android - android Volley - Request.setSequence 没用？

Question

浏览 Volley 源代码，似乎 Request 的 setSequence 方法是无用的。在 RequestQueue.add(Request) 方法中，请求似乎是按照它们添加的原始顺序添加的，因为这行将表明：

request.setSequence(getSequenceNumber());

（getSequenceNumber() 只返回一个增量计数器）。有什么方法可以订购请求，或者我应该进一步破解 Volley 吗？

Answer 1

利用Priority

private Priority mPriority = Priority.LOW;

@Override
public Priority getPriority() {
    return mPriority;
}

public void setPriority(Priority priority) {
    mPriority = priority;
}

更多细节在这里。

Answer 2

你不能给 request 一个命令，但你可以让它们一个接一个地运行。为此，您需要实现自己的RequestQueue。

这是一个示例，它演示了如何使所有请求以相同的顺序执行，您将它们添加到队列中，因为它使用单线程执行。

// Copied from Volley.newRequestQueue(..); source code
File cacheDir = new File(context.getCacheDir(), "def_cahce_dir");

String userAgent = "volley/0";
try {
    String packageName = context.getPackageName();
    PackageInfo info = context.getPackageManager().getPackageInfo(packageName, 0);
    userAgent = packageName + "/" + info.versionCode;
} catch (PackageManager.NameNotFoundException e) {
}

if (stack == null) {
    if (Build.VERSION.SDK_INT >= 9) {
        stack = new HurlStack();
    } else {
        // Prior to Gingerbread, HttpUrlConnection was unreliable.
        // See: http://android-developers.blogspot.com/2011/09/androids-http-clients.html
        stack = new HttpClientStack(AndroidHttpClient.newInstance(userAgent));
    }
}

int threadPoolSize = 1; // means only one request at a time
RequestQueue queue = new RequestQueue(new DiskBasedCache(cacheDir), network, threadPoolSize);
queue.start();