问题
I have an Android project where I should make Apples fall. The apples are painted in a Rect. So I created a function that change the Rect position and repaint. Here's my function :
private void updateApplesPosition() {
for(Rect rect:fallingDownFruitsList)
rect.set(rect.left, rect.top +10, rect.right, rect.bottom +10);
}
I have a problem : the Apples don't fall but go from right to left. To make the apples fall I changed the code by this :
private void updateApplesPosition() {
for(Rect rect:fallingDownFruitsList)
rect.set(rect.left+10, rect.top, rect.right+10, rect.bottom);
}
回答1:
This image will explain you in detail:
left The X coordinate of the left side of the rectangle
top The Y coordinate of the top of the rectangle
right The X coordinate of the right side of the rectangle
bottom The Y coordinate of the bottom of the rectangle
回答2:
From the docs
Parameters
left The X coordinate of the left side of the rectangle
top The Y coordinate of the top of the rectangle
right The X coordinate of the right side of the rectangle
bottom The Y coordinate of the bottom of the rectangle
来源：https://stackoverflow.com/questions/22589322/what-does-top-left-right-and-bottom-mean-in-android-rect-object