最近項(xiàng)目中需要Viewpager的高度能夠自適應(yīng)的動(dòng)態(tài)改變,如果直接設(shè)置viewpager的高度為Android:layout_height="wrap_content",并不起作用,viewpager會(huì)鋪滿父布局,通過(guò)閱讀viewpager的源碼,發(fā)現(xiàn)創(chuàng)建一個(gè)viewpager的子類并重寫onMeasure可實(shí)現(xiàn)這個(gè)需求,代碼如下:
public class WrapContentHeightViewPager extends ViewPager {
public WrapContentHeightViewPager(Context context) {
super(context);
}
public WrapContentHeightViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int childSize = getChildCount();
int maxHeight = 0;
for (int i = 0; i < childSize; i++) {
View child = getChildAt(i);
child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
if (child.getMeasuredHeight() > maxHeight) {
maxHeight = child.getMeasuredHeight();
}
}
if (maxHeight > 0) {
setMeasuredDimension(getMeasuredWidth(), maxHeight);
}
}
}
思路很簡(jiǎn)單,遍歷viewpager的每個(gè)childView,找出高度最大的那個(gè)childView的高度,并把這個(gè)高度設(shè)置為viewpager的高度。