Android筆記:熱門标簽，流式布局

一、測試效果未成功

package cn.app.meiya.aa.widget;

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

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

/**
 * 類似話題标簽的流式布局,測試效果無效
 * http://www.apkbus.com/android-239725-1-1.html
 * Created by lonshine on 15/7/16.
 */
public class TopicFlowLayout extends ViewGroup {

    //存儲所有子View
    private List<List<View>> mAllChildViews = new ArrayList<>();
    //每一行的高度
    private List<Integer> mLineHeight = new ArrayList<>();

    public TopicFlowLayout(Context context) {
        this(context, null);
        // TODO Auto-generated constructor stub
    }

    public TopicFlowLayout(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
        // TODO Auto-generated constructor stub
    }

    public TopicFlowLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // TODO Auto-generated constructor stub
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // TODO Auto-generated method stub

        //父控件傳進來的寬度和高度以及對應的測量模式
        int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);
        int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
        int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);
        int modeHeight = MeasureSpec.getMode(heightMeasureSpec);

        //如果目前ViewGroup的寬高為wrap_content的情況
        int width = 0;//自己測量的 寬度
        int height = 0;//自己測量的高度
        //記錄每一行的寬度和高度
        int lineWidth = 0;
        int lineHeight = 0;

        //擷取子view的個數
        int childCount = getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = getChildAt(i);
            //測量子View的寬和高
            measureChild(child, widthMeasureSpec, heightMeasureSpec);
            //得到LayoutParams
            MarginLayoutParams lp = (MarginLayoutParams) getLayoutParams();
            //子View占據的寬度
            int childWidth = child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;
            //子View占據的高度
            int childHeight = child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin;
            //換行時候
            if (lineWidth + childWidth > sizeWidth) {
                //對比得到最大的寬度
                width = Math.max(width, lineWidth);
                //重置lineWidth
                lineWidth = childWidth;
                //記錄行高
                height += lineHeight;
                lineHeight = childHeight;
            } else {//不換行情況
                //疊加行寬
                lineWidth += childWidth;
                //得到最大行高
                lineHeight = Math.max(lineHeight, childHeight);
            }
            //處理最後一個子View的情況
            if (i == childCount - 1) {
                width = Math.max(width, lineWidth);
                height += lineHeight;
            }
        }
        //wrap_content
        setMeasuredDimension(modeWidth == MeasureSpec.EXACTLY ? sizeWidth : width,
                modeHeight == MeasureSpec.EXACTLY ? sizeHeight : height);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        // TODO Auto-generated method stub
        mAllChildViews.clear();
        mLineHeight.clear();
        //擷取目前ViewGroup的寬度
        int width = getWidth();

        int lineWidth = 0;
        int lineHeight = 0;
        //記錄目前行的view
        List<View> lineViews = new ArrayList<View>();
        int childCount = getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = getChildAt(i);
            MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
            int childWidth = child.getMeasuredWidth();
            int childHeight = child.getMeasuredHeight();

            //如果需要換行
            if (childWidth + lineWidth + lp.leftMargin + lp.rightMargin > width) {
                //記錄LineHeight
                mLineHeight.add(lineHeight);
                //記錄目前行的Views
                mAllChildViews.add(lineViews);
                //重置行的寬高
                lineWidth = 0;
                lineHeight = childHeight + lp.topMargin + lp.bottomMargin;
                //重置view的集合
                lineViews = new ArrayList();
            }
            lineWidth += childWidth + lp.leftMargin + lp.rightMargin;
            lineHeight = Math.max(lineHeight, childHeight + lp.topMargin + lp.bottomMargin);
            lineViews.add(child);
        }
        //處理最後一行
        mLineHeight.add(lineHeight);
        mAllChildViews.add(lineViews);

        //設定子View的位置
        int left = 0;
        int top = 0;
        //擷取行數
        int lineCount = mAllChildViews.size();
        for (int i = 0; i < lineCount; i++) {
            //目前行的views和高度
            lineViews = mAllChildViews.get(i);
            lineHeight = mLineHeight.get(i);
            for (int j = 0; j < lineViews.size(); j++) {
                View child = lineViews.get(j);
                //判斷是否顯示
                if (child.getVisibility() == View.GONE) {
                    continue;
                }
                MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
                int cLeft = left + lp.leftMargin;
                int cTop = top + lp.topMargin;
                int cRight = cLeft + child.getMeasuredWidth();
                int cBottom = cTop + child.getMeasuredHeight();
                //進行子View進行布局
                child.layout(cLeft, cTop, cRight, cBottom);
                left += child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;
            }
            left = 0;
            top += lineHeight;
        }

