android 自定义ViewGroup实现可记载并呈现选择的ListView

转载请注明出处：王亟亟的大牛之路

之前也做过一些用TextView之类的记录ListView选项的东西，但是总觉得好难看，发现个不错的实现就贴给大家。

项目目录

运行效果：

自定义视图：

@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
public class FlowLayout extends ViewGroup {

    private int mGravity = (isIcs() ? Gravity.START : Gravity.LEFT) | Gravity.TOP;

    private final List<List<View>> mLines = new ArrayList<List<View>>();
    private final List<Integer> mLineHeights = new ArrayList<Integer>();
    private final List<Integer> mLineMargins = new ArrayList<Integer>();

    public FlowLayout(Context context) {
        this(context, null);
    }

    public FlowLayout(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public FlowLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        TypedArray a = context.obtainStyledAttributes(attrs,
                R.styleable.FlowLayout, defStyle, 0);

        try {
            int index = a.getInt(R.styleable.FlowLayout_android_gravity, -1);
            if(index > 0) {
                setGravity(index);
            }
        } finally {
            a.recycle();
        }

    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        int sizeWidth = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();
        int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);

        int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
        int modeHeight = MeasureSpec.getMode(heightMeasureSpec);

        int width = 0;
        int height = getPaddingTop() + getPaddingBottom();

        int lineWidth = 0;
        int lineHeight = 0;

        int childCount = getChildCount();

        for(int i = 0; i < childCount; i++) {

            View child = getChildAt(i);
            boolean lastChild = i == childCount - 1;

            if(child.getVisibility() == View.GONE) {

                if(lastChild) {
                    width = Math.max(width, lineWidth);
                    height += lineHeight;
                }

                continue;
            }

            measureChildWithMargins(child, widthMeasureSpec, lineWidth, heightMeasureSpec, height);

            LayoutParams lp = (LayoutParams) child.getLayoutParams();

            int childWidthMode = MeasureSpec.AT_MOST;
            int childWidthSize = sizeWidth;

            int childHeightMode = MeasureSpec.AT_MOST;
            int childHeightSize = sizeHeight;

            if(lp.width == LayoutParams.MATCH_PARENT) {
                childWidthMode = MeasureSpec.EXACTLY    ;
                childWidthSize -= lp.leftMargin + lp.rightMargin;
            } else if(lp.width >= 0) {
                childWidthMode = MeasureSpec.EXACTLY;
                childWidthSize = lp.width;
            }

            if(lp.height >= 0) {
                childHeightMode = MeasureSpec.EXACTLY;
                childHeightSize = lp.height;
            } else if (modeHeight == MeasureSpec.UNSPECIFIED) {
                childHeightMode = MeasureSpec.UNSPECIFIED;
                childHeightSize = 0;
            }

            child.measure(
                    MeasureSpec.makeMeasureSpec(childWidthSize, childWidthMode),
                    MeasureSpec.makeMeasureSpec(childHeightSize, childHeightMode)
            );

            int childWidth = child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;

            if(lineWidth + childWidth > sizeWidth) {

                width = Math.max(width, lineWidth);
                lineWidth = childWidth;

                height += lineHeight;
                lineHeight = child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin;

            } else {
                lineWidth += childWidth;
                lineHeight = Math.max(lineHeight, child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin);
            }

            if(lastChild) {
                width = Math.max(width, lineWidth);
                height += lineHeight;
            }

        }

        width += getPaddingLeft() + getPaddingRight();

        setMeasuredDimension(
                (modeWidth == MeasureSpec.EXACTLY) ? sizeWidth : width,
                (modeHeight == MeasureSpec.EXACTLY) ? sizeHeight : height);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {

        mLines.clear();
        mLineHeights.clear();
        mLineMargins.clear();

        int width = getWidth();
        int height = getHeight();

        int linesSum = getPaddingTop();

        int lineWidth = 0;
        int lineHeight = 0;
        List<View> lineViews = new ArrayList<View>();

        float horizontalGravityFactor;
        switch ((mGravity & Gravity.HORIZONTAL_GRAVITY_MASK)) {
            case Gravity.LEFT:
            default:
                horizontalGravityFactor = 0;
                break;
            case Gravity.CENTER_HORIZONTAL:
                horizontalGravityFactor = .5f;
                break;
            case Gravity.RIGHT:
                horizontalGravityFactor = 1;
                break;
        }

        for(int i = 0; i < getChildCount(); i++) {

            View child = getChildAt(i);

