【Android-view】listView 每个item里动态添加不定量的控件，Android 自动换行2014-04-10 07:46:15cnblogs.com-helloworld.MR-zz-点击数:744
问题描述： 开发过程中，遇到了在listview里面的每个item都有可能显示图片，并且需要显示的图片的数量不确定，需要自动换行。 如图：第一行显示三张图片，第二行显示四张图片。数量0---正无穷（内存支持的情况下）
解决办法： 最初就是直接从网上找Android自动换行的控件，再此感谢eoe论坛里**dahege **分享的源码。 dahege eoe论坛原文地址：http://www./forum.php?mod=viewthread&tid=195276 但是我直接拿来用的时候出现了个问题，就是当有四张图片的时候只显示三行。 具体解决办法如下： a.修改values下attrs.xml文件 增加一个每行显示多少列的属性，类似gridview 1 <resources> 2 <declare-styleable name="FlowLayout"> 3 <attr name="horizontalSpacing" format="dimension" /> 4 <attr name="verticalSpacing" format="dimension" /> 5 <attr name="numColumns" format="integer" /><!--这个属性为新加的--> 6 </declare-styleable> 7 <declare-styleable name="FlowLayout_LayoutParams"> 8 <attr name="layout_breakLine" format="boolean" /> 9 <attr name="layout_horizontalSpacing" format="dimension" />10 </declare-styleable>11 </resources>
b.修改FlowLayout.java 源文件 1.在构造方法里得到用户在cml文件里设置的numColumns public FlowLayout(Context context, AttributeSet attrs) { super(context, attrs); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.FlowLayout); try { mHorizontalSpacing = a.getDimensionPixelSize(R.styleable.FlowLayout_horizontalSpacing, 0); mVerticalSpacing = a.getDimensionPixelSize(R.styleable.FlowLayout_verticalSpacing, 0); numColumns = a.getInt(R.styleable.FlowLayout_numColumns, 3);//得到用户在布局文件中设置的没行显示的列数 } finally { a.recycle(); } mPaint = new Paint(); mPaint.setAntiAlias(true); mPaint.setColor(0xffff0000); mPaint.setStrokeWidth(2.0f); }
2.修改onMeasure方法，由于对这块还不太了解，所以只是简单的改了一下，测试之后效果是实现了，暂未发现其他问题。应该还有更好的解决方案，希望有人指正。 1 @Override 2 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 3 int widthSize = MeasureSpec.getSize(widthMeasureSpec) - getPaddingRight(); 4 int widthMode = MeasureSpec.getMode(widthMeasureSpec); 5 boolean growHeight = widthMode != MeasureSpec.UNSPECIFIED; 6 7 int width = 0; 8 int height = getPaddingTop(); 9 10 int currentWidth = getPaddingLeft(); 11 int currentHeight = 0; 12 13 boolean breakLine = false;14 boolean newLine = false;15 int spacing = 0;16 17 final int count = getChildCount();18 for (int i = 0; i < count; i++) {19 View child = getChildAt(i);20 measureChild(child, widthMeasureSpec, heightMeasureSpec);21 22 LayoutParams lp = (LayoutParams) child.getLayoutParams();23 spacing = mHorizontalSpacing;24 if (lp.horizontalSpacing >= 0) {25 spacing = lp.horizontalSpacing;26 }27 28 if (growHeight && (i == numColumns||breakLine || currentWidth + child.getMeasuredWidth() > widthSize)) {29 // newLine = true;30 31 height += currentHeight + mVerticalSpacing;32 width = Math.max(width, currentWidth - spacing);33 34 currentHeight = 0;35 currentWidth = getPaddingLeft();36 37 }38 // else {39 // newLine = false;40 // }41 if (i>numColumns&&i%numColumns==0) {//主要修改的是这个判断语句，原版的判断语句是29,38,39,40行的被隐掉的。我自己用原版的判断语句有问题，42 newLine = false;43 }44 45 lp.x = currentWidth;46 lp.y = height;47 48 currentWidth += child.getMeasuredWidth() + spacing;49 currentHeight = Math.max(currentHeight, child.getMeasuredHeight());50 51 breakLine = lp.breakLine;52 }53 54 if (!newLine) {55 height += currentHeight;56 width = Math.max(width, currentWidth - spacing);57 }58 59 width += getPaddingRight();60 height += getPaddingBottom();61 62 setMeasuredDimension(resolveSize(width, widthMeasureSpec),63 resolveSize(height, heightMeasureSpec));64 }
