如何显示一个对话框以确认用户是否希望退出Android活动？

时间：2010-02-13 15:01:59

标签： android android-activity android-dialog activity-finish

我一直试图表明“你想退出吗？”用户尝试退出活动时的对话框类型。

但是我找不到合适的API挂钩。 Activity.onUserLeaveHint()最初看起来很有希望，但我找不到阻止活动完成的方法。

15 个答案:

答案 0 :(得分：386)

在Android 2.0+中，这看起来像：

@Override
public void onBackPressed() {
    new AlertDialog.Builder(this)
        .setIcon(android.R.drawable.ic_dialog_alert)
        .setTitle("Closing Activity")
        .setMessage("Are you sure you want to close this activity?")
        .setPositiveButton("Yes", new DialogInterface.OnClickListener()
    {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            finish();    
        }

    })
    .setNegativeButton("No", null)
    .show();
}

在早期版本中，它看起来像：

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    //Handle the back button
    if(keyCode == KeyEvent.KEYCODE_BACK) {
        //Ask the user if they want to quit
        new AlertDialog.Builder(this)
        .setIcon(android.R.drawable.ic_dialog_alert)
        .setTitle(R.string.quit)
        .setMessage(R.string.really_quit)
        .setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {

                //Stop the activity
                YourClass.this.finish();    
            }

        })
        .setNegativeButton(R.string.no, null)
        .show();

        return true;
    }
    else {
        return super.onKeyDown(keyCode, event);
    }

}

答案 1 :(得分：175)

@Override
public void onBackPressed() {
    new AlertDialog.Builder(this)
           .setMessage("Are you sure you want to exit?")
           .setCancelable(false)
           .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {
                   ExampleActivity.super.onBackPressed();
               }
           })
           .setNegativeButton("No", null)
           .show();
}

答案 2 :(得分：32)

修改了@ user919216代码..并使其与WebView兼容

@Override
public void onBackPressed() {
    if (webview.canGoBack()) {
        webview.goBack();

    }
    else
    {
     AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("Are you sure you want to exit?")
       .setCancelable(false)
       .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int id) {
                finish();
           }
       })
       .setNegativeButton("No", new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int id) {
                dialog.cancel();
           }
       });
AlertDialog alert = builder.create();
alert.show();
    }

}

答案 3 :(得分：22)

我更喜欢在后退按钮上双击而不是退出对话框退出。

在此解决方案中，它会在第一次返回时显示吐司，警告另一次按下将关闭应用程序。在这个例子中不到4秒。

private Toast toast;
private long lastBackPressTime = 0;

@Override
public void onBackPressed() {
  if (this.lastBackPressTime < System.currentTimeMillis() - 4000) {
    toast = Toast.makeText(this, "Press back again to close this app", 4000);
    toast.show();
    this.lastBackPressTime = System.currentTimeMillis();
  } else {
    if (toast != null) {
    toast.cancel();
  }
  super.onBackPressed();
 }
}

来自：http://www.androiduipatterns.com/2011/03/back-button-behavior.html

的令牌

答案 4 :(得分：20)

如果您不确定“back”的调用是否会退出应用程序，或者将用户带到另一个活动，您可以将上述答案包装在一个支票isTaskRoot（）中。如果您的主活动可以多次添加到后台堆栈，或者您正在操纵后台堆栈历史记录，则会发生这种情况。 

if(isTaskRoot()) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage("Are you sure you want to exit?")
       .setCancelable(false)
       .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int id) {
                YourActivity.super.onBackPressed;
           }
       })
       .setNegativeButton("No", new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int id) {
                dialog.cancel();
           }
       });
    AlertDialog alert = builder.create();
    alert.show();

} else {
    super.onBackPressed();
}

答案 5 :(得分：5)

使用Lambda：

    new AlertDialog.Builder(this).setMessage(getString(R.string.exit_msg))
        .setTitle(getString(R.string.info))
        .setPositiveButton(getString(R.string.yes), (arg0, arg1) -> {
            moveTaskToBack(true);
            finish();
        })
        .setNegativeButton(getString(R.string.no), (arg0, arg1) -> {
        })
        .show();

您还需要在gradle.build中设置级别语言以支持java 8：

compileOptions {
       targetCompatibility 1.8
       sourceCompatibility 1.8
}

答案 6 :(得分：5)

在中国，大多数应用程序将通过＆＃34;单击两次＆＃34;：

确认退出 
boolean doubleBackToExitPressedOnce = false;

@Override
public void onBackPressed() {
    if (doubleBackToExitPressedOnce) {
        super.onBackPressed();
        return;
    }

    this.doubleBackToExitPressedOnce = true;
    Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show();

    new Handler().postDelayed(new Runnable() {

        @Override
        public void run() {
            doubleBackToExitPressedOnce=false;                       
        }
    }, 2000);
}

答案 7 :(得分：5)

