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

为Kotln开发人员提供最简单的解决方案

val alertDialogBuilder: AlertDialog.Builder = AlertDialog.Builder(requireContext())
    alertDialogBuilder.setMessage(msg)
    alertDialogBuilder.setCancelable(true)

    alertDialogBuilder.setPositiveButton(
        getString(android.R.string.ok)
    ) { dialog, _ ->
        dialog.cancel()
    }

    val alertDialog: AlertDialog = alertDialogBuilder.create()
    alertDialog.show()

其他回答

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();
}
showDialog(MainActivity.this, "title", "message", "OK", "Cancel", {...}, {...});

科特林

fun showDialog(context: Context, title: String, msg: String,
               positiveBtnText: String, negativeBtnText: String?,
               positiveBtnClickListener: DialogInterface.OnClickListener,
               negativeBtnClickListener: DialogInterface.OnClickListener?): AlertDialog {
    val builder = AlertDialog.Builder(context)
            .setTitle(title)
            .setMessage(msg)
            .setCancelable(true)
            .setPositiveButton(positiveBtnText, positiveBtnClickListener)
    if (negativeBtnText != null)
        builder.setNegativeButton(negativeBtnText, negativeBtnClickListener)
    val alert = builder.create()
    alert.show()
    return alert
}

Java

public static AlertDialog showDialog(@NonNull Context context, @NonNull String title, @NonNull String msg,
                                     @NonNull String positiveBtnText, @Nullable String negativeBtnText,
                                     @NonNull DialogInterface.OnClickListener positiveBtnClickListener,
                                     @Nullable DialogInterface.OnClickListener negativeBtnClickListener) {
    AlertDialog.Builder builder = new AlertDialog.Builder(context)
            .setTitle(title)
            .setMessage(msg)
            .setCancelable(true)
            .setPositiveButton(positiveBtnText, positiveBtnClickListener);
    if (negativeBtnText != null)
        builder.setNegativeButton(negativeBtnText, negativeBtnClickListener);
    AlertDialog alert = builder.create();
    alert.show();
    return alert;
}

您可以为此使用AlertDialog,并使用它的Builder类构造一个AlertDialog。下面的例子使用默认的构造函数,它只接受Context,因为对话框将从传入的Context继承适当的主题,但是如果你想这样做,还有一个构造函数允许你指定一个特定的主题资源作为第二个参数。

new AlertDialog.Builder(context)
    .setTitle("Delete entry")
    .setMessage("Are you sure you want to delete this entry?")

    // Specifying a listener allows you to take an action before dismissing the dialog.
    // The dialog is automatically dismissed when a dialog button is clicked.
    .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) { 
            // Continue with delete operation
        }
     })

    // A null listener allows the button to dismiss the dialog and take no further action.
    .setNegativeButton(android.R.string.no, null)
    .setIcon(android.R.drawable.ic_dialog_alert)
    .show();

现在最好使用DialogFragment而不是直接创建AlertDialog。

怎么做?参见:https://stackoverflow.com/a/21032871/1390874 为什么?参见:https://stackoverflow.com/a/13765411/1390874

你也可以尝试这种方式,它将为你提供材料样式的对话框

private void showDialog()
{
    String text2 = "<font color=#212121>Medi Notification</font>";//for custom title color

    AlertDialog.Builder builder = new AlertDialog.Builder(this, R.style.AppCompatAlertDialogStyle);
    builder.setTitle(Html.fromHtml(text2));

    String text3 = "<font color=#A4A4A4>You can complete your profile now or start using the app and come back later</font>";//for custom message
    builder.setMessage(Html.fromHtml(text3));

    builder.setPositiveButton("DELETE", new DialogInterface.OnClickListener()
    {
        @Override
        public void onClick(DialogInterface dialog, int which)
        {
            toast = Toast.makeText(getApplicationContext(), "DELETE", Toast.LENGTH_SHORT);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();              
        }
    });

    builder.setNegativeButton("CANCEL", new DialogInterface.OnClickListener()
    {
        @Override
        public void onClick(DialogInterface dialog, int which)
        {
            toast = Toast.makeText(getApplicationContext(), "CANCEL", Toast.LENGTH_SHORT);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();
        }
    });
    builder.show();
}