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

            LayoutParams lp = (LayoutParams) child.getLayoutParams();

            int childWidth = child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;
            int childHeight = child.getMeasuredHeight() + lp.bottomMargin + lp.topMargin;

            if(lineWidth + childWidth > width) {
                mLineHeights.add(lineHeight);
                mLines.add(lineViews);
                mLineMargins.add((int) ((width - lineWidth) * horizontalGravityFactor) + getPaddingLeft());

                linesSum += lineHeight;

                lineHeight = 0;
                lineWidth = 0;
                lineViews = new ArrayList<View>();
            }

            lineWidth += childWidth;
            lineHeight = Math.max(lineHeight, childHeight);
            lineViews.add(child);
        }

        mLineHeights.add(lineHeight);
        mLines.add(lineViews);
        mLineMargins.add((int) ((width - lineWidth) * horizontalGravityFactor) + getPaddingLeft());

        linesSum += lineHeight;

        int verticalGravityMargin = 0;
        switch ((mGravity & Gravity.VERTICAL_GRAVITY_MASK)  ) {
            case Gravity.TOP:
            default:
                break;
            case Gravity.CENTER_VERTICAL:
                verticalGravityMargin = (height - linesSum) / 2;
                break;
            case Gravity.BOTTOM:
                verticalGravityMargin = height - linesSum;
                break;
        }

        int numLines = mLines.size();

        int left;
        int top = getPaddingTop();

        for(int i = 0; i < numLines; i++) {

            lineHeight = mLineHeights.get(i);
            lineViews = mLines.get(i);
            left = mLineMargins.get(i);

            int children = lineViews.size();

            for(int j = 0; j < children; j++) {

                View child = lineViews.get(j);

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

                LayoutParams lp = (LayoutParams) child.getLayoutParams();

                // if height is match_parent we need to remeasure child to line height
                if(lp.height == LayoutParams.MATCH_PARENT) {
                    int childWidthMode = MeasureSpec.AT_MOST;
                    int childWidthSize = lineWidth;

                    if(lp.width == LayoutParams.MATCH_PARENT) {
                        childWidthMode = MeasureSpec.EXACTLY;
                    } else if(lp.width >= 0) {
                        childWidthMode = MeasureSpec.EXACTLY;
                        childWidthSize = lp.width;
                    }

                    child.measure(
                            MeasureSpec.makeMeasureSpec(childWidthSize, childWidthMode),
                            MeasureSpec.makeMeasureSpec(lineHeight - lp.topMargin - lp.bottomMargin, MeasureSpec.EXACTLY)
                    );
                }

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

                int gravityMargin = 0;

                if(Gravity.isVertical(lp.gravity)) {
                    switch (lp.gravity) {
                        case Gravity.TOP:
                        default:
                            break;
                        case Gravity.CENTER_VERTICAL:
                        case Gravity.CENTER:
                            gravityMargin = (lineHeight - childHeight - lp.topMargin - lp.bottomMargin) / 2 ;
                            break;
                        case Gravity.BOTTOM:
                            gravityMargin = lineHeight - childHeight - lp.topMargin - lp.bottomMargin;
                            break;
                    }
                }

                child.layout(left + lp.leftMargin,
                        top + lp.topMargin + gravityMargin + verticalGravityMargin,
                        left + childWidth + lp.leftMargin,
                        top + childHeight + lp.topMargin + gravityMargin + verticalGravityMargin);

                left += childWidth + lp.leftMargin + lp.rightMargin;

            }

            top += lineHeight;
        }

    }

    @Override
    protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
        return new LayoutParams(p);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public LayoutParams generateLayoutParams(AttributeSet attrs) {
        return new LayoutParams(getContext(), attrs);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
    }

    @TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
    public void setGravity(int gravity) {
        if(mGravity != gravity) {
            if((gravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK) == 0) {
                gravity |= isIcs() ? Gravity.START : Gravity.LEFT;
            }

            if((gravity & Gravity.VERTICAL_GRAVITY_MASK) == 0) {
                gravity |= Gravity.TOP;
            }

            mGravity = gravity;
            requestLayout();
        }
    }

    public int getGravity() {
        return mGravity;
    }

    /**
     * @return <code>true</code> if device is running ICS or grater version of Android.
     */
    private static boolean isIcs() {
        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH;
    }

    public static class LayoutParams extends MarginLayoutParams {

        public int gravity = -1;

        public LayoutParams(Context c, AttributeSet attrs) {
            super(c, attrs);

            TypedArray a = c.obtainStyledAttributes(attrs, R.styleable.FlowLayout_Layout);

            try {
                gravity = a.getInt(R.styleable.FlowLayout_Layout_android_layout_gravity, -1);
            } finally {
                a.recycle();
            }
        }

        public LayoutParams(int width, int height) {
            super(width, height);
        }

        public LayoutParams(ViewGroup.LayoutParams source) {
            super(source);
        }

    }

}

分析：

这部分主要是呈现被选项的实现，伸手党可以无视

对象：

public class Filter_Object {
    public String mName ;
    public boolean mIsSelected ;
}

分析：填充是否被选，以及listView每一行的显示内容

MainActivity:

public class MainActivity extends AppCompatActivity {
    private ListView mListView;
    private ArrayList<Filter_Object> mArrFilter;
    private ScrollView mScrollViewFilter;
    private Filter_Adapter mFilter_Adapter ;
    private FlowLayout mFlowLayoutFilter ;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {

            getWindow().setStatusBarColor(getResources().getColor(R.color.themecolor));
        }

        mArrFilter = new ArrayList<>();

