listview imageview scrollview自定义效果

1,listview

[java] view
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public class MyListView extends ListView implements Runnable {

private float mLastDownY = 0f;

private int mDistance = 0;

private int mStep = 10;

private boolean mPositive = false;

public MyListView (Context context, AttributeSet attrs) {

super(context, attrs);

}

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

super(context, attrs, defStyle);

}

public MyListView (Context context) {

super(context);

}

@Override

public boolean onTouchEvent(MotionEvent event) {

switch (event.getAction()) {

case MotionEvent.ACTION_DOWN:

if (mLastDownY == 0f && mDistance == 0) {

mLastDownY = event.getY();

return true;

}

break;

case MotionEvent.ACTION_CANCEL:

break;

case MotionEvent.ACTION_UP:

if (mDistance != 0) {

mStep = 1;

mPositive = (mDistance >= 0);

this.post(this);

return true;

}

mLastDownY = 0f;

mDistance = 0;

break;

case MotionEvent.ACTION_MOVE:

if (mLastDownY != 0f) {

mDistance = (int) (mLastDownY - event.getY());

if ((mDistance < 0 && getFirstVisiblePosition() == 0 && getChildAt(0).getTop() == 0) || (mDistance > 0 && getLastVisiblePosition() == getCount() - 1)) {

mDistance /= 2;

scrollTo(0, mDistance);

return true;

}

}

mDistance = 0;

break;

}

return super.onTouchEvent(event);

}

public void run() {

mDistance += mDistance > 0 ? -mStep : mStep;

scrollTo(0, mDistance);

if ((mPositive && mDistance <= 0) || (!mPositive && mDistance >= 0)) {

scrollTo(0, 0);

mDistance = 0;

mLastDownY = 0f;

return;

}

mStep += 1;

this.postDelayed(this, 10);

}

}

2.scrollview

[java] view
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public class CustomScrollView extends ScrollView {

private View inner;// 孩子View

private float y;// 点击时y坐标

private Rect normal = new Rect();// 矩形(这里只是个形式，只是用于判断是否需要动画.)

private boolean isCount = false;// 是否开始计算

private boolean isMoveing = false;// 是否开始移动.

private ImageView imageView;

private int initTop, initbottom;// 初始高度

private int top, bottom;// 拖动时时高度。

public void setImageView(ImageView imageView) {

this.imageView = imageView;

}

public CustomScrollView(Context context, AttributeSet attrs) {

super(context, attrs);

}

/***

* 根据 XML 生成视图工作完成.该函数在生成视图的最后调用，在所有子视图添加完之后. 即使子类覆盖了 onFinishInflate

* 方法，也应该调用父类的方法，使该方法得以执行.

*/

@Override

protected void onFinishInflate() {

if (getChildCount() > 0) {

inner = getChildAt(0);

}

}

/** touch 事件处理 **/

@Override

public boolean onTouchEvent(MotionEvent ev) {

if (inner != null) {

commOnTouchEvent(ev);

}

return super.onTouchEvent(ev);

}

/***

* 触摸事件

*

* @param ev

*/

public void commOnTouchEvent(MotionEvent ev) {

int action = ev.getAction();

switch (action) {

case MotionEvent.ACTION_DOWN:

top = initTop = imageView.getTop();

bottom = initbottom = imageView.getBottom();

break;

case MotionEvent.ACTION_UP:

isMoveing = false;

// 手指松开.

if (isNeedAnimation()) {

animation();

}

break;

/***

* 排除出第一次移动计算，因为第一次无法得知y坐标， 在MotionEvent.ACTION_DOWN中获取不到，

* 因为此时是MyScrollView的touch事件传递到到了LIstView的孩子item上面.所以从第二次计算开始.

* 然而我们也要进行初始化，就是第一次移动的时候让滑动距离归0. 之后记录准确了就正常执行.

*/

case MotionEvent.ACTION_MOVE:

final float preY = y;// 按下时的y坐标

float nowY = ev.getY();// 时时y坐标

int deltaY = (int) (nowY - preY);// 滑动距离

if (!isCount) {

deltaY = 0; // 在这里要归0.

