我有一个登录屏幕,成功登录后,它完成并显示另一个包含用户信息的页面。
我还阅读了很多关于我们如何扩展 Application 类的内容,但我仍然无法运行这段代码。
您可以在下面找到我的代码,我也会解释错误。
这就是我使用 Volley 调用 AsyncTask 的方式:
错误类似于 no activity for token android.os.BinderProxy
当我调用 startActivity(intent);
时它会出现。
我知道这个错误是因为活动被杀死并且 Volley 响应后的 AsyncTask 想要使用被杀死的上下文,但我不知道如何修复它。
Util.request_function(
activity,
MainActivity.user_session,
key_value,
new VolleyCallback() {
@Override
public void onSuccess(JSONObject result, Context context) {
Activity activity =
MyBaseActivity.myCustomApplication.getCurrentActivity();
Intent intent = new Intent(activity, SelfieCapture.class);
startActivity(intent);
finish();
}
@Override
public void onError(String result) {
}
});
我有如下接口:
排球回调.java:
public interface VolleyCallback {
void onSuccess(JSONObject result) throws JSONException;
void onError(String result) throws Exception;
}
工具.java
public static void request_function(Context context, CognitoUserSession cognitoUserSession, Map<String, String> key_value, final VolleyCallback callback) {
JSONObject jsonBody = new JSONObject();
CustomJSONObjectRequest postRequest = new CustomJSONObjectRequest(Request.Method.POST,
MainActivity.API_URL,
null,
response -> {
JSONObject jsonObject = (JSONObject) response;
//SoMe Stuff//
callback.onSuccess(null);
}, error -> {
//Log Error//
}){
@Override
public String getBodyContentType() {
return "application/json; charset=utf-8";
}
@Override
public Map<String, String> getHeaders() {
final Map<String, String> headers = new HashMap<>();
headers.put("Content-Type", "application/json");
return headers;
}
@Override
public byte[] getBody() {
return jsonBody.toString().getBytes();
}
};
// Request added to the RequestQueue
VolleyController.getInstance(context).addToRequestQueue(postRequest);
我的自定义应用程序.java
public class MyCustomApplication extends Application {
private Activity mCurrentActivity = null;
public void onCreate() {
super.onCreate();
}
public Activity getCurrentActivity() {
return mCurrentActivity;
}
public void setCurrentActivity(Activity mCurrentActivity) {
this.mCurrentActivity = mCurrentActivity;
}
}
MyBaseActivity.java
public class MyBaseActivity extends Activity {
public static MyCustomApplication myCustomApplication;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
myCustomApplication = (MyCustomApplication)this.getApplicationContext();
}
protected void onResume() {
super.onResume();
myCustomApplication.setCurrentActivity(this);
}
protected void onPause() {
clearReferences();
super.onPause();
}
protected void onDestroy() {
clearReferences();
super.onDestroy();
}
private void clearReferences(){
Activity currActivity = myCustomApplication.getCurrentActivity();
if (this.equals(currActivity))
myCustomApplication.setCurrentActivity(null);
}
}
原文由 Massoud 发布,翻译遵循 CC BY-SA 4.0 许可协议
这段代码似乎是正确的,但我唯一的怀疑是,当您想在
startActivity(intent)
中打开新活动时,会发生错误。因此,检查下一个名为
SelfieCapture.class
的触发类,看看它是否也从MyBaseActivity
扩展。还要考虑当你想得到
currentActivity
,如果你把它放在onCreate
,你会得到null
有关详细信息,请参阅 了解活动生命周期。