自动换行容器的自定义FlowContainer

固定容器的宽高信息，往容器内添加子view，子view按行排列，当宽度快超出容器宽度时，换行继续排列

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

public class FlowContainer extends ViewGroup{
private final static int VIEW_MARGIN = 2;//子view自己的间距
private int clientWidth;
public FlowContainer(Context context) {
super(context);
}
public FlowContainer(Context context, AttributeSet attrs) {
super(context, attrs);
}
public FlowContainer(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
//获取整个flowContainer的宽度
clientWidth = MeasureSpec.getSize(widthMeasureSpec);
//从第一行开始测量
int row = 0;
int lengthX = 0;
int lengthY = 0;
//循环测量子view，得到子view最终占flowContainer宽高
for(int index = 0; index < getChildCount(); index++){
View child = getChildAt(index);
if(child.getVisibility() == View.GONE){
continue;
}
//子view的宽高不限制，获取子view自己给定的宽高信息
child.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
int width = child.getMeasuredWidth();
int height = child.getMeasuredHeight();

lengthX += width + VIEW_MARGIN;
lengthY = row * (height + VIEW_MARGIN) + VIEW_MARGIN + height;
//第一行 所有子view的宽度>父容器宽度  准备换行
if((lengthX + VIEW_MARGIN) > clientWidth){
//下一行的 宽度开始计算
lengthX = width + VIEW_MARGIN;
row++;
//下一行后 总宽度
lengthY = row * (height +VIEW_MARGIN) + VIEW_MARGIN + height;
}
}
lengthY = lengthY + VIEW_MARGIN;
//设置容器所需的宽度和高度（宽度为父宽，高为所有子view算出来的）
setMeasuredDimension(clientWidth, lengthY);
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
int row = 0;
top = VIEW_MARGIN;
int lengthX = left;
int lengthY = 0;
for(int i = 0; i < getChildCount(); i++){
View child = this.getChildAt(i);
if(child.getVisibility() == View.GONE){
continue;
}
int width = child.getMeasuredWidth();
int height = child.getMeasuredHeight();

lengthX += width + VIEW_MARGIN;
lengthY = row * (height + VIEW_MARGIN) + VIEW_MARGIN + height + top;
if((lengthX + VIEW_MARGIN) > right){
lengthX = width + VIEW_MARGIN + left;
row++;
lengthY = row * (height + VIEW_MARGIN) +VIEW_MARGIN + height + top;
}
child.layout(lengthX - width, lengthY - height, lengthX, lengthY);
}
}
}

布局文件如下：这里的容器高度随子view的多少撑高，但是高度超出屏幕后无法滑动，所以外部套一个scrollView来滑动

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.whc.view.FlowContainer
android:id="@+id/flow_container"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</com.whc.view.FlowContainer>
</ScrollView>

activity中就随便放置多个textView来展示效果吧

import java.util.ArrayList;
import java.util.List;

import com.whc.view.FlowContainer;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class FlowActivity extends Activity {

private FlowContainer flowContainer;
private List<String> list;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.flow_activity);
flowContainer = (FlowContainer) findViewById(R.id.flow_container);

initData();
initView();
}

private void initView() {
for(int i = 0; i<list.size(); i++){
TextView tv = new TextView(this);
tv.setText(list.get(i));
flowContainer.addView(tv);
}
}

private void initData() {
list = new ArrayList<String>();
for(int i = 0; i < 500; i++){
list.add("第"+i+"几个view");
}
}
}

这样容器内的子textView就会横向排列，当快超出容器宽度时，换行继续