Android:滚动Imageview

xurqigkl  于 2023-06-28  发布在  Android
关注(0)|答案(9)|浏览(110)

我有一个ImageView,它的高度是正常屏幕的两倍(960倾角)。我想滚动它很好地向上和向下在屏幕上。屏幕底部应包含一个按钮。我尝试了ScrollView和ImageView的各种组合,但没有任何成功。我也考虑过:isScrollContainer属性,但没有结果。有人知道怎么做吗?干杯,卢卡

uxhixvfz

uxhixvfz1#

@cV2非常感谢你的代码。它让我朝着我需要的方向前进。这是我修改后的版本,它在图像的边缘停止滚动...

// set maximum scroll amount (based on center of image)
    int maxX = (int)((bitmapWidth / 2) - (screenWidth / 2));
    int maxY = (int)((bitmapHeight / 2) - (screenHeight / 2));

    // set scroll limits
    final int maxLeft = (maxX * -1);
    final int maxRight = maxX;
    final int maxTop = (maxY * -1);
    final int maxBottom = maxY;

    // set touchlistener
    ImageView_BitmapView.setOnTouchListener(new View.OnTouchListener()
    {
        float downX, downY;
        int totalX, totalY;
        int scrollByX, scrollByY;
        public boolean onTouch(View view, MotionEvent event)
        {
            float currentX, currentY;
            switch (event.getAction())
            {
                case MotionEvent.ACTION_DOWN:
                    downX = event.getX();
                    downY = event.getY();
                    break;

                case MotionEvent.ACTION_MOVE:
                    currentX = event.getX();
                    currentY = event.getY();
                    scrollByX = (int)(downX - currentX);
                    scrollByY = (int)(downY - currentY);

                    // scrolling to left side of image (pic moving to the right)
                    if (currentX > downX)
                    {
                        if (totalX == maxLeft)
                        {
                            scrollByX = 0;
                        }
                        if (totalX > maxLeft)
                        {
                            totalX = totalX + scrollByX;
                        }
                        if (totalX < maxLeft)
                        {
                            scrollByX = maxLeft - (totalX - scrollByX);
                            totalX = maxLeft;
                        }
                    }

                    // scrolling to right side of image (pic moving to the left)
                    if (currentX < downX)
                    {
                        if (totalX == maxRight)
                        {
                            scrollByX = 0;
                        }
                        if (totalX < maxRight)
                        {
                            totalX = totalX + scrollByX;
                        }
                        if (totalX > maxRight)
                        {
                            scrollByX = maxRight - (totalX - scrollByX);
                            totalX = maxRight;
                        }
                    }

                    // scrolling to top of image (pic moving to the bottom)
                    if (currentY > downY)
                    {
                        if (totalY == maxTop)
                        {
                            scrollByY = 0;
                        }
                        if (totalY > maxTop)
                        {
                            totalY = totalY + scrollByY;
                        }
                        if (totalY < maxTop)
                        {
                            scrollByY = maxTop - (totalY - scrollByY);
                            totalY = maxTop;
                        }
                    }

                    // scrolling to bottom of image (pic moving to the top)
                    if (currentY < downY)
                    {
                        if (totalY == maxBottom)
                        {
                            scrollByY = 0;
                        }
                        if (totalY < maxBottom)
                        {
                            totalY = totalY + scrollByY;
                        }
                        if (totalY > maxBottom)
                        {
                            scrollByY = maxBottom - (totalY - scrollByY);
                            totalY = maxBottom;
                        }
                    }

                    ImageView_BitmapView.scrollBy(scrollByX, scrollByY);
                    downX = currentX;
                    downY = currentY;
                    break;

            }

            return true;
        }
    });

我相信它可以改进一点,但它工作得很好。:)

9vw9lbht

9vw9lbht2#

我搜索了很久才找到这段代码,所以我想分享这段伟大的代码:
此代码来自Activity,该Activity在后端有一个xml文件**,其中包含名为'img'的ImageView**

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/img"
    android:scaleType="center"
    android:background="#fff"
    android:src="@drawable/picName"
/>
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.xml_name_layout);

    final ImageView switcherView = (ImageView) this.findViewById(R.id.img);

    switcherView.setOnTouchListener(new View.OnTouchListener() {

        public boolean onTouch(View arg0, MotionEvent event) {

            float curX, curY;

            switch (event.getAction()) {

                case MotionEvent.ACTION_DOWN:
                    mx = event.getX();
                    my = event.getY();
                    break;
                case MotionEvent.ACTION_MOVE:
                    curX = event.getX();
                    curY = event.getY();
                    switcherView.scrollBy((int) (mx - curX), (int) (my - curY));
                    mx = curX;
                    my = curY;
                    break;
                case MotionEvent.ACTION_UP:
                    curX = event.getX();
                    curY = event.getY();
                    switcherView.scrollBy((int) (mx - curX), (int) (my - curY));
                    break;
            }

            return true;
        }
    });

}

把工作做得很完美包括水平和垂直滚动(已启用)
只有消极的一面...你可以滚动图片的边缘但这对我来说不是问题。花点时间你就可以很容易地实现这个功能:)
祝你好运&&玩得开心

hk8txs48

hk8txs483#

这就是我的方法:p

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:scrollbarAlwaysDrawVerticalTrack="true">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:adjustViewBounds="true"
        android:contentDescription="Specs"
        android:scrollbars="vertical"
        android:src="@drawable/image"/>
</ScrollView>
fxnxkyjh

fxnxkyjh4#

@wirbly非常感谢你的代码,它完全按照我想要的方式工作。但是当我第一次读你的代码时,我对你忘记定义的四个变量有点困惑。
所以,我想添加代码的定义,使其更清晰。

