Android SeekBar(拖动条)

效果图

xml文件：

<?xml version="1.0" encoding="utf-8"?><LinearLayout android:layout_width="match_parent"    android:layout_height="match_parent"    xmlns:android="http://schemas.android.com/apk/res/android">    <!--max：设置进度条的最大值 progress：这是初始默认值-->        <SeekBar            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:max="255"            android:progress="255"            android:id="@+id/sb_main_seek"            />        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:id="@+id/tv_main_text"            android:layout_gravity="center"            />    </LinearLayout>

java代码：

package com.example.blogtest;import android.graphics.BitmapFactory;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.Gravity;import android.widget.CompoundButton;import android.widget.RatingBar;import android.widget.SeekBar;import android.widget.Switch;import android.widget.TextView;import android.widget.Toast;import android.widget.ToggleButton;public class MainActivity extends AppCompatActivity {    private TextView tv_main_text;    private SeekBar sb_main_seek;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //根据id获得SeekBar的控件        sb_main_seek = (SeekBar) findViewById(R.id.sb_main_seek);        tv_main_text = (TextView) findViewById(R.id.tv_main_text);        //设置SeekBar控件的监听        sb_main_seek.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener(){            @Override            //获取滑动过程的值            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {                tv_main_text.setText("当前的值为："+progress);            }            //开始滑动            @Override            public void onStartTrackingTouch(SeekBar seekBar) {            }            //结束滑动            @Override            public void onStopTrackingTouch(SeekBar seekBar) {            }        });    }}