本文实例为大家分享了Android实现图片加载进度提示的具体代码，供大家参考，具体内容如下

先上图：

实现原理：

第一个控件的实现原理是重写ImageView的onDraw()方法,利用Canvas的clipRect()方法控制图片的显示区域，主键扩大图片的显示区域，从而实现逐渐增加的效果

关键代码：

public class LoadingImageView extends ImageView {

/*** 背景图片 */

private Drawable bgDrawable;

/**前景图片*/

private Drawable fgDrawable;

/**是否显示加载进度条*/

private boolean isShowProgress;

private Resources rsc;

private int progress;

private int progressHeight;

private int progressLeft;

private int progressTop;

private int progressRight;

private int progressBottom;

public LoadingImageView(Context context) {

this(context,null);

}

public LoadingImageView(Context context, AttributeSet attrs) {

this(context, attrs,0);

}

public LoadingImageView(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

rsc = getResources();

}

@Override

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

super.onMeasure(widthMeasureSpec, heightMeasureSpec);

if(bgDrawable==null){

return;

}

progressLeft = getMeasuredWidth()/2-(fgDrawable.getIntrinsicWidth()/2);

progressTop = getMeasuredHeight()/2-(fgDrawable.getIntrinsicHeight()/2);

progressRight = getMeasuredWidth()/2+(fgDrawable.getIntrinsicWidth()/2);

progressBottom = getMeasuredHeight()/2+(fgDrawable.getIntrinsicHeight()/2);

}

@Override

public boolean onTouchEvent(MotionEvent event) {

return super.onTouchEvent(event);

}

/**

* 设置背景图片

* @param drawableRes

*/

public void setBgDrawableRes(int drawableRes){

bgDrawable = rsc.getDrawable(drawableRes);

invalidate();

}

public void setFgDrawableRes(int drawableRes){

fgDrawable = rsc.getDrawable(drawableRes);

invalidate();

}

public void setProgress(int progress,boolean flag) {

isShowProgress = flag;

if(progress>=0&progress<=100){

this.progress = progress;

invalidate();

}

}

@Override

protected void onDraw(Canvas canvas) {

if(bgDrawable!=null){

bgDrawable.setBounds(progressLeft, progressTop, progressRight, progressBottom);

bgDrawable.draw(canvas);

}

super.onDraw(canvas);

if(bgDrawable!=null&&isShowProgress){

bgDrawable.setBounds(progressLeft, progressTop, progressRight, progressBottom);

bgDrawable.draw(canvas);

}

if(fgDrawable!=null&&isShowProgress){

//根据进度计算图片显示的高的比

progressHeight = fgDrawable.getIntrinsicHeight()*progress/100;

//关键代码，设置图片的显示区域

canvas.clipRect(progressLeft,progressBottom-progressHeight,progressRight,progressBottom);

fgDrawable.setBounds(progressLeft, progressTop, progressRight, progressBottom);

fgDrawable.draw(canvas);

}

}

}

第二个圆形加载进度的原理其实也很简单，就是画弧线，不断增加弧线的角度，实现改变进度的功能

关键代码：

public class LoadingCircleView extends View {

private final Paint paint;

private final Context context;

private Resources res;

private int progress;

private int ringWidth;

//圆环的颜色

private int ringColor;

//进度条颜色

private int progressColor;

//字体颜色

private int textColor;

//字的大小

private int textSize;

private String textProgress;

public LoadingCircleView(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

this.context = context;

this.paint = new Paint();

this.res = context.getResources();

this.paint.setAntiAlias(true); //消除锯齿

this.ringWidth = dip2px(context, 10); //设置圆环宽度

this.ringColor = Color.rgb(233, 233, 233);

this.progressColor = Color.rgb(146, 206, 108);

this.textColor = Color.rgb(203, 203, 203);

this.textSize = 30;

}

public LoadingCircleView(Context context, AttributeSet attrs) {

this(context, attrs,0);

}

public LoadingCircleView(Context context) {

this(context,null);