首先从super.onBackPressed();方法移除onbackPressed()代码而不是代码：

@Override
public void onBackPressed() {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage("Are you sure you want to exit?")
           .setCancelable(false)
           .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {
                    MyActivity.this.finish();
               }
           })
           .setNegativeButton("No", new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {
                    dialog.cancel();
               }
           });
    AlertDialog alert = builder.create();
    alert.show();

}

答案 8 :(得分：2)

我喜欢@GLee方法并将其与下面的片段一起使用。

@Override
public void onBackPressed() {
    if(isTaskRoot()) {
        new ExitDialogFragment().show(getSupportFragmentManager(), null);
    } else {
        super.onBackPressed();
    }
}

使用片段对话：

public class ExitDialogFragment extends DialogFragment {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        return new AlertDialog.Builder(getActivity())
            .setTitle(R.string.exit_question)
            .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    getActivity().finish();
                }
            })
            .setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    getDialog().cancel();
                }
            })
            .create();
    }
}

答案 9 :(得分：2)

Just put this code in your first activity 

@Override
    public void onBackPressed() {
        if (drawerLayout.isDrawerOpen(GravityCompat.END)) {
            drawerLayout.closeDrawer(GravityCompat.END);
        }
        else {
// if your using fragment then you can do this way
            int fragments = getSupportFragmentManager().getBackStackEntryCount();
            if (fragments == 1) {
new AlertDialog.Builder(this)
           .setMessage("Are you sure you want to exit?")
           .setCancelable(false)
           .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {
                    finish();
               }
           })
           .setNegativeButton("No", null)
           .show();


            } else {
                if (getFragmentManager().getBackStackEntryCount() > 1) {
                    getFragmentManager().popBackStack();
                } else {

           super.onBackPressed();
                }
            }
        }
    }

答案 10 :(得分：1)

这很好用

@Override
public void onBackPressed() {
    if (mExitOnBackPress) finish();
    else {
        Toast.makeText(this, R.string.msg_confirm_exit, Toast.LENGTH_SHORT).show();
        mExitOnBackPress = true;
        new android.os.Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                mExitOnBackPress = false;
            }
        }, 2000);
    }
}

答案 11 :(得分：1)

另一个替代方案是在第一个背面按下时显示Toast / Snackbar，要求再次按回退出，这比显示的更少干扰AlertDialog确认用户是否要退出该应用。

您可以使用DoubleBackPress Android Library通过几行代码实现此目的。 Example GIF showing similar behaviour.

首先，将依赖项添加到您的应用程序：

dependencies {
    implementation 'com.github.kaushikthedeveloper:double-back-press:0.0.1'
}

接下来，在您的Activity中，实现所需的行为。

// set the Toast to be shown on FirstBackPress (ToastDisplay - builtin template)
// can be replaced by custom action (new FirstBackPressAction{...})
FirstBackPressAction firstBackPressAction = new ToastDisplay().standard(this);

// set the Action on DoubleBackPress
DoubleBackPressAction doubleBackPressAction = new DoubleBackPressAction() {
    @Override
    public void actionCall() {
        // TODO : Exit the application
        finish();
        System.exit(0);
    }
};

// setup DoubleBackPress behaviour : close the current Activity
DoubleBackPress doubleBackPress = new DoubleBackPress()
        .withDoublePressDuration(3000)     // msec - wait for second back press
        .withFirstBackPressAction(firstBackPressAction)
        .withDoubleBackPressAction(doubleBackPressAction);

最后，将此设置为背面按下的行为。

@Override
public void onBackPressed() {
    doubleBackPress.onBackPressed();
}

答案 12 :(得分：0)

如果您使用片段而不是活动，请将此代码放入您的主要活动中

    private Toast toast;
    private long lastBackPressTime = 0;
    @SuppressLint("WrongConstant")
    @Override
    public void onBackPressed() {
        int fragments = getFragmentManager().getBackStackEntryCount();
        if (fragments == 0) {
            // make layout invisible since last fragment will be removed
            if (this.lastBackPressTime < System.currentTimeMillis() - 3000) {
                toast = Toast.makeText(this, "Press back again to close this app", 3000);
                toast.show();
                this.lastBackPressTime = System.currentTimeMillis();

            }else{
                if (toast != null) {
                    toast.cancel();
                }
                super.onBackPressed();
            }

        }else{
            if (toast != null) {
                toast.cancel();
            }
            super.onBackPressed();
        }
    }

答案 13 :(得分：0)

显示对话框以确认用户希望退出Android活动。

将以下代码添加到onBackPressed重写方法。

@Override
        public void onBackPressed() {

                hideViews();
                getSupportActionBar().setDisplayHomeAsUpEnabled(false);

                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setMessage("Are you sure you want to exit the activity?")
                        .setCancelable(false)
                        .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                                    finishAffinity();
                                }
                            }
                        })
                        .setNegativeButton("No", new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                dialog.cancel();
                            }
                        });
                AlertDialog alert = builder.create();
                alert.show();

        }

希望对您有帮助。

答案 14 :(得分：0)

如果您在应用程序中使用片段。.这是解决方法

Coach.hasOne(Team)  // `coachId` will be added on Team / Target model
相关问题
最新问题