[英]How do you show a loading screen while creating database?
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
loadData();
setContentView(R.layout.preload);
Thread thread = new Thread()
{
@Override
public void run() {
setUpDB();
setContentView(R.layout.main);
}
};
thread.start();
}
因此,我希望它在数据库设置(setUpDB)时显示预加载视图,然后在安装完成后切换到主视图,更改为主视图。 我几乎可以正常工作了; 显示加载器直到大约80%然后崩溃,但是现在我什至无法获取它来显示加载器...如果我在线程中有setUpDB()崩溃,如果我在线程外将其显示为空白屏幕,直到完全加载为止。 我不记得以前的代码了...有什么想法吗?
使用assynctask尝试此操作。
private class LoadAssync extends AsyncTask<String, Void, Void> { // Assync task
protected void onPreExecute() {
ProgressDialog dialog=ProgressDialog.show(this,"","Loading");
}
protected Void doInBackground(final String... args) {
setUpDB();
}
protected void onPostExecute(final Void unused) {
if (dialog.isShowing()) {
dialog.dismiss();
}
}
}
执行assynctask
LoadAssync mAsyync1;
mAsyync1 = new LoadAssync();
mAsyync1.execute(null);
声明一个处理程序,然后调用它来更新您的用户界面,
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ProgressDialog pd=ProgressDialog.show(this,"","Please Wait...");
Handler handler =new Handler()
{
public void handleMessage(Message msg)
{
if(msg.what==0)
{
pd.dismiss();
setContentView(R.layout.main);
}
}
};
Thread thread = new Thread()
{
@Override
public void run() {
loadData();
setUpDB();
handler.sendEmptyMEssage(0);
}
};
thread.start();
}
setUpDB();
splashHandler.sendEmptyMessageDelayed(STOP_SPLASH, STOP_SPLASH_DELAY);
private Handler splashHandler = new Handler() {
public void handleMessage(android.os.Message msg) {
switch (msg.what) {
case STOP_SPLASH:
progressbar.dismiss();
startActivity(new Intent(getApplicationContext(),
HomeScreenActivity.class));
finish();
break;
}
};
};
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