Android自定義控件 - 標籤流式佈局

Android自定義控件 - 標籤流式佈局

特點：水平佈局平分寬度、超出自動換行.

效果：

                     

思路：

重寫onMeasure計算childView寬度，如果當前ChildView放不下當前行,那麼當前行剩餘的空間由當前行其它控件平分，當前childView放入下一行，如果childView大於父View寬度，那麼childView.width=ViewGroup.width。（如果子控件爲GONE則不測量）

重寫onMeasure (代碼有點粗糙^_^)：

 @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int childCount = getChildCount();
        int measuredWidth = MeasureSpec.getSize(widthMeasureSpec);
        int currentWith = 0, visNum = 0;
        int key = 0;
        for (int i = 0; i < childCount; i++) {
            View childAt = getChildAt(i);
            if (childAt.getVisibility() == GONE) {
                key++;
                visNum++;
                continue;
            }
            childAt.measure(0, 0);
            int redWidth = childAt.getMeasuredWidth();
            if (redWidth + currentWith > getMeasuredWidth()) {
                int avgWidth = key < 1 ? 0 : (measuredWidth - currentWith) / (key - visNum);
                for (; key > 0; key--) {
                    View childView = getChildAt(i - key);
                    if (childView.getVisibility() == GONE)
                        continue;
                    int redWidth1 = childView.getMeasuredWidth();
                    int redHeight1 = childView.getMeasuredHeight();
                    redWidth1 += avgWidth;
                    int childMeasureWidth = MeasureSpec.makeMeasureSpec(redWidth1, MeasureSpec.EXACTLY);
                    int childMeasureHeight = MeasureSpec.makeMeasureSpec(redHeight1, MeasureSpec.EXACTLY);
                    childView.measure(childMeasureWidth, childMeasureHeight);
                }
                currentWith = 0;
                key = 0;
                visNum = 0;
            }
            key++;
            currentWith += redWidth;
        }
    }

重寫onLayout：

@Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int childCount = getChildCount();
        int currentWidth = 0, currentHeight = 0, maxHeight = 0;
        for (int i = 0; i < childCount; i++) {
            View childAt = getChildAt(i);
            if (childAt.getVisibility() == GONE)
                continue;
            int redWidth = childAt.getMeasuredWidth();
            int redHeight = childAt.getMeasuredHeight();
            maxHeight = redHeight > maxHeight ? redHeight : maxHeight;
            if (currentWidth + redWidth > r && currentWidth>0) {
                currentWidth = 0;
                currentHeight += maxHeight;
                maxHeight = 0;
            }
            redWidth = redWidth > (r - currentWidth) ? r - currentWidth : redWidth;
            setLayout(childAt, currentWidth, currentHeight, redWidth, redHeight);
            currentWidth += redWidth;




        }


    }

完整代碼：

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




public class MyStreamLayout extends ViewGroup {


    public MyStreamLayout(Context context) {
        super(context);
    }


    public MyStreamLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }


    public MyStreamLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }




    void setLayout(View v, int x, int y, int w, int h) {
        v.layout(x, y, w + x, h + y);
    }


    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int childCount = getChildCount();
        int measuredWidth = MeasureSpec.getSize(widthMeasureSpec);
        int currentWith = 0, visNum = 0;
        int key = 0;
        for (int i = 0; i < childCount; i++) {
            View childAt = getChildAt(i);
            if (childAt.getVisibility() == GONE) {
                key++;
                visNum++;
                continue;
            }
            childAt.measure(0, 0);
            int redWidth = childAt.getMeasuredWidth();
            if (redWidth + currentWith > getMeasuredWidth()) {
                int avgWidth = key < 1 ? 0 : (measuredWidth - currentWith) / (key - visNum);
                for (; key > 0; key--) {
                    View childView = getChildAt(i - key);
                    if (childView.getVisibility() == GONE)
                        continue;
                    int redWidth1 = childView.getMeasuredWidth();
                    int redHeight1 = childView.getMeasuredHeight();
                    redWidth1 += avgWidth;
                    int childMeasureWidth = MeasureSpec.makeMeasureSpec(redWidth1, MeasureSpec.EXACTLY);
                    int childMeasureHeight = MeasureSpec.makeMeasureSpec(redHeight1, MeasureSpec.EXACTLY);
                    childView.measure(childMeasureWidth, childMeasureHeight);
                }
                currentWith = 0;
                key = 0;
                visNum = 0;
            }
            key++;
            currentWith += redWidth;
        }
    }


    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int childCount = getChildCount();
        int currentWidth = 0, currentHeight = 0, maxHeight = 0;
        for (int i = 0; i < childCount; i++) {
            View childAt = getChildAt(i);
            if (childAt.getVisibility() == GONE)
                continue;
            int redWidth = childAt.getMeasuredWidth();
            int redHeight = childAt.getMeasuredHeight();
            maxHeight = redHeight > maxHeight ? redHeight : maxHeight;
            if (currentWidth + redWidth > r && currentWidth > 0) {
                currentWidth = 0;
                currentHeight += maxHeight;
                maxHeight = 0;
            }
            redWidth = redWidth > (r - currentWidth) ? r - currentWidth : redWidth;
            setLayout(childAt, currentWidth, currentHeight, redWidth, redHeight);
            currentWidth += redWidth;




        }


    }




}

使用：

        <com.example.demo.MyStreamLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">


            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="ChildView" />
            ......Other View
        </com.example.demo.MyStreamLayout>