下面是流式布局的简单实用，先看效果图：
下面是针对流式布局 FlowLayout 的内容：
- 工具类 FlowLayout
- MainActivity 中使用
GitHub 下载地址：https://github.com/wuqingsen/FlowLayout
CSDN 下载地址：https://download.csdn.net/download/wuqingsen1/10808706
1.工具类 FlowLayout
不多说，代码虽多，但复制既可用：
import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import java.util.ArrayList;
import java.util.List;
/**
* 流式布局
*/
public class FlowLayout extends ViewGroup {
public FlowLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public FlowLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public FlowLayout(Context context) {
this(context, null);
}
@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);
// 如果是warp_content情况下，记录宽和高
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++) {
// 通过索引拿到每一个子view
View child = getChildAt(i);
// 测量子View的宽和高,系统提供的measureChild
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 判断 当前的宽度大于 开辟新行
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);
}
// 特殊情况,最后一个控件
if (i == cCount - 1) {
width = Math.max(lineWidth, width);
height += lineHeight;
}
}
setMeasuredDimension(
modeWidth == MeasureSpec.EXACTLY ? sizeWidth : width + getPaddingLeft() + getPaddingRight(),
modeHeight == MeasureSpec.EXACTLY ? sizeHeight : height + getPaddingTop() + getPaddingBottom()//
);
}
/**
* 存储所有的View
*/
private List<List<View>> mAllViews = new ArrayList<List<View>>();
/**
* 每一行的高度
*/
private List<Integer> mLineHeight = new ArrayList<Integer>();
@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;
// 存放每一行的子view
List<View> lineViews = new ArrayList<View>();
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<View>();
}
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);
for (int j = 0; j < lineViews.size(); j++) {
View child = lineViews.get(j);
// 判断child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();
// 为子View进行布局
child.layout(lc, tc, rc, bc);
left += child.getMeasuredWidth() + lp.leftMargin
+ lp.rightMargin;
}
left = getPaddingLeft();
top += lineHeight;
}
}
/**
* 与当前ViewGroup对应的LayoutParams
*/
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new MarginLayoutParams(getContext(), attrs);
}
}2. MainActivity 中使用
工具类写好，就开始使用了，首先在布局文件 activity_main 中添加流式布局：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.example.qd.flowlayout.FlowLayout
android:id="@+id/flowLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>然后在 MainActivity 中添加代码：
public class MainActivity extends AppCompatActivity {
private FlowLayout flowLayout;
private List<String> list;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
flowLayout = findViewById(R.id.flowLayout);
//添加数据
list = new ArrayList<>();
list.add("哈哈哈");
list.add("哈你妹");
list.add("妹妹好啊，在干嘛");
list.add("一起来玩");
list.add("不了");
list.add("那好吧");
list.add("明天去哪里，去日本，去浪漫的土耳其");
list.add("你去吧");
list.add("哦");
//设置流式布局
setFlowLayout();
}
private void setFlowLayout() {
flowLayout.removeAllViews();
for (int i = 0; i < list.size(); i++) {
LayoutInflater mInflater = LayoutInflater.from(this);
TextView tv = (TextView) mInflater.inflate(
R.layout.flow_layout, flowLayout, false);
tv.setText(list.get(i));
//点击事件
final int position = i;
tv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(MainActivity.this, list.get(position), Toast.LENGTH_SHORT).show();
}
});
flowLayout.addView(tv);//添加到父View
}
}
}这样就 OK 了，最后是布局 flow_layout 的代码：
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="3dp"
android:gravity="center"
android:paddingRight="8dp"
android:paddingLeft="8dp"
android:paddingTop="2dp"
android:paddingBottom="2dp"
android:text="HelloWorld"
android:textSize="18dp"
android:textColor="#FFFFFF"
android:background="@drawable/shape_blue"/>
流式布局到这里就可以实现了。