android自定义进度条图片,[Android自定义控件]带加载进度条的ImageView

很多时候图片上传的时候需要一个有加载效果的ImageView，其实实现起来也非常简单，下面是这个控件的demo

实现：

public class LoadingImgView extends ImageView{

private float per;

private boolean isfinished = false;

private String colorStr;

private Paint paintLayer;

private Paint textPaint;

private Rect textbound;

private float layer_w;

private float layer_h;

public LoadingImgView(Context context) {

super(context);

init();

}

public LoadingImgView(Context context, AttributeSet attrs) {

super(context, attrs);

init();

}

public LoadingImgView(Context context, AttributeSet attrs, int defStyleAttr) {

super(context, attrs, defStyleAttr);

init();

}

//初始化画笔

private void init(){

paintLayer = new Paint();

paintLayer.setColor(Color.LTGRAY);

paintLayer.setAlpha(100);

textPaint = new Paint();

textPaint.setColor(Color.DKGRAY);

textPaint.setTextSize(25);

textbound = new Rect();

}

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

if (isfinished)

return;

String perStr = (int) (per*100) + "%";

//获取文字区域的矩形大小，以便确定文字正中间的位置

textPaint.getTextBounds(perStr,0, perStr.length(),textbound);

layer_w = getWidth();

layer_h = getHeight()*per;

float y = getHeight() - layer_h;

//画遮蔽层

canvas.drawRect(0,y,layer_w,getHeight(),paintLayer);

//画文字

canvas.drawText(perStr, getWidth() / 2 - textbound.width() / 2, getHeight() / 2 + textbound.height() / 2, textPaint);

}

public void setPer(float per){

this.per = per;

//在主线程刷新

postInvalidate();

}

public void finish(){

isfinished = true;

postInvalidate();

}

}

其实也没什么要注意的地方，算是最简单的自定义控件之一了。有需要的可以改一改。