Android图片放大缩小ZoomControls控件 Android编程实现图片放大缩小功能ZoomControls控件用法实例
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本文实例讲述了Android编程实现图片放大缩小功能ZoomControls控件用法。分享给大家供大家参考,具体如下:
MainActivity代码:
package example.com.myapplication; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Matrix; import android.os.Bundle; import android.util.DisplayMetrics; import android.view.View; import android.view.View.OnClickListener; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.ZoomControls; public class MainActivity extends Activity { private LinearLayout llLayout; private ZoomControls zoomcontrols; private ImageView img; private int id=0; private int displayWidth; private int displayHeight; private float scaleWidth = 1; private float scaleHeight = 1; private Bitmap bitmap; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); llLayout =(LinearLayout)findViewById(R.id.layout); //取得屏幕分辨率大小 DisplayMetrics dm = new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(dm); displayWidth = dm.widthPixels; //屏幕高度减去zoomControls的高度 displayHeight = dm.heightPixels; bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.c); img =(ImageView)findViewById(R.id.image); //zoom.hide();隐藏zoomControls //zoom.show();显示zoomCOntrols zoomcontrols =(ZoomControls)findViewById(R.id.zoomcontrol); img =(ImageView)findViewById(R.id.image); zoomcontrols.setIsZoomInEnabled(true); zoomcontrols.setIsZoomOutEnabled(true); //图片放大 zoomcontrols.setOnZoomInClickListener(new OnClickListener() { public void onClick(View v) { int bmpWidth = bitmap.getWidth(); int bmpHeight = bitmap.getHeight(); //设置图片放大但比例 double scale = 1.25; //计算这次要放大的比例 scaleWidth =(float)(scaleWidth*scale); scaleHeight =(float)(scaleHeight*scale); //产生新的大小但Bitmap对象 Matrix matrix = new Matrix(); matrix.postScale(scaleWidth, scaleHeight); Bitmap resizeBmp = Bitmap.createBitmap(bitmap,0,0,bmpWidth,bmpHeight,matrix,true); img.setImageBitmap(resizeBmp); } }); //图片减小 zoomcontrols.setOnZoomOutClickListener(new OnClickListener() { public void onClick(View v) { int bmpWidth = bitmap.getWidth(); int bmpHeight = bitmap.getHeight(); //设置图片放大但比例 double scale = 0.8; //计算这次要放大的比例 scaleWidth =(float)(scaleWidth*scale); scaleHeight =(float)(scaleHeight*scale); //产生新的大小但Bitmap对象 Matrix matrix = new Matrix(); matrix.postScale(scaleWidth, scaleHeight); Bitmap resizeBmp = Bitmap.createBitmap(bitmap,0,0,bmpWidth,bmpHeight,matrix,true); img.setImageBitmap(resizeBmp); } }); } }
activity_main布局文件代码:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/layout" > <ImageView android:id="@+id/image" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/c" /> <ZoomControls android:id="@+id/zoomcontrol" android:layout_gravity="bottom" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout>
常见方法说明:
hasFocus():判断焦点
hide():隐藏
onTouchEvent(MotionEvent event):现这个方法来处理触摸屏移动事件
setIsZoomInEnabled(boolean isEnabled):是否允许放大
setIsZoomOutEnabled(boolean isEnabled):是否允许缩小
setOnZoomInClickListener(View.OnClickListener listener):注册放大监听器
setOnZoomOutClickListener(View.OnClickListener listener):注册缩小监听器
setZoomSpeed(long speed):设置缩放速度
show():显示
希望本文所述对大家Android程序设计有所帮助。
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