1.有些时候我们可能需要加载一些东西 下载东西 需要看到加载东西 下载东西界面 

2.首先 点击  进入 PorgressDialog使用界面 

 

3.

 

 4.当点击progressBar练习：弹出：

 

 5.当点击progressDialog练习： 弹出：

 

 

 

 

JAVA:

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class proActivity extends AppCompatActivity {
     private Button pro1,pro2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_pro);
        pro1=findViewById(R.id.pro1);
        pro2=findViewById(R.id.pro2);
        pro1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ProgressDialog progressDialog=new ProgressDialog(proActivity.this);
                progressDialog.setTitle("登陆中~~~");
                progressDialog.setMessage("正在登陆");
                progressDialog.setButton(DialogInterface.BUTTON_POSITIVE, "取消登陆", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        Toast.makeText(proActivity.this,"取消登陆",Toast.LENGTH_SHORT).show();
                    }
                });
                progressDialog.setOnCancelListener(new DialogInterface.OnCancelListener() {
                    @Override
                    public void onCancel(DialogInterface dialogInterface) {
                        Toast.makeText(proActivity.this,"加载完成",Toast.LENGTH_SHORT).show();
                    }
                });
                progressDialog.show();
            }
        });
        pro2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ProgressDialog progressDialog=new ProgressDialog(proActivity.this);
                progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
                progressDialog.setTitle("提示");
                progressDialog.setMessage("正在下载...");
                progressDialog.setButton(DialogInterface.BUTTON_POSITIVE, "继续下载", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {

                    }
                });
                progressDialog.setButton(DialogInterface.BUTTON_NEGATIVE, "取消下载", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {

                    }
                });
                progressDialog.show();
            }
        });
    }
}

　　XML：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="15dp"
    android:orientation="vertical"
    >
    <Button
        android:layout_marginTop="200dp"
        android:id="@+id/pro1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="progressBar练习"
        android:textAllCaps="false"
        />

    <Button
        android:layout_marginTop="200dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="progressDialog练习"
        android:textAllCaps="false"
        android:id="@+id/pro2"/>

</LinearLayout>