自定义Android流布局实现推荐标签功能

第一步：自定义流布局

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);


// 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
*/
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;


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);
}


}

第二部：在布局中使用

<com.bjtxwy.efun.utils.cflayout    android:id="@+id/fl_activity_search"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:layout_marginTop="10dp"    android:layout_marginLeft="10dp"    android:layout_marginRight="10dp"    >

第三部：定义热标签

<?xml version="1.0" encoding="utf-8"?><TextView xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_margin="5dp"    android:background="@drawable/textview_bg" >//这个背景设置自己定义，可以不要</TextView>

第四部逻辑实现

package com.bjtxwy.efun.activity.search;import android.os.Bundle;import com.bjtxwy.efun.R;import com.bjtxwy.efun.base.BaseActivity;import com.bjtxwy.efun.utils.cflayout;import android.view.LayoutInflater;import android.widget.TextView;/** * Created by Administrator on 2015/12/9. */public class SearchActivity extends BaseActivity {    private String mNames[] = {            "welcome","android","TextView",            "apple","jamy","kobe bryant",            "jordan","layout","viewgroup",            "margin","padding","text",            "name","type","search","logcat"    };    private cflayout mFlowLayout;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_search);        mFlowLayout= (cflayout) findViewById(R.id.fl_activity_search);        initData(mNames, mFlowLayout);    }    private void initData(String[] data, cflayout layout) {        LayoutInflater inflater = LayoutInflater.from(this);        for (int i = 0; i < data.length; i++) {            TextView tv = (TextView) inflater.inflate(R.layout.activity_search_item_textview, layout,                    false);            tv.setText(data[i]);            layout.addView(tv);        }    }}