Android自定义控件 - 标签流式布局

Android自定义控件 - 标签流式布局

很简单，先看效果：

思路：

重写onMeasure计算childView宽度，如果当前ChildView放不下当前行,那么当前行剩余的空间由当前行其它控件平分，当前childView放入下一行，如果childView大于父View宽度，那么childView.width=ViewGroup.width。（如果子控件为GONE则不测量）

重写onMeasure (代码有点粗糙^_^)：

 @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;        }    }重写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;        }    }
完整代码：
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" />                    </com.example.demo.MyStreamLayout>