}

/**

* 设置加载进度，取值范围在0~100之间

* @param progress

*/

public void setProgress(int progress) {

if(progress>=0&&progress<=100){

this.progress = progress;

invalidate();

}

}

/**

* 设置圆环背景色

* @param ringColor

*/

public void setRingColor(int ringColor) {

this.ringColor = res.getColor(ringColor);

}

/**

* 设置进度条颜色

* @param progressColor

*/

public void setProgressColor(int progressColor) {

this.progressColor = res.getColor(progressColor);

}

/**

* 设置字体颜色

* @param textColor

*/

public void setTextColor(int textColor) {

this.textColor = res.getColor(textColor);

}

/**

* 设置字体大小

* @param textSize

*/

public void setTextSize(int textSize) {

this.textSize = textSize;

}

/**

* 设置圆环半径

* @param ringWidth

*/

public void setRingWidthDip(int ringWidth) {

this.ringWidth = dip2px(context, ringWidth);

}

/**

* 通过不断画弧的方式更新界面，实现进度增加

*/

@Override

protected void onDraw(Canvas canvas) {

int center = getWidth()/2;

int radios = center-ringWidth/2;

//绘制圆环

this.paint.setStyle(Paint.Style.STROKE); //绘制空心圆

this.paint.setColor(ringColor);

this.paint.setStrokeWidth(ringWidth);

canvas.drawCircle(center,center, radios, this.paint);

RectF oval = new RectF(center-radios, center-radios, center+radios, center+radios);

this.paint.setColor(progressColor);

canvas.drawArc(oval, 90, 360*progress/100, false, paint);

this.paint.setStyle(Paint.Style.FILL);

this.paint.setColor(textColor);

this.paint.setStrokeWidth(0);

this.paint.setTextSize(textSize);

this.paint.setTypeface(Typeface.DEFAULT_BOLD);

textProgress = progress+"%";

float textWidth = paint.measureText(textProgress);

canvas.drawText(textProgress, center-textWidth/2, center+textSize/2, paint);

super.onDraw(canvas);

}

/**

* 根据手机的分辨率从 dp 的单位 转成为 px(像素)

*/

public static int dip2px(Context context, float dpValue) {

final float scale = context.getResources().getDisplayMetrics().density;

return (int) (dpValue * scale + 0.5f);

} }

控件定义好后就可以再Xml里面调用了：

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="vertical"

>

android:id="@+id/loading_image_view"

android:layout_width="258px"

android:layout_height="257px"

android:background="#330000"

>

android:id="@+id/loading_cirle_view"

android:layout_width="100dp"

android:layout_height="100dp"

>

最后就可以使用了,在主线程里面模拟加载进度，起一个线程，模仿加载进度逐渐增加：

public class MainActivity extends Activity {

ListView listview;

private LoadingImageView loadingImageView;

private LoadingCircleView loadingCircleView;

private Handler handler = new Handler(){

public void handleMessage(android.os.Message msg) {

loadingImageView.setProgress(msg.what,true);

loadingCircleView.setProgress(msg.what);

};

};

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

loadingImageView = (LoadingImageView) findViewById(R.id.loading_image_view);

loadingImageView.setFgDrawableRes(R.drawable.bg_click_load_img);

loadingImageView.setBgDrawableRes(R.drawable.ic_launcher);

loadingImageView.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

loading();

}

});

loadingCircleView = (LoadingCircleView) findViewById(R.id.loading_cirle_view);

loadingCircleView.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

loading();

}

});

// listview = (ListView) findViewById(R.id.listview);

// showImage();

}

private void loading(){

Thread t = new Thread(){

@Override

public void run() {

int i = 0;

while(i<=100){

try {

i++;

handler.sendEmptyMessage(i);

this.sleep(10);

} catch (InterruptedException e) {

e.printStackTrace();

}

}

super.run();

}

};

t.start();

}

@Override

protected void onResume() {

super.onResume();

}

@Override

protected void onPause() {

super.onPause();

}

@Override

protected void onDestroy() {

super.onDestroy();

}

}

好了，大工告成，可以运行了

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。