Question

我遇到了DialogFragments的问题。我有一个Activity，它有一个按钮，onclick显示一个进度微调器（带自定义视图的DialogFragment），然后转到另一个活动。在我的第二个Activity中，我有button2，onclick将结果发送回我之前的活动，该活动应该关闭进度微调器。

public class MainActivity extends AppCompatActivity {

private Button button;
private int stackLevel;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    stackLevel=0;

    button = (Button)findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            showProgressDialog();

            Intent intent = new Intent(MainActivity.this,           SecondActivity.class);
            startActivityForResult(intent,2);
        }
    });


}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if(requestCode==2){

        dismissProgressDialog();

    }

}

public void showProgressDialog() {
    stackLevel++;

    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    Fragment prev = getSupportFragmentManager().findFragmentByTag("progressDialog");
    if (prev != null) {
        ft.remove(prev);
    }
    //ft.addToBackStack(null);
    // Create and show the dialog.
    DialogFragment newFragment = LoaderFragment.newInstance(stackLevel);
    //newFragment.show(ft,"progressDialog");
    ft.add(newFragment, "progressDialog");
    ft.commitAllowingStateLoss();
}


public void dismissProgressDialog() {

    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    DialogFragment prev = (DialogFragment) getSupportFragmentManager().findFragmentByTag("progressDialog");
    if (prev != null) {
        prev.dismiss();
    }
        ft.commitAllowingStateLoss();
}


 }

活动2

public class SecondActivity extends AppCompatActivity {

private Button button;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.second_layout);

    button = (Button)findViewById(R.id.button2);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            try {
                setResult(2);
            }catch (Exception e){

                e.printStackTrace();
            }


            finish();

        }
    });

}
}

但是当我关闭对话框片段

时，我收到了以下错误

    Caused by: java.lang.IllegalStateException: Can not perform this action     after onSaveInstanceState
 at android.support.v4.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:1527)
 at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1545)
 at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:654)
 at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:621)
 at android.support.v4.app.DialogFragment.dismissInternal(DialogFragment.java:201)
 at android.support.v4.app.DialogFragment.dismiss(DialogFragment.java:167)
 at com.example.am46517.samplefragmentapplication.MainActivity.dismissProgressDialog(MainActivity.java:70)
 at com.example.am46517.samplefragmentapplication.MainActivity.onActivityResult(MainActivity.java:42)
 at android.app.Activity.dispatchActivityResult(Activity.java:6926)
 at android.app.ActivityThread.deliverResults(ActivityThread.java:4293)
 at android.app.ActivityThread.handleSendResult(ActivityThread.java:4347) 
 at android.app.ActivityThread.-wrap20(ActivityThread.java)

Answer 1

在这种情况下，DialogFragment在后台被解散，因此，只有通过dismissAllowingStateLoss()方法完成后，才允许解散。但是要使用此方法，您只需要使用supportFragmentManager来显示此对话框，就像这样：（对不起，答案在Kotlin中）

gameLoadingDialog = GameLoadingDialog()
gameLoadingDialog?.show(supportFragmentManager, "gameLoadingDialog")

然后甚至可以在后台将其消除：

val prev = supportFragmentManager.findFragmentByTag("gameLoadingDialog")
if (prev != null && prev is GameLoadingDialog) {
    prev.dismissAllowingStateLoss()
}

Answer 2

我认为下面这行有问题; “无法解析符号LoaderFragment”。

DialogFragment newFragment = LoaderFragment.newInstance(stackLevel);

但是您可能遇到代码问题的原因可能与您实例化ProgressDialog有关。因为一旦您离开MainActivity，您就失去了本地声明。

之前我遇到过类似的问题，但之后想出了解决方法，因此：

创建父活动类...
public class CustomActivity extends AppCompatActivity
让MainAcvity.java and SecondActivity.java extend CustomActivity.java
将对话框方法 showProgressDialog（）和 dismissProgressDialog（）移动到 CustomActivity.java 中，然后在MainActivity.java或SecondActivity中调用它们.java（因为这两种方法都将成为继承CustomActivity的任何类的共享公共方法）

最后你的文件看起来应该是这样的......

<强> 1。 CustomActivity.java

public class CustomActivity extends AppCompatActivity {
private int stackLevel;
public void showProgressDialog ()
{
    stackLevel++;

    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    Fragment prev = getSupportFragmentManager().findFragmentByTag("progressDialog");
    if (prev != null) {
        ft.remove(prev);
    }
    //ft.addToBackStack(null);
    // Create and show the dialog.
    DialogFragment newFragment = LoaderFragment.newInstance(stackLevel);
    //newFragment.show(ft,"progressDialog");
    ft.add(newFragment, "progressDialog");
    ft.commitAllowingStateLoss();
}


public void dismissProgressDialog ()
{

    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    DialogFragment prev = (DialogFragment) getSupportFragmentManager().findFragmentByTag("progressDialog");
    if (prev != null) {
        prev.dismiss();
    }
    ft.commitAllowingStateLoss();
}}

<强> 2。 MainActivity.java

public class MainActivity extends CustomActivity {
@Override
protected void onCreate (Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Button button = (Button) findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick (View view)
        {
            showProgressDialog();

            Intent intent = new Intent(MainActivity.this, SecondActivity.class);
            startActivityForResult(intent, 2);
        }
    });
}

@Override
protected void onActivityResult (int requestCode, int resultCode, Intent data)
{
    if (requestCode == 2) {
        dismissProgressDialog();
    }
}}

第3。 SecondActivity.java

public class SecondActivity extends CustomActivity { @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.second_layout); Button button = (Button) findViewById(R.id.button2); button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { try { setResult(2); } catch (Exception e) { e.printStackTrace(); } finish(); } }); }}

尝试这个让我们看看它是否有效（我祈祷它确实; - ））

当Dialog片段被解除时，无法在onSaveInstanceState之后执行此操作

2 个答案: