我想显示一个对话框/弹出窗口,向用户显示一条消息“您确定要删除此条目吗?”,其中一个按钮说“删除”。当点击Delete时,它应该删除该条目,否则什么都不删除。

我已经为这些按钮写了一个点击监听器,但我如何调用对话框或弹出窗口及其功能?


当前回答

我想补充David Hedlund的回答,分享一个比他发布的更有活力的方法,这样当你有消极行为要做的时候,你可以使用它,当你没有的时候,我希望它能有所帮助。

private void showAlertDialog(@NonNull Context context, @NonNull String alertDialogTitle, @NonNull String alertDialogMessage, @NonNull String positiveButtonText, @Nullable String negativeButtonText, @NonNull final int positiveAction, @Nullable final Integer negativeAction, @NonNull boolean hasNegativeAction)
{
    AlertDialog.Builder builder;
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        builder = new AlertDialog.Builder(context, android.R.style.Theme_Material_Dialog_Alert);
    } else {
        builder = new AlertDialog.Builder(context);
    }
    builder.setTitle(alertDialogTitle)
            .setMessage(alertDialogMessage)
            .setPositiveButton(positiveButtonText, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    switch (positiveAction)
                    {
                        case 1:
                            //TODO:Do your positive action here 
                            break;
                    }
                }
            });
            if(hasNegativeAction || negativeAction!=null || negativeButtonText!=null)
            {
            builder.setNegativeButton(negativeButtonText, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    switch (negativeAction)
                    {
                        case 1:
                            //TODO:Do your negative action here
                            break;
                        //TODO: add cases when needed
                    }
                }
            });
            }
            builder.setIcon(android.R.drawable.ic_dialog_alert);
            builder.show();
}

其他回答

   new AlertDialog.Builder(v.getContext()).setMessage("msg to display!").show();
    LayoutInflater inflater = LayoutInflater.from(HistoryActivity.this);
    final View vv = inflater.inflate(R.layout.dialog_processing_tts, null);
    final AlertDialog.Builder alert = new AlertDialog.Builder(
            HistoryActivity.this);
    alert.setTitle("Delete");
    alert.setView(vv);
    alert.setCancelable(false)
            .setPositiveButton("Delete", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    databaseHelperClass.deleteHistory(list.get(position).getID());
                    list.clear();
                    setAdapterForList();

                }
            })
            .setNegativeButton("Cancel",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int id) {
                            dialog.cancel();
                        }
                    });

    final AlertDialog dialog = alert.create();
    dialog.show();

现在与Jetpack撰写引入android,你可以简单地创建警报对话框使用下面的代码

if (viewModel.shouldDialogOpen.value) {

        AlertDialog(onDismissRequest = { viewModel.shouldDialogOpen.value = false },
            title = { Text("Delete Entry?") },
            text = {
                Text("Are you sure you want to delete this entry?")
            },
            dismissButton = {
                Button(modifier = Modifier.fillMaxWidth(), onClick = {
                    viewModel.shouldDialogOpen.value = false
                }) {
                    Text(text = "Cancel")
                }
            }, confirmButton = {
                Button(modifier = Modifier.fillMaxWidth(), onClick = {
                    viewModel.shouldDialogOpen.value = false
                    viewModel.beginDelete(recipe)
                }) {
                    Text(text = "Okay")
                }
            })
    }

在viewModel中。shouldDialogOpen, shouldDialogOpen是viewmodel中的一个mutablestate字段,当我们需要显示或解散对话框时,我们会改变它的值。

更多的代码样本Jetpack撰写:- https://androidlearnersite.wordpress.com/2021/08/03/jetpack-compose-1-0-0-sample-codes/

只是当你想解散对话框时要小心——使用dialog.dismiss()。在我的第一次尝试中,我使用了遣散dialog(0)(我可能从某个地方复制),有时它可以工作。使用系统提供的对象听起来是更安全的选择。

从列表中删除条目的代码

 /*--dialog for delete entry--*/
private void cancelBookingAlert() {
    AlertDialog dialog;
    final AlertDialog.Builder alertDialog = new AlertDialog.Builder(MainActivity.this, R.style.AlertDialogCustom);
    alertDialog.setTitle("Delete Entry");
    alertDialog.setMessage("Are you sure you want to delete this entry?");
    alertDialog.setCancelable(false);

    alertDialog.setPositiveButton("Delete", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
           //code to delete entry
        }
    });

    alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();
        }
    });

    dialog = alertDialog.create();
    dialog.show();
}

在删除按钮单击时调用上述方法