實現SeekBar.OnSeekBarChangeListener介面 對事件進行監聽

xml檔案：

<?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:orientation="vertical">

  <SeekBar
      android:id="@+id/seekBar"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:max="100"
      android:progress="50" />

  <TextView
      android:id="@+id/tv1"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
       />

  <TextView
      android:id="@+id/tv2"
      android:layout_width="match_parent"
      android:layout_height="wrap_content" />

</LinearLayout>
 

package com.example.lenovo.seekbar;

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.SeekBar;
import android.widget.TextView;

public class MainActivity extends Activity implements SeekBar.OnSeekBarChangeListener {

    private SeekBar seekBar;
    private TextView tv1;
    private TextView tv2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv1=findViewById(R.id.tv1);
        tv2=findViewById(R.id.tv2);
        seekBar=findViewById(R.id.seekBar);
        //設定監聽器 監聽數值改變情況
        seekBar.setOnSeekBarChangeListener(this);
    }
    //數值改變
    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        tv1.setText("正在拖動");
        tv2.setText("當前數值："+progress);
    }
    //開始拖動
    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {
        tv1.setText("開始拖動");
    }
    //停止拖動
    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {
        tv1.setText("停止拖動");
    }
}