您可以简单地为progressbar设计一个xml接口，并将其作为一个视图传递给AlertDialog，然后在任何您需要的时候显示或关闭该对话框。

progress.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:padding="13dp"
    android:layout_centerHorizontal="true"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <ProgressBar
        android:id="@+id/loader"
        android:layout_marginEnd="5dp"
        android:layout_width="45dp"
        android:layout_height="45dp" />
    <TextView
        android:layout_width="wrap_content"
        android:text="Loading..."
        android:textAppearance="?android:textAppearanceSmall"
        android:layout_gravity="center_vertical"
        android:id="@+id/loading_msg"
        android:layout_toEndOf="@+id/loader"
        android:layout_height="wrap_content" />

</LinearLayout>

显示进度对话框的代码代码。只需复制这段代码并粘贴它的片段。

Dialog dialog;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setView(R.layout.progress);
        // This should be called once in your Fragment's onViewCreated() or in Activity onCreate() method to avoid dialog duplicates.
        dialog = builder.create();
    }
    
//   This method is used to control the progress dialog.
      private void setDialog(boolean show){
               if (show)dialog.show();
                    else dialog.dismiss();
           }

然后只要在你想要显示progressdialog时调用这个方法，并将true作为参数来显示它，或将false作为参数来取消对话框。

你可以使用AlertDialog作为ProgressDialog，参考下面的ProgressDialog代码。无论何时显示进度对话框，都需要调用此函数。

代码:

    public void setProgressDialog() {

    int llPadding = 30;
    LinearLayout ll = new LinearLayout(this);
    ll.setOrientation(LinearLayout.HORIZONTAL);
    ll.setPadding(llPadding, llPadding, llPadding, llPadding);
    ll.setGravity(Gravity.CENTER);
    LinearLayout.LayoutParams llParam = new LinearLayout.LayoutParams(
            LinearLayout.LayoutParams.WRAP_CONTENT,
            LinearLayout.LayoutParams.WRAP_CONTENT);
    llParam.gravity = Gravity.CENTER;
    ll.setLayoutParams(llParam);

    ProgressBar progressBar = new ProgressBar(this);
    progressBar.setIndeterminate(true);
    progressBar.setPadding(0, 0, llPadding, 0);
    progressBar.setLayoutParams(llParam);

    llParam = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
            ViewGroup.LayoutParams.WRAP_CONTENT);
    llParam.gravity = Gravity.CENTER;
    TextView tvText = new TextView(this);
    tvText.setText("Loading ...");
    tvText.setTextColor(Color.parseColor("#000000"));
    tvText.setTextSize(20);
    tvText.setLayoutParams(llParam);

    ll.addView(progressBar);
    ll.addView(tvText);

    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setCancelable(true);
    builder.setView(ll);

    AlertDialog dialog = builder.create();
    dialog.show();
    Window window = dialog.getWindow();
    if (window != null) {
        WindowManager.LayoutParams layoutParams = new WindowManager.LayoutParams();
        layoutParams.copyFrom(dialog.getWindow().getAttributes());
        layoutParams.width = LinearLayout.LayoutParams.WRAP_CONTENT;
        layoutParams.height = LinearLayout.LayoutParams.WRAP_CONTENT;
        dialog.getWindow().setAttributes(layoutParams);
    }
}

输出:

我使用来自https://github.com/Q115/DelayedProgressDialog的DelayedProgressDialog，它与ProgressDialog相同，在必要时具有延迟的额外好处。

使用它类似于Android O之前的ProgressDialog:

DelayedProgressDialog progressDialog = new DelayedProgressDialog();
progressDialog.show(getSupportFragmentManager(), "tag");

下面是@Han建议的ProgressDialog类的kotlin版本

class ProgressDialog(context: Context) : Dialog(context) {
init {
    val view = View.inflate(context, R.layout.progress_dialog, null)
    setContentView(view)
    setCancelable(false)
    window?.setBackgroundDrawable(
        ColorDrawable(Color.TRANSPARENT)
    )
}

}

下面是我的不确定进度对话框版本:

layout_loading_dialog.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="horizontal"
    android:padding="20dp">

    <ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="10dp"
        android:layout_marginRight="10dp"
        android:layout_weight="1" />

    <TextView
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="4"
        android:gravity="center"
        android:textAlignment="textStart"
        android:id="@+id/message"
        tools:text="Please wait..." />
</LinearLayout>

IndeterminateProgressDialog.kt:

class IndeterminateProgressDialog(context: Context) : AlertDialog(context) {
    private val messageTextView: TextView

    init {
        val view = LayoutInflater.from(context).inflate(R.layout.layout_loading_dialog, null)
        messageTextView = view.findViewById(R.id.message)
        setView(view)
    }

    override fun setMessage(message: CharSequence?) {
        this.messageTextView.text = message.toString()
    }

}

用法:

   val dialog = IndeterminateProgressDialog(context)
                    dialog.setMessage("Please wait...")
                    dialog.setCanceledOnTouchOutside(false)
                    dialog.setCancelable(false)
                    dialog.show()

也许这个指南可以帮助你。

通常我更喜欢用指示器制作自定义alertdialog。它解决了诸如自定义App视图等问题。