Font.SourceIdentifier 屬性

public int SourceIdentifier { [Android.Runtime.Register("getSourceIdentifier", "()I", "", ApiSince=31)] get; }

[<get: Android.Runtime.Register("getSourceIdentifier", "()I", "", ApiSince=31)>]
member this.SourceIdentifier : int

屬性值

字型來源資料的唯一識別碼。

屬性

RegisterAttribute

備註

回傳來源字型資料的唯一 ID。

你可以將此識別碼用作快取的鍵值，或檢查兩個字型是否能透過字型變體設定插值。

<code>
              // Following three Fonts, fontA, fontB, fontC have the same identifier.
              Font fontA = new Font.Builder("/path/to/font").build();
              Font fontB = new Font.Builder(fontA).setTtcIndex(1).build();
              Font fontC = new Font.Builder(fontB).setFontVariationSettings("'wght' 700).build();

              // Following fontD has the different identifier from above three.
              Font fontD = new Font.Builder("/path/to/another/font").build();

              // Following fontE has different identifier from above four even the font path is the same.
              // To get the same identifier, please create new Font instance from existing fonts.
              Font fontE = new Font.Builder("/path/to/font").build();
</code>

這裡有一個快取字型物件的範例，具有

<code>
              private LongSparseArray<SparseArray<Font>> mCache = new LongSparseArray<>();

              private Font getFontWeightVariation(Font font, int weight) {
                  // Different collection index is treated as different font.
                  long key = ((long) font.getSourceIdentifier()) << 32 | (long) font.getTtcIndex();

                  SparseArray<Font> weightCache = mCache.get(key);
                  if (weightCache == null) {
                     weightCache = new SparseArray<>();
                     mCache.put(key, weightCache);
                  }

                  Font cachedFont = weightCache.get(weight);
                  if (cachedFont != null) {
                    return cachedFont;
                  }

                  Font newFont = new Font.Builder(cachedFont)
                      .setFontVariationSettings("'wght' " + weight);
                      .build();

                  weightCache.put(weight, newFont);
                  return newFont;
              }
</code>

Java 文件 android.graphics.fonts.Font.getSourceIdentifier()。

本頁部分內容為基於 Open Source Project 所創建與分享的作品，並依授權條款所描述的使用進行修改。