据我了解,在不修改 Android 平台源代码(至少版本 2.3 和 4)的情况下,不可能同时连接 3g 和 WiFi。主要问题是在frameworks/base/core/res/res/values/config.xml中定义的连接的硬编码优先级:
<!-- This string array should be overridden by the device to present a list of network
attributes. This is used by the connectivity manager to decide which networks can coexist
based on the hardware -->
<!-- An Array of "[Connection name],[ConnectivityManager connection type],
[associated radio-type],[priority] -->
<!-- ^^^^^^^^^^---------- Connection priority -->
<string-array translatable="false" name="networkAttributes">
<item>"wifi,1,1,1"</item>
<item>"mobile,0,0,0"</item>
<item>"mobile_mms,2,0,2"</item>
<item>"mobile_supl,3,0,2"</item>
<item>"mobile_hipri,5,0,3"</item>
</string-array>
然后订阅连接/断开事件的ConnectivityService读取此 config.xml 。在连接处理程序中,它决定它应该如何处理其他连接:
private void handleConnect(NetworkInfo info) {
//------------8-<--------------------------
// if this is a default net and other default is running
// kill the one not preferred
if (mNetAttributes[type].isDefault()) {
if (mActiveDefaultNetwork != -1 && mActiveDefaultNetwork != type) {
if ((type != mNetworkPreference &&
mNetAttributes[mActiveDefaultNetwork].mPriority >
// ^^^^^^^^^ --- From config.xml
mNetAttributes[type].mPriority) ||
// ^^^^^^^^^-------- From config.xml
mNetworkPreference == mActiveDefaultNetwork) {
// don't accept this one
if (DBG) Slog.v(TAG, "Not broadcasting CONNECT_ACTION " +
"to torn down network " + info.getTypeName());
teardown(thisNet);
return;
//------------8-<--------------------------