至此，就修改完毕了。 具体使用办法如下。 a.在listview的item布局文件中使用framelayout自定义控件 1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas./apk/res/android" 3 xmlns:f="http://schemas./apk/res/你的androidmanifest.xml文件中的package属性值" 4 android:layout_width="fill_parent" 5 android:layout_height="wrap_content" 6 > 7 8 9 <com.xingyunhudong.view.FlowLayout10 android:id="@+id/flowlaytou"11 android:layout_width="fill_parent"12 android:layout_height="wrap_content"13 android:layout_marginTop="8dp" f:numColumns="3"<!--也可以不指定，如果不指定，在FrameLayout的构造函数里，默认取值为3列-->14 >15 </com.xingyunhudong.view.FlowLayout>16 17 18 19 </LinearLayout>
b.在adapter中设值 public class XXXAdapterextends BaseAdapter { private LayoutInflater inflater; private List<XXX> xxxList; private Context context; private ViewGroup.LayoutParams paramsImg, paramsVideo; private int sw; public HuaTiAdapter(Context context, List<xxx> xxxList) { this.xxxList = xxxList; this.context = context; inflater = (LayoutInflater) context .getSystemService(Context.LAYOUT_INFLATER_SERVICE); sw = CommonUtils.getScreenWidth((Activity) context); int w = context.getResources().getDimensionPixelSize( R.dimen.xxx_img_total_width); sw = sw - w; paramsImg = new ViewGroup.LayoutParams(sw / 3, sw / 3); paramsVideo = new ViewGroup.LayoutParams(sw, 0);//为了图片适配 } @Override public int getCount() { // TODO Auto-generated method stub return xxxList.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub return xxxList.get(position); } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } class ViewHolder { FlowLayout ll; int flag; } @Override public View getView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub ViewHolder holder = null; xxxBean huati = xxxList.get(position); if (convertView == null || ((ViewHolder) convertView.getTag()).flag != position) {//第一个判断是优化listview加载速度及内存消耗，第二个判断是为了防止图片错位 holder = new ViewHolder(); holder.flag = position; convertView = inflater.inflate(R.layout.xxx_item_layout, null); holder.ll = (FlowLayout) convertView.findViewById(R.id.flowlaytou); ImageBean video = xxx.getVideoImg(); if (video != null && video.getUrl() != null && !"".equals(video.getUrl().trim())) { paramsVideo.height = video.getHeight() * sw / video.getWidth(); addVideoView(holder.ll, video.getUrl(), paramsVideo, inflater); } List<ImageBean> imgList = huati.getImgList(); if (imgList != null && imgList.size() > 0) { for (int i = 0; i < imgList.size(); i++) { addImageView(holder.ll, imgList.get(i).getUrl(), paramsImg, inflater, imgList, i); } } convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } return convertView; } private void addVideoView(FlowLayout ll, final String url, LayoutParams params, LayoutInflater inflater) { ImageView v = (ImageView) inflater.inflate( R.layout.yyy_image_layout, null);//这个layout里面就只有一个imageview空间，特别简单 v.setLayoutParams(params); ImageUtil.display(url, v); v.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub //这里的点击事件也完全没有问题，不会错位，不会点击失效 } }); ll.addView(v); } private void addImageView(FlowLayout ll, String url, LayoutParams params, LayoutInflater inflater) { // TODO Auto-generated method stub ImageView v = (ImageView) inflater.inflate( R.layout.weixiu_image_layout, null); v.setLayoutParams(params); ImageUtil.display(url, v); v.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub//这里的点击事件也完全没有问题，不会错位，不会点击失效 } }); ll.addView(v); } }
至此，就就结束了，希望可以帮到一部分人。
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