继承进度条代码：
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.widget.ProgressBar;

public class PecentProgress extends ProgressBar {

    String text;
    Paint Paint;


    public PecentProgress(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
        System.out.println("1");
        initText();
    }

    public PecentProgress(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // TODO Auto-generated constructor stub
        System.out.println("2");
        initText();
    }


    public PecentProgress(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
        System.out.println("3");
        initText();
    }

    @Override
    public synchronized void setProgress(int progress) {
        // TODO Auto-generated method stub
        setText(progress);
        super.setProgress(progress);

    }

    @Override
    protected synchronized void onDraw(Canvas canvas) {
        // TODO Auto-generated method stub
        super.onDraw(canvas);
        //this.setText();
        Rect rect = new Rect();
        this.Paint.getTextBounds(this.text, 0, this.text.length(), rect);
        int x = (getWidth() / 2) - rect.centerX();
        int y = (getHeight() / 2) - rect.centerY();
        canvas.drawText(this.text, x, y, this.Paint);
    }

    //初始化
    private void initText(){
        this.Paint = new Paint();
        this.Paint.setColor(Color.BLUE);

    }

    private void setText(){
        setText(this.getProgress());
    }

    //设置文字内容
    private void setText(int progress){
        int i = (progress * 100)/this.getMax();
        this.text = String.valueOf(i) + "%";
    }



}

页面代码

<com.example.utils.PecentProgress 上面精度条继承类所在的包

android:id="@+id/load_proj_bar"
android:max="100"
android:layout_gravity="center"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_heightPercent="80%"      //安卓百分比
app:layout_widthPercent="90%"
style="@android:style/Widget.ProgressBar.Horizontal"
android:visibility="visible"

/>

//初始化

private PecentProgress progress = null;

pros = (PecentProgress ) findViewById(R.id.load_proj_bar);

//开启子线程，设置进度条

pros .setMax(100);
pros .setProgress(0);

安卓带百分比的进度条显示