android - Android：根据宽度在 XML 中设置按钮高度

Question

我正在处理 android XML 中的布局，我想在设置填充父项时设置按钮高度以匹配它的宽度。显然这个数字会根据屏幕大小而变化，所以我不能使用设置的像素大小。有人可以帮助我根据屏幕尺寸获取按钮宽度，然后将其传递给高度设置吗？

谢谢你，乔什

Answer 1

我曾经遇到过类似的问题，但没有找到仅适用于 XML 的解决方案。您必须编写自己的 Button-Class 并覆盖 [ onMeassure][1] 方法。

例子：

/**
 * @see android.view.View#measure(int, int)
 */
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    setMeasuredDimension(measureWidth(widthMeasureSpec), measureHeight(heightMeasureSpec));
}

private int width; // saves the meassured width


/**
 * Determines the width of this view
 * 
 * @param measureSpec
 *            A measureSpec packed into an int
 * @return The width of the view, honoring constraints from measureSpec
 */
private int measureWidth(int measureSpec) {
    int result = 30;
    int specMode = MeasureSpec.getMode(measureSpec);
    int specSize = MeasureSpec.getSize(measureSpec);

    if (specMode == MeasureSpec.EXACTLY) {
        // We were told how big to be
        result = specSize;
    } else {
        result =1123; // meassure your with here somehow
        if (specMode == MeasureSpec.AT_MOST) {
            // Respect AT_MOST value if that was what is called for by measureSpec
            result = Math.min(result, specSize);
        }
    }
            width = result;
    return result;
}

/**
 * Determines the height of this view
 * 
 * @param measureSpec
 *            A measureSpec packed into an int
 * @return The height of the view, honoring constraints from measureSpec
 */
private int measureHeight(int measureSpec) {
    int result = 0;
    int specMode = MeasureSpec.getMode(measureSpec);
    int specSize = MeasureSpec.getSize(measureSpec);

    if (specMode == MeasureSpec.EXACTLY) {
        // We were told how big to be
        result = specSize;
    } else {
        result = width;
        if (specMode == MeasureSpec.AT_MOST) {
            // Respect AT_MOST value if that was what is called for by measureSpec
            result = Math.min(result, specSize);
        }
    }

    return result;
}

[1]： http: //developer.android.com/reference/android/view/View.html#onMeasure (int , int)

Answer 2

代替PX使用Pixel size，提到dip（即设备独立像素），dip会根据设备屏幕大小独立取像素大小。

例如：android:textSize="12dip"

您可以使用dip或dp。

享受！！