Android自定义View实现水平带数字百分比进度条

public class NumberProgressView extends View {
/**
* 进度条画笔的宽度（dp）
*/
private int paintProgressWidth = 3;
/**
* 文字百分比的字体大小（sp）
*/
private int paintTextSize = 20;
/**
* 左侧已完成进度条的颜色
*/
private int paintLeftColor = 0xff67aae4;
/**
* 右侧未完成进度条的颜色
*/
private int paintRightColor = 0xffaaaaaa;
/**
* 百分比文字的颜色
*/
private int paintTextColor = 0xffff0077;
/**
* Contxt
*/
private Context context;
/**
* 主线程传过来进程 0 - 100
*/
private int progress;
/**
* 得到自定义视图的宽度
*/
private int viewWidth;
/**
* 得到自定义视图的Y轴中心点
*/
private int viewCenterY;
/**
* 画左边已完成进度条的画笔
*/
private Paint paintleft = new Paint();
/**
* 画右边未完成进度条的画笔
*/
private Paint paintRight = new Paint();
/**
* 画中间的百分比文字的画笔
*/
private Paint paintText = new Paint();
/**
* 要画的文字的宽度
*/
private int textWidth;
/**
* 画文字时底部的坐标
*/
private float textBottomY;
/**
* 包裹文字的矩形
*/
private Rect rect = new Rect();
/**
* 文字总共移动的长度（即从0%到100%文字左侧移动的长度）
*/
private int totalMovedLength;
public NumberProgressView(Context context, AttributeSet attrs) {
super(context, attrs);
this.context = context;
// 构造器中初始化数据
initData();
}
/**
* 初始化数据
*/
private void initData() {
//设置进度条画笔的宽度
int paintProgressWidthPx = Utils.dip2px(context, paintProgressWidth);
//设置百分比文字的尺寸
int paintTextSizePx = Utils.sp2px(context, paintTextSize);
// 已完成进度条画笔的属性
paintleft.setColor(paintLeftColor);
paintleft.setStrokeWidth(paintProgressWidthPx);
paintleft.setAntiAlias(true);
paintleft.setStyle(Style.FILL);
// 未完成进度条画笔的属性
paintRight.setColor(paintRightColor);
paintRight.setStrokeWidth(paintProgressWidthPx);
paintRight.setAntiAlias(true);
paintRight.setStyle(Style.FILL);
// 百分比文字画笔的属性
paintText.setColor(paintTextColor);
paintText.setTextSize(paintTextSizePx);
paintText.setAntiAlias(true);
paintText.setTypeface(Typeface.DEFAULT_BOLD);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
getWidthAndHeight();
}
/**
* 得到视图等的高度宽度尺寸数据
*/
private void getWidthAndHeight() {
//得到包围文字的矩形的宽高
paintText.getTextBounds("000%", 0, "000%".length(), rect);
textWidth = rect.width();
textBottomY = viewCenterY + rect.height() / 2;
//得到自定义视图的高度
int viewHeight = getMeasuredHeight();
viewWidth = getMeasuredWidth();
viewCenterY = viewHeight / 2;
totalMovedLength = viewWidth - textWidth;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//得到float型进度
float progressFloat = progress / 100.0f;
//当前文字移动的长度
float currentMovedLentgh = totalMovedLength * progressFloat;
//画左侧已经完成的进度条，长度为从Veiw左端到文字的左侧
canvas.drawLine(0, viewCenterY, currentMovedLentgh, viewCenterY, paintleft);
//画右侧未完成的进度条，这个进度条的长度不是严格按照百分比来缩放的，因为文字的长度会变化，所以它的长度缩放比例也会变化
if (progress < 10) {
canvas.drawLine(currentMovedLentgh + textWidth * 0.5f, viewCenterY, viewWidth, viewCenterY, paintRight);
} else if (progress < 100) {
canvas.drawLine(currentMovedLentgh + textWidth * 0.75f, viewCenterY, viewWidth, viewCenterY, paintRight);
} else {
canvas.drawLine(currentMovedLentgh + textWidth, viewCenterY, viewWidth, viewCenterY, paintRight);
}
//画文字(注意：文字要最后画，因为文字和进度条可能会有重合部分，所以要最后画文字，用文字盖住重合的部分)
canvas.drawText(progress + "%", currentMovedLentgh, textBottomY, paintText);
}
/**
* @param progress 外部传进来的当前进度
*/
public void setProgress(int progress) {
this.progress = progress;
invalidate();
}
}

public class NumberProgressBarActivity extends Activity {
protected static final int WHAT_INCREASE = 1;
private NumberProgressView np_numberProgressBar;
private int progress;
private Handler handler = new Handler() {
public void handleMessage(android.os.Message msg) {
progress++;
np_numberProgressBar.setProgress(progress);
handler.sendEmptyMessageDelayed(WHAT_INCREASE, getRadomNumber(50, 200));
if (progress  = 100) {
handler.removeMessages(WHAT_INCREASE);
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_number_progress_bar);
np_numberProgressBar = (NumberProgressView) findViewById(R.id.np_numberProgressBar);
Button btn_numberProgressBar = (Button) findViewById(R.id.btn_numberProgressBar);
btn_numberProgressBar.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
increase();
}
});
}
private void increase() {
progress = 0;
np_numberProgressBar.setProgress(0);
handler.removeMessages(WHAT_INCREASE);
handler.sendEmptyMessage(WHAT_INCREASE);
}
/**
* 得到两个整数之间的一个随机数
*
* @param start 较小的数
* @param end  较大的数
* @return
*/
public int getRadomNumber(int start, int end) {
return (int) (start + Math.random() * (end - start));
}
}

/**
* 将dip或dp值转换为px值，保证尺寸大小不变
*/
public static int dip2px(Context context, float dipValue) {
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (dipValue * scale + 0.5f);
}
/**
* 将sp值转换为px值，保证文字大小不变
*/
public static int sp2px(Context context, float spValue) {
final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
return (int) (spValue * fontScale + 0.5f);
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" 
<com.example.viewdemo.view.NumberProgressView
android:id="@+id/np_numberProgressBar"
android:layout_width="wrap_content"
android:layout_height="100dp"
android:layout_margin="20dp"
android:background="#33890075"
/ 
<Button
android:id="@+id/btn_numberProgressBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="开始"/ 
</LinearLayout