Question

我正在尝试创建一个运行应用程序属性的应用程序，例如（进程名称，图标，内存等），并在listview中显示它们。

由于我在主线程中执行它们需要花费太多时间。如何在此示例循环中创建更多线程？（我是android编程的新手）

//would like to run this loop in parallel
for (int i = 0; i < processes.size(); i++) {
// calculations
}

Answer 1

尝试使用多个AsyncTasks并使用task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR)执行任务或使用多个线程并行处理。

<强>的AsyncTask

new AsyncTask<Void, Void, Void>() {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected Void doInBackground(Void... params) {
        //would like to run this loop in parallel
        //You can also start threads 

        for (int i = 0; i < processes.size(); i++) {
            // calculations
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
    }
}.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);

使用主题

Thread thread1 = new Thread(new Runnable() {
    @Override
    public void run() {
        for (int i = 0; i < processes.size() /2; i++) {
        // calculations
        }
    }
});

Thread thread2 = new Thread(new Runnable() {
    @Override
    public void run() {
        for (int i = processes.size() /2; i < processes.size(); i++) {
        // calculations
        }
    }
});

thread1.start();
thread1.start();

Answer 2

Hi I think you have one loop to iterate which is the data got from any Web Service.

 - Basically all the long running process which are need for UI changes can be run inside the AsyncTask, which will create background threads.

class AsyncExaple extends AsyncTask<Void, Void, Void>{

    @Override
    protected Void doInBackground(Void... params) {

        //What ever the long running tasks are run inside this block
        //would like to run this loop in parallel
        for (int i = 0; i < processes.size(); i++) {
// calculations
        }
        return null;
    }
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }
    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
    }
};


To call this AsyncTask do as follows

AsyncExaple asyncExaple = new AsyncExaple();
asyncExaple.execute();


If you still want to use the Threads use below code:

 new Thread(new Runnable() {
            @Override
            public void run() {

            }
        }).start();

如何使用线程减少android应用程序加载时间？

2 个答案: