问 安卓- ConstraintLayout以编程方式设定高度百分比？

EN

正确的答案是：

ConstraintLayout mConstrainLayout = (ConstraintLayout) vw.findViewById(R.id.myclayout); ConstraintLayout.LayoutParams lp = (ConstraintLayout.LayoutParams) mConstrainLayout.getLayoutParams(); lp.matchConstraintPercentHeight = (float) 0.4; mConstrainLayout.setLayoutParams(lp);

我使用ConstraintSet更新了ConstraintLayout的子级的宽度和高度：

        val set = ConstraintSet()
        set.clone(parentLayout) // parentLayout is a ConstraintLayout
        set.constrainPercentWidth(childElement.id, .5f)
        set.constrainPercentHeight(childElement.id, .5f)
        set.applyTo(parentLayout)

...the浮动值应该是映射到单位间隔的百分比。

我有同样的问题，谢天谢地找到了这篇文章。我开发了一个虚拟乐器应用程序，一个钢鼓/平底锅应用程序，有八个不同的UI，主要元素是圆形的。我为八个UI中的每一个使用了一个所有屏幕大小的布局，以减少布局冗余，并希望在大多数具有不同屏幕分辨率的设备上保持循环元素的高宽比。因此，我不得不使用layout_constraintWidth_percent和layout_constraintHeight_percent根据设备屏幕纵横比调整父布局的大小。我使用了上面@初学者的代码，并将其与计算屏幕纵横比的代码相结合，从而实现了该思想。以下是代码：

// instantiate constraint layout inside OnCreate
ConstraintLayout mcLayout =findViewById(R.id.layout_myConstraintLayout);
//determine display aspect ratio
WindowManager wm = (WindowManager) 
this.getSystemService(Context.WINDOW_SERVICE);
assert wm != null;
Display display = wm.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
assert display != null;
display.getMetrics(metrics);
float width = metrics.widthPixels;
float height = metrics.heightPixels;
float ratio = width/height;
float aspectRatio = round(ratio, 2);
Log.d("DISPLAYRATIO", "Display Ration is: " + displayRatio);
// create contraintlayout set for mConstraintLayout and params
ConstraintSet set = new ConstraintSet();
ConstraintLayout.LayoutParams lp = (ConstraintLayout.LayoutParams) 
lowTenorBkg.getLayoutParams();
// set percent width and height acacording to screen display aspect ratio
if (aspectRatio > 1.30f && aspectRatio < 1.42f) {
    // Add constraints
    lp.matchConstraintPercentWidth = 0.96f;
    lp.matchConstraintPercentHeight = 0.78f;
} else if (aspectRatio > 1.40f && aspectRatio < 1.60f) {
    // Add constraints
    lp.matchConstraintPercentWidth = 0.96f;
    lp.matchConstraintPercentHeight = 0.83f;
} else if (aspectRatio > 1.58f && aspectRatio < 1.67f) {
    // Add constraints
    lp.matchConstraintPercentWidth = 0.96f;
    lp.matchConstraintPercentHeight = 0.93f;
} else if (aspectRatio > 1.65f && aspectRatio <= 1.71f) {
    // Add constraints
    lp.matchConstraintPercentWidth = 0.92f;
    lp.matchConstraintPercentHeight = 0.94f;
} else if (aspectRatio > 1.72f && aspectRatio <= 1.78f) {
    // Add constraints
    lp.matchConstraintPercentWidth = 0.875f;
    lp.matchConstraintPercentHeight = 0.94f;
} else if (aspectRatio > 1.78f && aspectRatio <= 2.05f) {
    // Add constraints
    lp.matchConstraintPercentWidth = 0.8f;
    lp.matchConstraintPercentHeight = 0.93f;
lowTenorBkg.setLayoutParams(lp);
set.applyTo(mcLayout);