClickListener; } public void setOnMoreClickListener(OnMoreClickListener onMoreClickListener) { this.onMoreClickListener = onMoreClickListener; }public int dip2px(float dipValue) {float scale = getContext().getResources().getDisplayMetrics().density;return (int) (dipValue * scale + 0.5f);}}

attrs文件:

<declare-styleable name='SearchLayout'> <attr name='Sear_textSize' format='dimension'/> <attr name='Sear_textColor' format='boolean'/> <attr name='Sear_background' format='boolean'/> </declare-styleable>

以上这篇Android自定义流式布局/自动换行布局实例就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持好吧啦网。