將 dp 和 sp 轉換為畫素

當你需要為 Paint.setTextSize 設定畫素值但仍希望根據裝置進行縮放時，你可以轉換 dp 和 sp 值。

DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
float pixels = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 12f, metrics);

DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
float pixels = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 12f, metrics);

或者，如果你有要載入資源的上下文，則可以將維度資源轉換為畫素。

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <dimen name="size_in_sp">12sp</dimen>
    <dimen name="size_in_dp">12dp</dimen>
</resources>

// Get the exact dimension specified by the resource
float pixels = context.getResources().getDimension(R.dimen.size_in_sp);
float pixels = context.getResources().getDimension(R.dimen.size_in_dp);

// Get the dimension specified by the resource for use as a size.
// The value is rounded down to the nearest integer but is at least 1px.
int pixels = context.getResources().getDimensionPixelSize(R.dimen.size_in_sp);
int pixels = context.getResources().getDimensionPixelSize(R.dimen.size_in_dp);

// Get the dimension specified by the resource for use as an offset.
// The value is rounded down to the nearest integer and can be 0px.
int pixels = context.getResources().getDimensionPixelOffset(R.dimen.size_in_sp);
int pixels = context.getResources().getDimensionPixelOffset(R.dimen.size_in_dp);