SeekBar的简单使用

本篇文章主要是来学习UI控件中的seekbar拖动条使用，通常是伴随这视频或者音乐播放器一起使用的

SeekBar的基本用法

seekBar的基本属性

android:max="100" //滑动条的最大值

android:progress="60" //滑动条的当前值

android:secondaryProgress="70" //二级滑动条的进度

android:thumb = "@drawable/sb_icon" //滑块的drawable

SeekBar的三个方法

onProgressChanged：进度发生改变时会触发

onStartTrackingTouch：按住SeekBar时会触发

onStopTrackingTouch：放开SeekBar时触发

SeekBar的实现

布局文件的编写activity_main.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"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <SeekBar
        android:id="@+id/sb_nnrmal"
        android:layout_width="200dp"
        android:layout_height="40dp"

        android:layout_marginTop="100dp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/txt_cur"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</LinearLayout>

Activity逻辑 MainActivity

package com.example.seebar;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    private SeekBar sb_normal;
    private TextView txt_cur;
    private Context mcontext;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sb_normal = findViewById(R.id.sb_normal);
        txt_cur = findViewById(R.id.txt_cur);
        mcontext = MainActivity.this;
        bindViews();
    }

    private void bindViews() {
        sb_normal.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
                txt_cur.setText("当前进度值" + i + " /100");
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
                Toast.makeText(mcontext, "点击Seekbar", Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                Toast.makeText(mcontext, "释放SeekBar", Toast.LENGTH_SHORT).show();
            }
        });

    }

}

运行界面