UI界面和组件（三）

ProgressBar组件

一、圆形进度条

<ProgressBar
        android:id="@+id/progressbar1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
    <TextView
        android:text="正在加载中..."
        android:textSize="18sp"
        android:textStyle="bold"
        android:gravity="center_horizontal"

        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

二、水平进度条

 <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <ProgressBar
            android:id="@+id/progressbar2"
            style="@style/Widget.AppCompat.ProgressBar.Horizontal"
            android:progress="50"
            android:padding="30dp"

            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
        <SeekBar
            android:id="@+id/seekbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
        <TextView
            android:id="@+id/tv_progress"
            android:textSize="16sp"
            android:gravity="center_horizontal"
            android:text="当前进度是： "

            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>

    </LinearLayout>

package com.androidstudy.uicomponenttest;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.SeekBar;
import android.widget.TextView;

public class ProgressActivity extends AppCompatActivity {
    private ProgressBar pbHorizontal;
    private SeekBar seekBar;
    private TextView tvProgress;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_progress);
        initView();
    }
    public void initView(){
        pbHorizontal = findViewById(R.id.progressbar2);
        seekBar = findViewById(R.id.seekbar);
        tvProgress = findViewById(R.id.tv_progress);

        //捕捉seekbar
        seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                pbHorizontal.setProgress(progress);
                tvProgress.setText("当前进度为： "+ progress+"%");
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) { //鼠标碰到seekBar瞬间触发

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {  // 鼠标松开时，触发
                if(pbHorizontal.getProgress() >= pbHorizontal.getMax()){
                    pbHorizontal.setVisibility(View.INVISIBLE);//不可见，但是占用空间  GONE不可见 也不占用空间
                }else {
                    pbHorizontal.setVisibility(View.VISIBLE);
                }
            }
        });

    }
}

三、自动进度条模拟

xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical">

    <TextView
        android:id="@+id/tv_main_progress"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        android:gravity="center_horizontal" />

    <ProgressBar
        android:id="@+id/pb_main_progress"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:max="100"
        style="@style/Widget.AppCompat.ProgressBar.Horizontal"

        android:padding="5dp"
        android:progress="30" />

    <SeekBar
        android:id="@+id/sb_main"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="30dp" />

    <Button
        android:id="@+id/btn_main_download"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"

        android:layout_marginTop="30dp"
        android:text="下载" />

</LinearLayout>

java

package com.androidstudy.progressauto;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

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.SeekBar;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private ProgressBar progressBar;
    private SeekBar seekBar;
    private Button btnDownload;
    private Handler handler;
    private int progress = 0;//进度条进度
    private TextView tvProgress;

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

        tvProgress = this.findViewById(R.id.tv_main_progress);

        progressBar = this.findViewById(R.id.pb_main_progress);

        seekBar = this.findViewById(R.id.sb_main);

        seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                progressBar.setProgress(progress);//设置进度条 = 滑杆进度
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {

            }
        });

        btnDownload = this.findViewById(R.id.btn_main_download);

        handler = new Handler(){
            @Override
            public void handleMessage(@NonNull Message msg) {
                super.handleMessage(msg);
                switch (msg.what){
                    case 1:
                        if(progress<= 100) {
                            progressBar.setProgress(progress);
                            tvProgress.setText(progress + "%");
                            progress++;

                            handler.sendEmptyMessageDelayed(1, 200);//间隔200ms
                        }else{
                            Toast.makeText(MainActivity.this,"下载完成",Toast.LENGTH_SHORT).show();
                        }break;
                }
            }
        };
        btnDownload.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                //整一个多线程******************************************************
                Thread thread = new Thread(new Runnable() {
                    @Override
                    public void run() {
                        //向主线程发送消息，让主线程。。。
                        //handler用于传递消息
                        handler.sendEmptyMessage(1);
                    }
                });
                thread.start();



            }
        });

    }
}