java - Android AsyncTask 运行多次

Question

在我的应用程序中，有一个从数据库获取输入的按钮。当我在短时间内按多次时，它崩溃. 我如何使用asynctask避免这个错误？

show.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        showinf();
    }
});

}



private String[] columns={"name","surname"};
private void showinf(){

    SQLiteDatabase db=v1.getReadableDatabase();
    Cursor c=db.query("infos",columns,null,null, null,null,null);
    Random mn2=new Random();
    int count=c.getCount();
    String mn=String.valueOf(count);
    int i1=mn2.nextInt(count+1);
    c.move(i1);

    t1.setText(c.getString(c.getColumnIndex("name")));
    t2.setText(c.getString(c.getColumnIndex("surname")));




}

谢谢...

Answer 1

您可以创建一个 boolean 标志(比方说 bDiscardButtonAction )，并将其设置为 true在onPreExecute()并将其设置为 false在onPostExecute() ，类似于:

public class FooTask extends AsyncTask<Foo, Foo, Foo>
{
    private static boolean bDiscardButtonAction = false;
    private boolean isDiscareded = false;

    @Override
    public void onPreExecute()
    {
        if(bDiscardButtonAction)
        {
            isDiscareded = true;
            return;
        }

        bDiscardButtonAction = true;
    }

    @Override
    public Foo doInBackground(Foo... params)
    {
        if(isDiscareded) return;

        // ...
    }

    @Override
    public void onPostExecute(Void result)
    {
        if(!isDiscareded) bDiscardButtonAction = false;
    }

    @Override
    public void onCancelled(Foo result)
    {
        if(!isDiscareded) bDiscardButtonAction = false;
    }
}