GVariantBuilder 构建 a(ii) 或 a(vv)

【问题标题】：GVariantBuilder build a(ii) or a(vv)GVariantBuilder 构建 a(ii) 或 a(vv)
【发布时间】：2020-05-25 06:15:27
【问题描述】：

我想通过 dbus 发送这个包含 2 个 int 的数组。它总是抱怨 value 不是 tuple 或 null 类型取决于尝试。它需要什么样子？

    GVariantBuilder builder;
    g_variant_builder_init(&builder, G_VARIANT_TYPE("a(ii)"));
    g_variant_builder_add(&builder, "(ii)", 99, 99);
    g_variant_builder_add(&builder, "(ii)", 98, 98);
    GVariant *value = g_variant_new("a(ii)", &builder);
    g_dbus_method_invocation_return_value(invocation, value));

    //g_dbus_method_invocation_return_value(invocation, &value)); - also tried

     //Previous attempts
    //GVariantBuilder *builder; 
    // builder = g_variant_builder_new(G_VARIANT_TYPE("a(ii)"));
    //g_variant_builder_add(&builder, "(ii)", 99, 99);
    //g_variant_builder_add(&builder, "(ii)", 98, 98);
    //and
    //g_variant_builder_add(builder, "(ii)", 99, 99);
   //g_variant_builder_add(builder, "(ii)", 98, 98);

【问题讨论】：

标签： c glib gvariant

【解决方案1】：

GVariantBuilder 不打算用作GVariant 的有效负载：它是一个builder pattern object，它将根据其内容构造GVariant：

GVariantBuilder builder;

// Initialize the GVariantBuilder with the final type
g_variant_builder_init (&builder, G_VARIANT_TYPE ("a(ii)"));

// Add the contents of the variant
g_variant_builder_add (&builder, "(ii)", 99, 99);
g_variant_builder_add (&builder, "(ii)", 98, 98);

// Construct the variant from the builder
GVariant *v = g_variant_builder_end (&builder);

您应该查看g_variant_builder_init() 和g_variant_builder_end() 的文档以了解更多信息。

【讨论】：