Question

我在启动画面中使用Asynctask将数据库项添加到数据库中。插入过程进展顺利，但启动视图不会显示。

我在下面发布我的代码，任何建议将不胜感激。 THX

splash.xml

<RelativeLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:background="@drawable/splash">


</RelativeLayout>

Splash.java

public class Splash extends Activity {

     private ChannelDB mDB;
     private TextView loading;
     private String channelS_TABLE;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.splash);  
        new SetDB().execute();

    }

    private class SetDB extends AsyncTask<String, String, String> {

        @Override
        protected String doInBackground(String... arg0) {
            // TODO Auto-generated method stub
            try {
                if (tabIsExist(channelS_TABLE) !=true){
                    **some database insert**  
                }else{
                    synchronized(this){
                        Log.i("Splash", "the table is there");
                        wait(3000);}
                    Intent i = new Intent();
                    i.setClassName("com.appkon.hdtvs",
                                   "com.appkon.hdtvs.HDtvs");
                    finish();
                    startActivity(i);
                }   
               }catch (Exception e) {

                    Log.i("Splash", "setDB exception");
                        Intent i = new Intent();
                        i.setClassName("com.appkon.hdtvs",
                                       "com.appkon.hdtvs.HDtvs");
                        finish();
                        startActivity(i);
                    }
            return null;
        }


        protected void onPreExecute(String load) {
            synchronized (this) { try {
                wait(2000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } }
        }

        protected void onPostExecute(String finish) {
             Intent i = new Intent();
             i.setClassName("com.appkon.hdtvs",
                            "com.appkon.hdtvs.HDtvs");
             finish();
             startActivity(i);
        }
    }


        public boolean tabIsExist(String tableName){
            boolean result = false;
            if(tableName == null){
                    return false;
            }
            Cursor cursor= ChannelDB.check();
            startManagingCursor(cursor);
            try {
                    if(cursor.moveToNext()){
                            int count = cursor.getInt(0);
                            if(count>0){
                                    result = true;
                            }
                    }

            } catch (Exception e) {
                Log.e(this.toString(),"error:"+e.toString());
                Intent intent = new Intent(this,HDtvs.class);  
                startActivity(intent);  
                this.finish(); 
            }                
            return result;
        }


    }

我更改了xml

<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:background="@drawable/splash">

  <ImageView android:id="@+id/bg"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:background="@drawable/splash"/>

</LinearLayout>

仍然无效，数据库插入也不起作用。

Answer 1

RelativeLayout是一个容器。只有在其中包含一些元素/视图时才会显示其背景。虽然我不确定。但您可以尝试此操作 - 从RelativeLayout的背景中删除图片，并在ImageView内创建RelativeLayout，并将ImageView's源图片设置为您想要的图片。你应该得到想要的结果。

在使用布局视图调试AsyncTask时需要帮助

1 个答案: