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/

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

Kotlin定制对话框: 如果你想创建自定义对话框

Dialog(activity!!, R.style.LoadingIndicatorDialogStyle)
        .apply {
            // requestWindowFeature(Window.FEATURE_NO_TITLE)
            setCancelable(true)
            setContentView(R.layout.define_your_custom_view_id_here)

            //access your custom view buttons/editText like below.z
            val createBt = findViewById<TextView>(R.id.clipboard_create_project)
            val cancelBt = findViewById<TextView>(R.id.clipboard_cancel_project)
            val clipboard_et = findViewById<TextView>(R.id.clipboard_et)
            val manualOption =
                findViewById<TextView>(R.id.clipboard_manual_add_project_option)

            //if you want to perform any operation on the button do like this

            createBt.setOnClickListener {
                //handle your button click here
                val enteredData = clipboard_et.text.toString()
                if (enteredData.isEmpty()) {
                    Utils.toast("Enter project details")
                } else {
                    navigateToAddProject(enteredData, true)
                    dismiss()
                }
            }

            cancelBt.setOnClickListener {
                dismiss()
            }
            manualOption.setOnClickListener {
                navigateToAddProject("", false)
                dismiss()
            }
            show()
        }

在style.xml中创建LoadingIndicatorDialogStyle

<style name="LoadingIndicatorDialogStyle" parent="Theme.AppCompat.Light.Dialog.Alert">
<item name="android:windowIsTranslucent">true</item>
<item name="android:windowBackground">@android:color/transparent</item>
<item name="android:windowContentOverlay">@null</item>
<item name="android:windowNoTitle">true</item>
<item name="android:statusBarColor">@color/black_transperant</item>
<item name="android:layout_gravity">center</item>
<item name="android:background">@android:color/transparent</item>
<!--<item name="android:windowAnimationStyle">@style/MaterialDialogSheetAnimation</item>-->

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

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();

你可以使用下面的代码:

AlertDialog.Builder alertDialog2 = new AlertDialog.Builder(
    AlertDialogActivity.this);

// Setting Dialog Title
alertDialog2.setTitle("Confirm Delete...");

// Setting Dialog Message
alertDialog2.setMessage("Are you sure you want delete this file?");

// Setting Icon to Dialog
alertDialog2.setIcon(R.drawable.delete);

// Setting Positive "Yes" Btn
alertDialog2.setPositiveButton("YES",
    new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
            // Write your code here to execute after dialog
            Toast.makeText(getApplicationContext(),
                           "You clicked on YES", Toast.LENGTH_SHORT)
                    .show();
        }
    });

// Setting Negative "NO" Btn
alertDialog2.setNegativeButton("NO",
    new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
            // Write your code here to execute after dialog
            Toast.makeText(getApplicationContext(),
                           "You clicked on NO", Toast.LENGTH_SHORT)
                    .show();
            dialog.cancel();
        }
    });

// Showing Alert Dialog
alertDialog2.show();