That is the real value of the z dimension: You can create objects in any order you choose and position them relative to each other by adjusting the z value on each object.

这就是 z 值的实际价值：您可以按照任何顺序来创建对象，并可以通过调整每个对象的 z 值来调整彼此之间的相对位置。

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This ensures that the exact value of the relative position is set only once, and you can later define a spacing between the two.

这确保了相对位置的精确值设置一次，以后你可以定义一个两者之间的间距。

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Specifies the top position, in pixels. This value is relative to the upper-left corner of the screen. The value must be greater than or equal to 0.

指定顶部的位置，以像素为单位。这个值是相对于屏幕的左上角。该值必须大于或等于0。

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