自定义View实现图片的绘制、旋转、缩放

 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     android:id="@+id/imageid"
 3     android:layout_width="fill_parent"
 4     android:layout_height="fill_parent"
 5     android:orientation="vertical">
 6 
 7     <Button android:id="@+id/buttonLeft"
 8         android:text="图片向左移动" 
 9         android:layout_width="fill_parent"
10         android:layout_height="wrap_content" />
11     <Button android:id="@+id/buttonRight"
12         android:text="图片向右移动"
13         android:layout_width="fill_parent"
14         android:layout_height="wrap_content"/>
15     <Button android:id="@+id/buttonRotationLeft"
16         android:text="图片向左旋转"
17         android:layout_width="fill_parent"
18         android:layout_height="wrap_content" />
19     <Button android:id="@+id/buttonRotationRight"
20         android:text="图片向右旋转"
21         android:layout_width="fill_parent"
22         android:layout_height="wrap_content" />
23     <Button android:id="@+id/buttonNarrow"
24         android:text="图片缩小"
25         android:layout_width="fill_parent"
26         android:layout_height="wrap_content" />
27     <Button android:id="@+id/buttonEnlarge"
28         android:text="图片放大"
29         android:layout_width="fill_parent"
30         android:layout_height="wrap_content" />
31 
32 </LinearLayout>

  1 import android.app.Activity;
  2 import android.os.Bundle;
  3 import android.view.View;
  4 import android.content.Context;
  5 import android.graphics.Paint;
  6 import android.graphics.Bitmap;
  7 import android.graphics.BitmapFactory;
  8 import android.graphics.Matrix;
  9 import android.graphics.Canvas;
 10 import android.widget.LinearLayout;
 11 import android.widget.Button;
 12 
 13 public class MainActivity extends Activity {
 14     ImageView imageView = null;
 15     
 16     @Override
 17     protected void onCreate(Bundle savedInstanceState) {
 18         super.onCreate(savedInstanceState);
 19         setContentView(R.layout.activity_main);
 20         
 21         //    动态加载图片到LinearLayout中
 22         imageView = new ImageView(this);
 23         LinearLayout ll = (LinearLayout) findViewById(R.id.imageid);
 24         ll.addView(imageView);
 25         //    向左移动
 26         Button btnLeft = (Button) findViewById(R.id.buttonLeft);
 27         btnLeft.setOnClickListener(new View.OnClickListener() {
 28             @Override
 29             public void onClick(View arg0) {
 30                 // TODO Auto-generated method stub
 31                 imageView.setPosLeft();
 32             }
 33         });
 34         //    向右移动
 35         Button btnRight = (Button) findViewById(R.id.buttonRight);
 36         btnRight.setOnClickListener(new View.OnClickListener() {
 37             @Override
 38             public void onClick(View arg0) {
 39                 // TODO Auto-generated method stub
 40                 imageView.setPosRight();
 41             }
 42         });
 43         
 44         //    向左旋转
 45         Button btnRotationLeft = (Button)findViewById(R.id.buttonRotationLeft);
 46         btnRotationLeft.setOnClickListener(new View.OnClickListener() {
 47             @Override
 48             public void onClick(View arg0) {
 49                 // TODO Auto-generated method stub
 50                 imageView.setRotationLeft();
 51             }
 52         });
 53         //    向右旋转
 54         Button btnRotationRight = (Button)findViewById(R.id.buttonRotationRight);
 55         btnRotationRight.setOnClickListener(new View.OnClickListener() {
 56             @Override
 57             public void onClick(View arg0) {
 58                 // TODO Auto-generated method stub
 59                 imageView.setRotationRight();
 60             }
 61         });
 62         
 63         //    放大图片
 64         Button btnEnlarge = (Button)findViewById(R.id.buttonEnlarge);
 65         btnEnlarge.setOnClickListener(new View.OnClickListener() {
 66             @Override
 67             public void onClick(View arg0) {
 68                 // TODO Auto-generated method stub
 69                 imageView.setEnlarge();
 70             }
 71         });
 72         //    缩小图片
 73         Button btnNarrow = (Button)findViewById(R.id.buttonNarrow);
 74         btnNarrow.setOnClickListener(new View.OnClickListener() {
 75             @Override
 76             public void onClick(View arg0) {
 77                 // TODO Auto-generated method stub
 78                 imageView.setNarrow();
 79             }
 80         });
 81     }
 82     
 83     //    自定义图片View
 84     class ImageView extends View {
 85         private Paint paint = null;    //    画笔
 86         private Bitmap bitmap = null;    //    图片位图
 87         private Bitmap bitmapDisplay = null;
 88         private Matrix matrix = null;
 89         private int nBitmapWidth = 0;    //    图片的宽度
 90         private int nBitmapHeight = 0;    //    图片的高度
 91         private int nPosX = 120;    //    图片所在的位置X
 92         private int nPosY = 10;    //    图片所在的位置Y
 93         private float fAngle = 0.0f;    //    图片旋转
 94         private float fScale = 1.0f;    //    图片缩放 1.0表示为原图
 95         
 96         public ImageView(Context context) {
 97             super(context);
 98             
 99             paint = new Paint();
100             paint.setFlags(Paint.ANTI_ALIAS_FLAG);
101             
102             //    加载需要操作的图片
103             bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.image);
104             bitmapDisplay = bitmap;
105             
106             matrix = new Matrix();
107             //    获取图片高度和宽度
108             nBitmapWidth = bitmap.getWidth();
109             nBitmapHeight = bitmap.getHeight();
110         }
111         
112         //    向左移动
113         public void setPosLeft() {
114             nPosX -= 10; 
115         }
116         //    向右移动
117         public void setPosRight() {
118             nPosX += 10;
119         }
120         
121         //    向左旋转
122         public void setRotationLeft() {
123             fAngle--;
124             setAngle();
125         }
126         //    向右旋转
127         public void setRotationRight() {
128             fAngle++;
129             setAngle();
130         }
131         
132         //    图片放大
133         public void setEnlarge() {
134             if (fScale < 2) {
135                 fScale += 0.1f;
136                 setScale();
137             }
138         }
139         //    图片缩小
140         public void setNarrow() {
141             if (fScale > 0.5) {
142                 fScale -= 0.1f;
143                 setScale();
144             }
145         }
146         
147         //    设置旋转比例
148         private void setAngle() {
149             matrix.reset();
150             matrix.setRotate(fAngle);
151             bitmapDisplay = Bitmap.createBitmap(bitmap,0,0,nBitmapWidth,nBitmapHeight,matrix,true);
152         }
153         
154         //    设置缩放比例
155         private void setScale() {
156             matrix.reset();
157             matrix.postScale(fScale, fScale);
158             bitmapDisplay = Bitmap.createBitmap(bitmap,0,0,nBitmapWidth,nBitmapHeight,matrix,true);
159         }
160         
161         @Override
162         protected void onDraw(Canvas canvas) {
163             super.onDraw(canvas);
164             canvas.drawBitmap(bitmapDisplay, nPosX, nPosY, paint);
165             invalidate();
166         }
167     }
168 }