}

if (deltaY < 0 && top <= initTop)

return;

// 当滚动到最上或者最下时就不会再滚动，这时移动布局

isNeedMove();

if (isMoveing) {

// 初始化头部矩形

if (normal.isEmpty()) {

// 保存正常的布局位置

normal.set(inner.getLeft(), inner.getTop(),

inner.getRight(), inner.getBottom());

}

// 移动布局

inner.layout(inner.getLeft(), inner.getTop() + deltaY / 3,

inner.getRight(), inner.getBottom() + deltaY / 3);

top += (deltaY / 6);

bottom += (deltaY / 6);

imageView.layout(imageView.getLeft(), top,

imageView.getRight(), bottom);

}

isCount = true;

y = nowY;

break;

default:

break;

}

}

/***

* 回缩动画

*/

public void animation() {

TranslateAnimation taa = new TranslateAnimation(0, 0, top + 200,

initTop + 200);

taa.setDuration(200);

imageView.startAnimation(taa);

imageView.layout(imageView.getLeft(), initTop, imageView.getRight(),

initbottom);

// 开启移动动画

TranslateAnimation ta = new TranslateAnimation(0, 0, inner.getTop(),

normal.top);

ta.setDuration(200);

inner.startAnimation(ta);

// 设置回到正常的布局位置

inner.layout(normal.left, normal.top, normal.right, normal.bottom);

normal.setEmpty();

isCount = false;

y = 0;// 手指松开要归0.

}

// 是否需要开启动画

public boolean isNeedAnimation() {

return !normal.isEmpty();

}

/***

* 是否需要移动布局 inner.getMeasuredHeight():获取的是控件的总高度

*

* getHeight()：获取的是屏幕的高度

*

* @return

*/

public void isNeedMove() {

int offset = inner.getMeasuredHeight() - getHeight();

int scrollY = getScrollY();

// Log.e("jj", "scrolly=" + scrollY);

// 0是顶部，后面那个是底部

if (scrollY == 0 || scrollY == offset) {

isMoveing = true;

}

}

}

3. 保证长宽比 缩放使图片不失真的 imageview

[java] view
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public class RoundedImageView extends ImageView {

public RoundedImageView(Context context) {

super(context);

// TODO Auto-generated constructor stub

}

public RoundedImageView(Context context, AttributeSet attrs) {

super(context, attrs);

}

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

super(context, attrs, defStyle);

}

@Override

protected void onDraw(Canvas canvas) {

Drawable drawable = getDrawable();

if (drawable == null) {

return;

}

if (getWidth() == 0 || getHeight() == 0) {

return;

}

Bitmap b = ((BitmapDrawable) drawable).getBitmap();

Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);

int w = getWidth(), h = getHeight();

Bitmap roundBitmap = getCroppedBitmap(bitmap, w);

canvas.drawBitmap(roundBitmap, 0, 0, null);

}

public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) {

Bitmap sbmp;

if (bmp.getWidth() != radius || bmp.getHeight() != radius)

sbmp = Bitmap.createScaledBitmap(bmp, radius, radius, false);

else

sbmp = bmp;

Bitmap output = Bitmap.createBitmap(sbmp.getWidth(), sbmp.getHeight(),

Config.ARGB_8888);

Canvas canvas = new Canvas(output);

final int color = 0xffa19774;

final Paint paint = new Paint();

final Rect rect = new Rect(0, 0, sbmp.getWidth(), sbmp.getHeight());

paint.setAntiAlias(true);

paint.setFilterBitmap(true);

paint.setDither(true);

canvas.drawARGB(0, 0, 0, 0);

paint.setColor(Color.parseColor("#BAB399"));

canvas.drawCircle(sbmp.getWidth() / 2 + 0.7f,

sbmp.getHeight() / 2 + 0.7f, sbmp.getWidth() / 2 + 0.1f, paint);

paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));

canvas.drawBitmap(sbmp, rect, rect, paint);

return output;

}

}

比如 设置 imageview的 w，h

[html] view
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<com.example.view.RoundedImageView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="center_horizontal"

android:adjustViewBounds="true"

android:maxHeight="80dip"

android:maxWidth="80dip"

android:src="@drawable/aa" />