        String[] strArr = getResources().getStringArray(R.array.city);

        int lengthOfstrArr = strArr.length;

        for (int i = 0; i < lengthOfstrArr; i++) {
            Filter_Object filter_object = new Filter_Object();
            filter_object.mName = strArr[i];
            filter_object.mIsSelected = false;
            mArrFilter.add(filter_object);
        }

        getSupportActionBar().setDisplayShowTitleEnabled(true);
        getSupportActionBar().setTitle(getString(R.string.app_name));

        mListView = (ListView) findViewById(R.id.listViewFilter);
        mScrollViewFilter = (ScrollView)findViewById(R.id.scrollViewFilter);
        //放置被选项的布局
        mFlowLayoutFilter = (FlowLayout)findViewById(R.id.flowLayout);

        mFilter_Adapter = new Filter_Adapter(mArrFilter);
        mListView.setAdapter(mFilter_Adapter);
    }
    public void addFilterTag() {
        final ArrayList<Filter_Object> arrFilterSelected = new ArrayList<>();

        mFlowLayoutFilter.removeAllViews();

        int length = mArrFilter.size();
        boolean isSelected = false;
        for (int i = 0; i < length; i++) {
            Filter_Object fil = mArrFilter.get(i);
            if (fil.mIsSelected) {
                isSelected = true;
                arrFilterSelected.add(fil);
            }
        }
        if (isSelected) {
            mScrollViewFilter.setVisibility(View.VISIBLE);
        } else {
            mScrollViewFilter.setVisibility(View.GONE);
        }
        int size = arrFilterSelected.size();
        LayoutInflater layoutInflater = (LayoutInflater)
                this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        for (int i = 0; i < size; i++) {
            View view = layoutInflater.inflate(R.layout.filter_tag_edit, null);

            TextView tv = (TextView) view.findViewById(R.id.tvTag);
            LinearLayout linClose = (LinearLayout) view.findViewById(R.id.linClose);
            final Filter_Object filter_object = arrFilterSelected.get(i);
            linClose.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    //showToast(filter_object.name);


                    int innerSize = mArrFilter.size();
                    for (int j = 0; j < innerSize; j++) {
                        Filter_Object mFilter_Object = mArrFilter.get(j);
                        if (mFilter_Object.mName.equalsIgnoreCase(filter_object.mName)) {
                            mFilter_Object.mIsSelected = false;

                        }
                    }
                    addFilterTag();
                    mFilter_Adapter.updateListView(mArrFilter);
                }
            });


            tv.setText(filter_object.mName);
            int color = getResources().getColor(R.color.themecolor);

            View newView = view;
            newView.setBackgroundColor(color);

            FlowLayout.LayoutParams params = new FlowLayout.LayoutParams(FlowLayout.LayoutParams.WRAP_CONTENT, FlowLayout.LayoutParams.WRAP_CONTENT);
            params.rightMargin = 10;
            params.topMargin = 5;
            params.leftMargin = 10;
            params.bottomMargin = 5;

            newView.setLayoutParams(params);

            mFlowLayoutFilter.addView(newView);
        }
    }

    public class Filter_Adapter extends BaseAdapter {
        ArrayList<Filter_Object> arrMenu;

        public Filter_Adapter(ArrayList<Filter_Object> arrOptions) {
            this.arrMenu = arrOptions;
        }

        public void updateListView(ArrayList<Filter_Object> mArray) {
            this.arrMenu = mArray;
            notifyDataSetChanged();
        }

        @Override
        public int getCount() {
            return this.arrMenu.size();
        }

        @Override
        public Object getItem(int position) {
            return null;
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }

        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
            ViewHolder viewHolder;
            if (convertView == null) {
                convertView = getLayoutInflater().inflate(R.layout.filter_list_item, null);
                viewHolder = new ViewHolder();
                viewHolder.mTtvName = (TextView) convertView.findViewById(R.id.tvName);
                viewHolder.mTvSelected = (TextView) convertView.findViewById(R.id.tvSelected);
                convertView.setTag(viewHolder);
            } else {
                viewHolder = (ViewHolder) convertView.getTag();
            }
            final Filter_Object mService_Object = arrMenu.get(position);
            viewHolder.mTtvName.setText(mService_Object.mName);

            if (mService_Object.mIsSelected) {
                viewHolder.mTvSelected.setVisibility(View.VISIBLE);
            } else {
                viewHolder.mTvSelected.setVisibility(View.INVISIBLE);
            }
            convertView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    mService_Object.mIsSelected = !mService_Object.mIsSelected;
                    mScrollViewFilter.setVisibility(View.VISIBLE);

                    addFilterTag();
                    notifyDataSetChanged();
                }
            });
            return convertView;
        }

        public class ViewHolder {
            TextView mTtvName, mTvSelected;

        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        // getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

分析：

层次很分明，从填充本地数据–>转载入ListView–>附加逻辑–>呈现。等流程思路很清晰，可读性很强。

具体使用，可以看源码，一目了然。
源码地址：http://yunpan.cn/cdbbFUd8rLFmJ 访问密码 af07