    }

    /**
     * 與目前ViewGroup對應的LayoutParams
     */
    @Override
    public LayoutParams generateLayoutParams(AttributeSet attrs) {
        // TODO Auto-generated method stub

        return new MarginLayoutParams(getContext(), attrs);
    }


}      

用法:

<font color="#362e2b"><font style="background-color:rgb(255, 255, 255)"><font face="Arial"><font style="font-size:14px">package com.czm.flowlayout;
 
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.ViewGroup.LayoutParams;
import android.view.ViewGroup.MarginLayoutParams;
import android.widget.TextView;
/**
 * 
 * @author caizhiming
 * @created on 2015-4-13
 */
public class MainActivity extends Activity {
 
    private String mNames[] = {
            "welcome","android","TextView",
            "apple","jamy","kobe bryant",
            "jordan","layout","viewgroup",
            "margin","padding","text",
            "name","type","search","logcat"
    };
    private XCFlowLayout mFlowLayout;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
         
        initChildViews();
         
    }
    private void initChildViews() {
        // TODO Auto-generated method stub
        mFlowLayout = (XCFlowLayout) findViewById(R.id.flowlayout);
        MarginLayoutParams lp = new MarginLayoutParams(
                LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
        lp.leftMargin = 5;
        lp.rightMargin = 5;
        lp.topMargin = 5;
        lp.bottomMargin = 5;
        for(int i = 0; i < mNames.length; i ++){
            TextView view = new TextView(this);
            view.setText(mNames[i]);
            view.setTextColor(Color.WHITE);
            view.setBackgroundDrawable(getResources().getDrawable(R.drawable.textview_bg));
            mFlowLayout.addView(view,lp);
        }
    }
 
}</font></font></font></font>      

package cn.app.meiya.aa.widget;

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

/**
 * http://www.bkjia.com/Androidjc/1013458.html
 * Created by lonshine on 15/7/16.
 */
public class FlowLayout extends ViewGroup {
    private float mVerticalSpacing; //每個item縱向間距
    private float mHorizontalSpacing; //每個item橫向間距

    public FlowLayout(Context context) {
        super(context);
    }
    public FlowLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }
    public void setHorizontalSpacing(float pixelSize) {
        mHorizontalSpacing = pixelSize;
    }
    public void setVerticalSpacing(float pixelSize) {
        mVerticalSpacing = pixelSize;
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int selfWidth = resolveSize(0, widthMeasureSpec);

        int paddingLeft = getPaddingLeft();
        int paddingTop = getPaddingTop();
        int paddingRight = getPaddingRight();
        int paddingBottom = getPaddingBottom();

        int childLeft = paddingLeft;
        int childTop = paddingTop;
        int lineHeight = 0;

        //通過計算每一個子控件的高度，得到自己的高度
        for (int i = 0, childCount = getChildCount(); i < childCount; ++i) {
            View childView = getChildAt(i);
            LayoutParams childLayoutParams = childView.getLayoutParams();
            childView.measure(
                    getChildMeasureSpec(widthMeasureSpec, paddingLeft + paddingRight,
                            childLayoutParams.width),
                    getChildMeasureSpec(heightMeasureSpec, paddingTop + paddingBottom,
                            childLayoutParams.height));
            int childWidth = childView.getMeasuredWidth();
            int childHeight = childView.getMeasuredHeight();

            lineHeight = Math.max(childHeight, lineHeight);

            if (childLeft + childWidth + paddingRight > selfWidth) {
                childLeft = paddingLeft;
                childTop += mVerticalSpacing + lineHeight;
                lineHeight = childHeight;
            } else {
                childLeft += childWidth + mHorizontalSpacing;
            }
        }

        int wantedHeight = childTop + lineHeight + paddingBottom;
        setMeasuredDimension(selfWidth, resolveSize(wantedHeight, heightMeasureSpec));
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int myWidth = r - l;

        int paddingLeft = getPaddingLeft();
        int paddingTop = getPaddingTop();
        int paddingRight = getPaddingRight();

        int childLeft = paddingLeft;
        int childTop = paddingTop;

        int lineHeight = 0;

        //根據子控件的寬高，計算子控件應該出現的位置。
        for (int i = 0, childCount = getChildCount(); i < childCount; ++i) {
            View childView = getChildAt(i);

            if (childView.getVisibility() == View.GONE) {
                continue;
            }

            int childWidth = childView.getMeasuredWidth();
            int childHeight = childView.getMeasuredHeight();

            lineHeight = Math.max(childHeight, lineHeight);

            if (childLeft + childWidth + paddingRight > myWidth) {
                childLeft = paddingLeft;
                childTop += mVerticalSpacing + lineHeight;
                lineHeight = childHeight;
            }
            childView.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
            childLeft += childWidth + mHorizontalSpacing;
        }
    }
}