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package com.example.flowlayout.view; import java.util.ArrayList; import java.util.List; import android.content.Context; import android.util.AttributeSet; import android.util.Log; import android.view.View; import android.view.ViewGroup; //ViewGroup对应LayoutParams public class FlowLayout extends ViewGroup { public FlowLayout(Context context) { super(context); } public FlowLayout(Context context, AttributeSet attrs) { super(context, attrs); } public FlowLayout(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int sizeWidth = MeasureSpec.getSize(widthMeasureSpec); int modeWidth = MeasureSpec.getMode(widthMeasureSpec); int sizeHeight = MeasureSpec.getSize(heightMeasureSpec); int modeHeight = MeasureSpec.getMode(heightMeasureSpec); // wrap_content int width = 0; int height = 0; // 记录每一行的宽度与高度 int lineWidth = 0; int lineHeight = 0; // 得到内部元素的个数 int cCount = getChildCount(); for (int i = 0; i < cCount; i++) { View child = getChildAt(i); // 测量子View的宽和高 measureChild(child, widthMeasureSpec, heightMeasureSpec); // 得到LayoutParams MarginLayoutParams lp = (MarginLayoutParams) child .getLayoutParams(); // 子View占据的宽度 int childWidth = child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin; // 子View占据的高度 int childHeight = child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin; // 换行 if (lineWidth + childWidth > sizeWidth - getPaddingLeft() - getPaddingRight()) { // 对比得到最大的宽度 width = Math.max(width, lineWidth); // 重置lineWidth lineWidth = childWidth; // 记录行高 height += lineHeight; lineHeight = childHeight; } else // 未换行 { // 叠加行宽 lineWidth += childWidth; // 得到当前行最大的高度 lineHeight = Math.max(lineHeight, childHeight); } // 最后一个控件 if (i == cCount - 1) { width = Math.max(lineWidth, width); height += lineHeight; } } Log.e("TAG", "sizeWidth = " + sizeWidth); Log.e("TAG", "sizeHeight = " + sizeHeight); setMeasuredDimension( // modeWidth == MeasureSpec.EXACTLY ? sizeWidth : width + getPaddingLeft() + getPaddingRight(), modeHeight == MeasureSpec.EXACTLY ? sizeHeight : height + getPaddingTop() + getPaddingBottom()// ); } /** * 存储所有的View,集合长度为三 */ private List<List> mAllViews = new ArrayList<List>(); /** * 每一行的高度 */ private List mLineHeight = new ArrayList(); @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { mAllViews.clear(); mLineHeight.clear(); // 当前ViewGroup的宽度 int width = getWidth(); int lineWidth = 0; int lineHeight = 0; List lineViews = new ArrayList(); int cCount = getChildCount(); for (int i = 0; i < cCount; i++) { View child = getChildAt(i); MarginLayoutParams lp = (MarginLayoutParams) child .getLayoutParams(); int childWidth = child.getMeasuredWidth(); int childHeight = child.getMeasuredHeight(); // 如果需要换行 if (childWidth + lineWidth + lp.leftMargin + lp.rightMargin > width - getPaddingLeft() - getPaddingRight()) { // 记录LineHeight mLineHeight.add(lineHeight); // 记录当前行的Views mAllViews.add(lineViews); // 重置我们的行宽和行高 lineWidth = 0; lineHeight = childHeight + lp.topMargin + lp.bottomMargin; // 重置我们的View集合 lineViews = new ArrayList(); } lineWidth += childWidth + lp.leftMargin + lp.rightMargin; lineHeight = Math.max(lineHeight, childHeight + lp.topMargin + lp.bottomMargin); lineViews.add(child); }// for end // 处理最后一行 mLineHeight.add(lineHeight); mAllViews.add(lineViews); // 设置子View的位置 int left = getPaddingLeft(); int top = getPaddingTop(); // 行数 int lineNum = mAllViews.size(); for (int i = 0; i < lineNum; i++) { // 当前行的所有的View lineViews = mAllViews.get(i); lineHeight = mLineHeight.get(i); // 遍历当前行所有的子view for (int j = 0; j < lineViews.size(); j++) { View child = lineViews.get(j); // 判断child的状态(子view的状态) if (child.getVisibility() == View.GONE) { continue; } MarginLayoutParams lp = (MarginLayoutParams) child .getLayoutParams(); int lc = left + lp.leftMargin; int tc = top + lp.topMargin; int rc = lc + child.getMeasuredWidth(); int bc = tc + child.getMeasuredHeight(); // 为每一个子View进行布局;layout() child.layout(lc, tc, rc, bc); // 为每个子view布局时,宽度是不一样的(宽度不断叠加) left += child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin; } // 第二行时,top需要累加,left需要清空。前一行已经遍历完了。 left = getPaddingLeft(); top += lineHeight; } } /** * 与当前ViewGroup对应的LayoutParams */ @Override public LayoutParams generateLayoutParams(AttributeSet attrs) { return new MarginLayoutParams(getContext(), attrs); } }
流式布局 自定义控件 特别热
原文地址:http://blog.csdn.net/chenrushui/article/details/51340005