圆角

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从 Android 12(API 级别 31)开始,您可以使用 RoundedCornerWindowInsets.getRoundedCorner(int position) 来设置圆角的半径和中心点。借助这些 API,您的应用可以避免界面元素在带有圆角的屏幕上被截断。该框架还提供了 getPrivacyIndicatorBounds() API,它会返回任何可见麦克风和摄像头指示标志的有界矩形。

在您的应用中实现这些 API 时,它们对具有非圆角屏幕的设备没有影响。

图片显示了一个圆角,并标注了半径和中心点
图 1:标注了半径和中心点的圆角

如需实现此功能,请相对于应用的边界通过 WindowInsets.getRoundedCorner(int position) 获取 RoundedCorner 信息。如果应用未占据整个屏幕,则该 API 通过让圆角的中心点基于应用的窗口边界来应用圆角。

以下代码段展示了一个简单的示例,说明了一个应用通过根据来自 RoundedCorner 的信息设置视图的外边距来避免界面截断。在本例中,它是右上角的圆角。

Kotlin

// Get the top-right rounded corner from WindowInsets.
val insets = rootWindowInsets
val topRight = insets.getRoundedCorner(RoundedCorner.POSITION_TOP_RIGHT) ?: return

// Get the location of the close button in window coordinates.
val location = IntArray(2)
closeButton!!.getLocationInWindow(location)
val buttonRightInWindow = location[0] + closeButton.width
val buttonTopInWindow = location[1]

// Find the point on the quarter circle with 45 degree angle.
val offset = (topRight.radius * Math.sin(Math.toRadians(45.0))).toInt()
val topBoundary = topRight.center.y - offset
val rightBoundary = topRight.center.x + offset

// Check whether the close button exceeds the boundary.
if (buttonRightInWindow < rightBoundary << buttonTopInWindow > topBoundary) {
   return
}

// Set the margin to avoid truncating.
val parentLocation = IntArray(2)
getLocationInWindow(parentLocation)
val lp = closeButton.layoutParams as FrameLayout.LayoutParams
lp.rightMargin = Math.max(buttonRightInWindow - rightBoundary, 0)
lp.topMargin = Math.max(topBoundary - buttonTopInWindow, 0)
closeButton.layoutParams = lp

Java

// Get the top-right rounded corner from WindowInsets.
final WindowInsets insets = getRootWindowInsets();
final RoundedCorner topRight = insets.getRoundedCorner(POSITION_TOP_RIGHT);
if (topRight == null) {
   return;
}

// Get the location of the close button in window coordinates.
int [] location = new int[2];
closeButton.getLocationInWindow(location);
final int buttonRightInWindow = location[0] + closeButton.getWidth();
final int buttonTopInWindow = location[1];

// Find the point on the quarter circle with a 45 degree angle.
final int offset = (int) (topRight.getRadius() * Math.sin(Math.toRadians(45)));
final int topBoundary = topRight.getCenter().y - offset;
final int rightBoundary = topRight.getCenter().x + offset;

// Check whether the close button exceeds the boundary.
if (buttonRightInWindow < rightBoundary << buttonTopInWindow > topBoundary) {
   return;
}

// Set the margin to avoid truncating.
int [] parentLocation = new int[2];
getLocationInWindow(parentLocation);
FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams) closeButton.getLayoutParams();
lp.rightMargin = Math.max(buttonRightInWindow - rightBoundary, 0);
lp.topMargin = Math.max(topBoundary - buttonTopInWindow, 0);
closeButton.setLayoutParams(lp);