如何在 MediaStore 中更新()图像

How to update() an image in MediaStore

query MediaStore,我只需创建一个具有正确 "base URI" 的 URI 并附加 IMAGE_ID(我从相应的缩略图中获得)。然后,我简单地调用内容解析器来获取游标:

    Long IMAGE_ID = 172712; // let's say we have this IMAGE_ID
    Uri baseUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
    baseUri = Uri.withAppendedPath(baseUri, ""+ IMAGE_ID);

    // let's just get this one field, description
    String[] projection = {MediaStore.Images.Media.DESCRIPTION};

    Cursor c = getContext().getContentResolver().query(baseUri, projection, null, null, null);
    if (!c.moveToFirst()) return -1; 
    String description = c.getString(0);  // and we're done :-)

但是,如果我想设置 MediaStore.Images.Media.DESCRIPTION 字段怎么办?我可以以某种方式调用 update 方法吗?

    Long IMAGE_ID = 172712; // same image...
    Uri baseUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
    baseUri = Uri.withAppendedPath(baseUri, ""+ IMAGE_ID);

    // create an object with the value to set
    ContentValues test_values = new ContentValues();
    test_values.put(MediaStore.Images.Media.DESCRIPTION, "Some image text...");

    // i.e., SQL like: UPDATE MEDIASTORE SET DESCRIPTION = "Some image text..." WHERE IMAGE_ID = 172712;
    String sIMAGE_ID = "" + IMAGE_ID;
    int res = getContext().getContentResolver().update(baseUri, test_values, MediaStore.Images.Media._ID + "= ?", new String[]{sIMAGE_ID });  // works fine!

以上代码运行良好(至少在模拟器、Nexus 7 设备上)! update 设置描述 "field".