public class MyDialogFragment extends DialogFragment {
public static MyDialogFragment newInstance() {
Bundle args = new Bundle();
MyDialogFragment fragment = new MyDialogFragment();
fragment.setArguments(args);
return fragment;
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = LayoutInflater.from(getContext()).inflate(R.layout.fra_item, container, false);
return view;
}
}
问题1：Caused by: java.lang.IllegalStateException: Fragment already added: MyDialogFragment
解决方法：不在onResume中直接调用show方法
public class MainActivity extends AppCompatActivity {
MyDialogFragment myDialogFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myDialogFragment=MyDialogFragment.newInstance();
}
@Override
protected void onResume() {
super.onResume();
myDialogFragment.show(getSupportFragmentManager(),"myDialogFragment");
}
}
问题2：java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
实现步骤：打开显示界面后，息屏或者按下home键
public class MainActivity extends AppCompatActivity {
// MyDialogFragment myDialogFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// myDialogFragment=MyDialogFragment.newInstance();
// myDialogFragment.show(getSupportFragmentManager(),"myDialogFragment");
MyDialogFragment myDialogFragment=MyDialogFragment.newInstance();
myDialogFragment.show(getSupportFragmentManager(),"myDialogFragment");
}
@Override
protected void onResume() {
super.onResume();
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.sendEmptyMessage(1);
}
}).start();
}
Handler handler=new Handler(){
@Override
public void handleMessage(@NonNull Message msg) {
super.handleMessage(msg);
MyDialogFragment myDialogFragment=MyDialogFragment.newInstance();
myDialogFragment.show(getSupportFragmentManager(),"myDialogFragment");
}
};
}
图片.png
解决方法：
getSupportFragmentManager().beginTransaction().add(myDialogFragment, "tag").commitAllowingStateLoss();代替show方法
public class MainActivity extends AppCompatActivity {
// MyDialogFragment myDialogFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MyDialogFragment myDialogFragment=MyDialogFragment.newInstance();
// myDialogFragment.show(getSupportFragmentManager(),"myDialogFragment");
getSupportFragmentManager().beginTransaction().add(myDialogFragment, "tag").commitAllowingStateLoss();
}
@Override
protected void onResume() {
super.onResume();
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.sendEmptyMessage(1);
}
}).start();
}
Handler handler=new Handler(){
@Override
public void handleMessage(@NonNull Message msg) {
super.handleMessage(msg);
MyDialogFragment myDialogFragment=MyDialogFragment.newInstance();
// myDialogFragment.show(getSupportFragmentManager(),"myDialogFragment");
getSupportFragmentManager().beginTransaction().add(myDialogFragment, "tag").commitAllowingStateLoss();
}
};
}
但是会出现新的问题：重复创建多个MyDialogFragment 对象，叠加在一起
改进方法：
public class MainActivity extends AppCompatActivity {
MyDialogFragment myDialogFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myDialogFragment=MyDialogFragment.newInstance();
// myDialogFragment.show(getSupportFragmentManager(),"myDialogFragment");
getSupportFragmentManager().beginTransaction().add(myDialogFragment, "tag").commitAllowingStateLoss();
}
@Override
protected void onResume() {
super.onResume();
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.sendEmptyMessage(1);
}
}).start();
}
Handler handler=new Handler(){
@Override
public void handleMessage(@NonNull Message msg) {
super.handleMessage(msg);
if (myDialogFragment==null){
myDialogFragment=MyDialogFragment.newInstance();
getSupportFragmentManager().beginTransaction().add(myDialogFragment, "tag").commitAllowingStateLoss();
}
}
};
}
新的问题：只会出现一次
改进的方法：
MyDialogFragment重写onDismiss
public class MyDialogFragment extends DialogFragment {
public static MyDialogFragment newInstance() {
Bundle args = new Bundle();
MyDialogFragment fragment = new MyDialogFragment();
fragment.setArguments(args);
return fragment;
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = LayoutInflater.from(getContext()).inflate(R.layout.fra_item, container, false);
return view;
}
@Override
public void onDismiss(@NonNull DialogInterface dialog) {
super.onDismiss(dialog);
final Activity activity = getActivity();
if (activity instanceof DialogInterface.OnDismissListener) {
((DialogInterface.OnDismissListener) activity).onDismiss(dialog);
}
}
}
public class MainActivity extends AppCompatActivity implements DialogInterface.OnDismissListener {
MyDialogFragment myDialogFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myDialogFragment=MyDialogFragment.newInstance();
// myDialogFragment.show(getSupportFragmentManager(),"myDialogFragment");
getSupportFragmentManager().beginTransaction().add(myDialogFragment, "tag").commitAllowingStateLoss();
}
@Override
protected void onResume() {
super.onResume();
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.sendEmptyMessage(1);
}
}).start();
}
Handler handler=new Handler(){
@Override
public void handleMessage(@NonNull Message msg) {
super.handleMessage(msg);
if (myDialogFragment==null){
myDialogFragment=MyDialogFragment.newInstance();
getSupportFragmentManager().beginTransaction().add(myDialogFragment, "tag").commitAllowingStateLoss();
}
// if(myDialogFragment!=null && myDialogFragment.getDialog()!=null
// && myDialogFragment.getDialog().isShowing()) {
// //dialog is showing so do something
//
// } else {
// //dialog is not showing
// myDialogFragment=MyDialogFragment.newInstance();
// getSupportFragmentManager().beginTransaction().add(myDialogFragment, "tag").commitAllowingStateLoss();
// }
}
};
@Override
public void onDismiss(DialogInterface dialog) {
myDialogFragment=null;
}
}
测试发现：
myDialogFragment.show(getSupportFragmentManager(),"myDialogFragment");也是可以的
参考： DialogFragment和onDismiss
https://www.cnblogs.com/yongfengnice/p/10403000.html
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