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

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

其他回答

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();

带有编辑文本的警报对话框

AlertDialog.Builder builder = new AlertDialog.Builder(context);//Context is activity context
final EditText input = new EditText(context);
builder.setTitle(getString(R.string.remove_item_dialog_title));
        builder.setMessage(getString(R.string.dialog_message_remove_item));
 builder.setTitle(getString(R.string.update_qty));
            builder.setMessage("");
            LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
                    LinearLayout.LayoutParams.MATCH_PARENT,
                    LinearLayout.LayoutParams.MATCH_PARENT);
            input.setLayoutParams(lp);
            input.setHint(getString(R.string.enter_qty));
            input.setTextColor(ContextCompat.getColor(context, R.color.textColor));
            input.setInputType(InputType.TYPE_CLASS_NUMBER);
            input.setText("String in edit text you want");
            builder.setView(input);
   builder.setPositiveButton(getString(android.R.string.ok),
                (dialog, which) -> {

//Positive button click event
  });

 builder.setNegativeButton(getString(android.R.string.cancel),
                (dialog, which) -> {
//Negative button click event
                });
        AlertDialog dialog = builder.create();
        dialog.show();
new AlertDialog.Builder(context)
    .setTitle("title")
    .setMessage("message")
    .setPositiveButton(android.R.string.ok, null)
    .show();

David Hedlund发布的代码给了我错误:

无法添加窗口-空令牌无效

如果你得到同样的错误,请使用下面的代码。它的工作原理!

runOnUiThread(new Runnable() {
    @Override
    public void run() {

        if (!isFinishing()){
            new AlertDialog.Builder(YourActivity.this)
              .setTitle("Your Alert")
              .setMessage("Your Message")
              .setCancelable(false)
              .setPositiveButton("ok", new OnClickListener() {
                  @Override
                  public void onClick(DialogInterface dialog, int which) {
                      // Whatever...
                  }
              }).show();
        }
    }
});

我在onClick方法中使用这个AlertDialog:

button.setOnClickListener(v -> {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    LayoutInflater layoutInflaterAndroid = LayoutInflater.from(this);
    View view = layoutInflaterAndroid.inflate(R.layout.cancel_dialog, null);
    builder.setView(view);
    builder.setCancelable(false);
    final AlertDialog alertDialog = builder.create();
    alertDialog.show();

    view.findViewById(R.id.yesButton).setOnClickListener(v -> onBackPressed());
    view.findViewById(R.id.nobutton).setOnClickListener(v -> alertDialog.dismiss());
});

dialog.xml

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<TextView
    android:id="@+id/textmain"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="5dp"
    android:gravity="center"
    android:padding="5dp"
    android:text="@string/warning"
    android:textColor="@android:color/black"
    android:textSize="18sp"
    android:textStyle="bold"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />


<TextView
    android:id="@+id/textpart2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="5dp"
    android:gravity="center"
    android:lines="2"
    android:maxLines="2"
    android:padding="5dp"
    android:singleLine="false"
    android:text="@string/dialog_cancel"
    android:textAlignment="center"
    android:textColor="@android:color/black"
    android:textSize="15sp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/textmain" />


<TextView
    android:id="@+id/yesButton"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginStart="40dp"
    android:layout_marginTop="5dp"
    android:layout_marginEnd="40dp"
    android:layout_marginBottom="5dp"
    android:background="#87cefa"
    android:gravity="center"
    android:padding="10dp"
    android:text="@string/yes"
    android:textAlignment="center"
    android:textColor="@android:color/black"
    android:textSize="15sp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/textpart2" />


<TextView
    android:id="@+id/nobutton"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginStart="40dp"
    android:layout_marginTop="5dp"
    android:layout_marginEnd="40dp"
    android:background="#87cefa"
    android:gravity="center"
    android:padding="10dp"
    android:text="@string/no"
    android:textAlignment="center"
    android:textColor="@android:color/black"
    android:textSize="15sp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/yesButton" />


<TextView
    android:layout_width="match_parent"
    android:layout_height="20dp"
    android:layout_margin="5dp"
    android:padding="10dp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/nobutton" />
</androidx.constraintlayout.widget.ConstraintLayout>