ZoomControls - 放大/缩小按钮控件

最新推荐文章于 2025-08-14 23:47:29 发布

最新推荐文章于 2025-08-14 23:47:29 发布 · 31 阅读

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#移动开发

本文详细介绍了如何使用Android中的ZoomControls组件实现图片的放大和缩小功能。通过设置监听器响应放大和缩小按钮点击事件，实现对图片尺寸的动态调整。文章提供了完整的代码示例，包括XML布局文件和Java代码。

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zoom.setOnZoomInClickListener(new OnClickListener() { @Override public void onClick(View v) { int bmpWidth = imgBmp.getWidth() ; int bmpHeight = imgBmp.getHeight(); double scale = 1.25 ; scaleWidth = (float) (scaleWidth* scale) ; scaleHeight = (float) (scaleHeight * scale) ; Matrix matrix = new Matrix() ; matrix.postScale(scaleWidth, scaleHeight); oldBitmap = Bitmap.createBitmap(imgBmp); resizeBitmap = Bitmap.createBitmap(oldBitmap, 0, 0, bmpWidth, bmpHeight, matrix, true); mSwitcher.setImageDrawable(new BitmapDrawable(resizeBitmap)); if (null != oldBitmap && !oldBitmap.isRecycled()) { imgBmp.recycle(); } oldBitmap = resizeBitmap ; imgBmp = oldBitmap ; } }) ; zoom.setOnZoomOutClickListener(new OnClickListener() { @Override public void onClick(View v) { int bmpWidth = imgBmp.getWidth() ; int bmpHeight = imgBmp.getHeight(); double scale = 0.5 ; scaleWidth = (float) (scaleWidth* scale) ; scaleHeight = (float) (scaleHeight * scale) ; Matrix matrix = new Matrix() ; matrix.postScale(scaleWidth, scaleHeight); oldBitmap = Bitmap.createBitmap(imgBmp); resizeBitmap = Bitmap.createBitmap(oldBitmap, 0, 0, bmpWidth, bmpHeight, matrix, true); mSwitcher.setImageDrawable(new BitmapDrawable(resizeBitmap)); if (null != oldBitmap && !oldBitmap.isRecycled()) { imgBmp.recycle(); } oldBitmap = resizeBitmap ; imgBmp = oldBitmap ; } }); package com.webabcd.view;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Toast;import android.widget.ZoomControls;public class _ZoomControls extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.zoomcontrols); setTitle("ZoomControls"); ZoomControls zoomControls = (ZoomControls) this.findViewById(R.id.zoomControls); // setOnZoomInClickListener() - 响应单击放大按钮的事件 zoomControls.setOnZoomInClickListener(new OnClickListener() { public void onClick(View v) { Toast.makeText(_ZoomControls.this, "单击了放大按钮", Toast.LENGTH_SHORT).show(); } }); // setOnZoomOutClickListener() - 响应单击缩小按钮的事件 zoomControls.setOnZoomOutClickListener(new OnClickListener() { public void onClick(View v) { Toast.makeText(_ZoomControls.this, "单击了缩小按钮", Toast.LENGTH_SHORT).show(); } }); }} <?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent">  <ZoomControls android:id="@+id/zoomControls" android:layout_width="wrap_content" android:layout_height="wrap_content"></ZoomControls></LinearLayout>