解决ViewPager 高度wrap_content无效问题

最新推荐文章于 2024-03-18 10:16:29 发布

原创最新推荐文章于 2024-03-18 10:16:29 发布 · 231 阅读

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#移动开发

本文提供了一种解决 ViewPager 在设置为 wrap_content 时无法正常显示子内容的问题的方法。通过继承 ViewPager 并重写 onMeasure 方法，确保了 ViewPager 能够正确测量其高度，从而在布局中适当地展示其内容。

今天做了的项目中.用了tabhost,然后下边切换部分用的viewPager.当我把viewPager设置为wrap_content的时候,发现.怎么也不能显示其中的子内容.然后百度一顿搜.没找到真正能完成的结果.然后google.在stackflow里发现了老外解决了该问题.下边把代码下!

/**
 * ViewPager wrapContent解决方案
 */
public class WrapContentHeightViewPager extends ViewPager {/**
     * Constructor
     *
     * @param context the context
     */
    public WrapContentHeightViewPager(Context context) {
        super(context);
    }

    /**
     * Constructor
     *
     * @param context the context
     * @param attrs the attribute set
     */
    public WrapContentHeightViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

//    @Override//    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {//        super.onMeasure(widthMeasureSpec, heightMeasureSpec);//
//        // find the first child view//        View view = getChildAt(0);//        if (view != null) {//            // measure the first child view with the specified measure spec//            view.measure(widthMeasureSpec, heightMeasureSpec);//        }//
//        setMeasuredDimension(getMeasuredWidth(), measureHeight(heightMeasureSpec, view));//    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        int height = 0;
        for(int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
            int h = child.getMeasuredHeight();
            if(h > height) height = h;
        }

        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
    /**
     * Determines the height of this view
     *
     * @param measureSpec A measureSpec packed into an int
     * @param view the base view with already measured height
     *
     * @return The height of the view, honoring constraints from measureSpec
     */
    private int measureHeight(int measureSpec, View view) {
        int result = 0;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);

        if (specMode == MeasureSpec.EXACTLY) {
            result = specSize;
        } else {
            // set the height from the base view if available
            if (view != null) {
                result = view.getMeasuredHeight();
            }
            if (specMode == MeasureSpec.AT_MOST) {
                result = Math.min(result, specSize);
            }
        }
        return result;
    }

}

转载自： http://www.tuicool.com/articles/2YrmE3