下载大量数据时应用程序无响应

Question

我有一个应用必须在应用启动时从服务器下载几 MB (1MB - 10MB) 的数据。

问题在于应用：

• 在开始下载之前不显示主TextView（屏幕保持黑色）

• 或多或少没有反应

代码如下：

public class Main extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        DoIt();
    }

    private void DoIt() {

        HttpClient httpClient = new DefaultHttpClient();

        TextView tv = (TextView)findViewById(R.id.textView);
        tv.setText("Starting app...");

        try {        
            for (int i=1; i<100; i++) {
                HttpPost request2 = new HttpPost("http://192.168.1.12:3000/bytes/data" + i);            
                HttpResponse response2 = httpClient.execute(request2);

               // Do something with data. In some cases, it has to download 1MB data
            } 
        }

        // catch + finally ...
    }
}

如何防止应用无响应？

Answer 1

您的应用程序变得不负责任，因为您在主线程中下载文件，您应该使用这样的后台线程

 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    TextView tv = (TextView)findViewById(R.id.textView);
    tv.setText("Starting app...");

    new Thread(new Runnable() {
        @Override
        public void run() {
            DoIt();
        }
    }).start();

}

 private void DoIt() {

    HttpClient httpClient = new DefaultHttpClient();

    try {        
        for (int i=1; i<100; i++) {
            HttpPost request2 = new HttpPost("http://192.168.1.12:3000/bytes/data" + i);            
            HttpResponse response2 = httpClient.execute(request2);

           // Do something with data. In some cases, it has to download 1MB data
        } 
    }

    // catch + finally ...
}

我认为这应该可行