入门篇：动态进度条ProgressBar的实现

October 25, 2019

377views

1628字数

**目的：**做一个包含进度条控件的App，要求用Java代码实现进度条的动态效果。

**方法简介：**界面使用了RelativeLayout布局，其中嵌套了一个ProgressBar控件、一个TextView控件和一个Button控件。
使用线程模拟文件上传进度，目的是实现点击上传按钮ProgressBar进行不断增长，TextView会显示当前进度所占百分比，当上传实现100%之后会弹出“上传完成!”的Toast。

**动态进度条实现：**
activity_mian.xml:
```xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

<Button
            android:id="@+id/button"
            android:layout_below="@+id/textView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="30dp"
            android:text="上传" />
    </RelativeLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
```
MainActivity.java:
```java
package com.example.progressbar;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {
    private ProgressBar mpgbar;
    private Button mbt;
    private Handler handler;
    private TextView mTextView;

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

mpgbar = findViewById(R.id.pgBar);
        mbt = findViewById(R.id.button);
        mTextView = findViewById((R.id.textView));
        handler = new MyHandler();

final int pg;
        pg = 50;
        mbt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Thread me = new Thread(new mthread());
                me.start();
            }
        });
    }

class mthread implements Runnable {
        int i = 1;

@Override
        public void run() {
            while (i <= 100) {
                Message message = Message.obtain();
                message.arg1 = i;
                handler.sendMessage(message);

mpgbar.setProgress(i);
                i++;
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }

class MyHandler extends Handler {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            int arg1 = msg.arg1;
            mTextView.setText("当前上传进度为：" + arg1 + "%");
            if (arg1 == 100) {
                Toast.makeText(MainActivity.this, "上传完成!", Toast.LENGTH_SHORT).show();
            }
        }
    }
}
```

Last modification：April 20th, 2020 at 11:18 am

如果觉得对你有用，请随意赞赏

入门篇：动态进度条ProgressBar的实现

wloveyang • 2019 年 10 月 25 日

Leave a Comment Cancel reply

入门篇：动态进度条ProgressBar的实现