Resources res=getResources();
Bitmap mBitmap = BitmapFactory.decodeResource(res, R.drawable.p_1920x1080); 
BitmapDrawable bDrawable = new BitmapDrawable(res, mBitmap);

//get the size of the image and  the screen
int bitmapWidth = bDrawable.getIntrinsicWidth();
int bitmapHeight = bDrawable.getIntrinsicHeight();
int screenWidth = this.getWindowManager().getDefaultDisplay().getWidth();  
int screenHeight = this.getWindowManager().getDefaultDisplay().getHeight();

希望能帮上忙

wooyq4lh

wooyq4lh5#

最简单的方法是imho使用webview并通过本地html文件将图像加载到其中。这样,如果您想使用缩放控件,您也将自动获得它们。对于大图像(即如果它是1000或3000像素宽),你会注意到,Android(Coliris)是不是很擅长显示大缩放图像非常清晰,即使原始图像是清晰和未压缩)。这是一个已知问题。解决这个问题的方法是将大图片分解成小块,然后通过html(div或table)将它们重新组合在一起。我使用这种方法向用户提供地铁Map(比屏幕大并且可滚动)。

WebView webView = (WebView)findViewById(R.id.webView);
    webView.getSettings().setBuiltInZoomControls(true);
    webView.getSettings().setUseWideViewPort(true);
    webView.getSettings().setDefaultZoom(WebSettings.ZoomDensity.FAR);

    webView.loadUrl( "content://com.myapp.android.localfile/sdcard/myappdata/common/mtr_map.html");

这可能适用于大多数情况/“常规应用程序”,但取决于您的特定情况。如果你正在谈论一个图像作为一个游戏的可滚动背景,它可能对你没有用。
除了html文件,你也可以直接加载图片(png,jpg)。如果你不想要缩放控制,只要把它们关掉。

eivgtgni

eivgtgni6#

另一种方法是创建HorizontalScrollView,将imageView添加到其中,然后将HorizontalScrollView添加到ScrollView中。这允许您向上、向下、向左、向右滚动。

ymzxtsji

ymzxtsji7#

对我很有效

<ScrollView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="10dp">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:src="@drawable/img"
            android:scaleType="centerCrop"
            android:adjustViewBounds="true"/>

        <Button
            style="@style/btn"
            android:id="@+id/btn"
            android:layout_height="60dp"
            android:layout_marginTop="20dp"
            android:background="@drawable/btn"
            android:onClick="click"
            android:text="text" />
    </LinearLayout>

</ScrollView>
cwxwcias

cwxwcias8#

嘿,伙计们,找到了一个简单和100%可靠的解决方案,正如上面提到的X先生(因为提到的其他代码在某些设备上不起作用或破坏)只需使用Android提供的ScrollView,它就可以处理事情了
像这样的东西

<ScrollView android:layout_width="fill_parent" android:id="@+id/scrollView1"
        android:layout_height="wrap_content" android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true" android:layout_above="@+id/button1"
        android:layout_alignParentRight="true" android:scrollbarAlwaysDrawVerticalTrack="true">
        <LinearLayout android:id="@+id/linearLayout1"
            android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center_horizontal">
            <ImageView android:src="@android:drawable/ic_menu_report_image"
                android:layout_height="wrap_content" android:id="@+id/imageView1"
                android:layout_width="wrap_content"></ImageView>
        </LinearLayout>
    </ScrollView>

and in oncreate创建something like this

if (mImageName != null) {
        InputStream is = null;
        try {
            is = this.getResources().getAssets().open("mathematics/"+mImageName);
        } catch (IOException e) {
        }
        Bitmap image = BitmapFactory.decodeStream(is);

        mImageView.setImageBitmap(image);
}

干杯!

qni6mghb

qni6mghb9#

为ZoomableImageView创建一个JavaClass,其名称为:

import android.content.Context;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;

public class ZoomableImageView extends androidx.appcompat.widget.AppCompatImageView implements ScaleGestureDetector.OnScaleGestureListener {
    private Matrix matrix;
    private float scaleFactor = 1.0f;
    private ScaleGestureDetector scaleGestureDetector;

    private PointF lastTouchPoint;

    public ZoomableImageView(Context context) {
        super(context);
        initialize(context);
    }

    public ZoomableImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initialize(context);
    }

    public ZoomableImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initialize(context);
    }

    private void initialize(Context context) {
        matrix = new Matrix();
        scaleGestureDetector = new ScaleGestureDetector(context, this);
        setScaleType(ScaleType.MATRIX);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        scaleGestureDetector.onTouchEvent(event);

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                lastTouchPoint = new PointF(event.getX(), event.getY());
                break;
            case MotionEvent.ACTION_MOVE:
                float dx = event.getX() - lastTouchPoint.x;
                float dy = event.getY() - lastTouchPoint.y;
                lastTouchPoint.set(event.getX(), event.getY());
                matrix.postTranslate(dx, dy);
                setImageMatrix(matrix);
                break;
        }

        return true;
    }

    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        scaleFactor *= detector.getScaleFactor();
        scaleFactor = Math.max(0.1f, Math.min(scaleFactor, 5.0f));

        matrix.setScale(scaleFactor, scaleFactor, detector.getFocusX(), detector.getFocusY());
        setImageMatrix(matrix);

        return true;
    }

    @Override
    public boolean onScaleBegin(ScaleGestureDetector detector) {
        return true;
    }

    @Override
    public void onScaleEnd(ScaleGestureDetector detector) {
        // Nothing to do here
    }
}

这就是XML

<com.coderfaysal.madrasah.ZoomableImageView
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     />

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