2D图形截取

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今天做的是2D的图片处理截取 ，虽然不是太难但是注意的点多了，以后没准能用得到，记下来吧。

1、 XML

<span style="font-size:18px;color:#ff6600;"><?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/frameLayout_1"    android:layout_width="match_parent"    android:layout_height="match_parent" >    <ImageView        android:layout_marginTop="0dp"        android:id="@+id/imageview"        android:layout_width="match_parent"        android:layout_height="match_parent"        />    <TextView        android:id="@+id/textviewshow"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="显示坐标"        android:textSize="20dp"        android:textColor="@color/colorAccent"        android:layout_gravity="left|bottom" /></FrameLayout></span><span style="color:#ff0000;"></span>

2、Java （一个）

<span style="font-size:14px;"><span style="color:#ff0000;"></span><span style="color:#ff9900;">import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Path;import android.graphics.Rect;import android.graphics.drawable.BitmapDrawable;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.MotionEvent;import android.view.View;import android.widget.FrameLayout;import android.widget.ImageView;import android.widget.TextView;</span><span style="color:#ff0000;"></span><span style="color:#ff9900;">import org.w3c.dom.Text;</span><span style="color:#ff0000;"></span><span style="color:#993300;">public class MainActivity extends AppCompatActivity {    private FrameLayout frameLayout;    private ImageView imageView;    private TextView textViewshow;    </span><span style="color:#ffcc00;">@Override</span><span style="color:#993300;">    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        frameLayout = (FrameLayout)findViewById(R.id.frameLayout_1);        imageView = (ImageView)findViewById(R.id.imageview);        textViewshow = (TextView)findViewById(R.id.textviewshow);        frameLayout.addView(new MyView(this));        </span><span style="color:#009900;">/**坐标显示方便调整图像大小         * */</span><span style="color:#993300;">        frameLayout.setOnTouchListener(new View.OnTouchListener() {            @Override            public boolean onTouch(View v, MotionEvent event) {                float x = event.getRawX();                float y = event.getRawY();                textViewshow.setText("当前坐标  X_" + x + "  " + "Y_" + y);                return false;            }        });    }    public class MyView extends View    {        public MyView(Context context)        {            super(context);        }        </span><span style="color:#ffcc00;">@Override</span><span style="color:#993300;">        protected void onDraw(Canvas canvas) {            Paint paint = new Paint();            String path = </span><span style="color:#ff0000;">"/data/NewFile/a3.jpg"</span><span style="color:#993300;">;</span><span style="color:#000066;">//自己需要往文件夹中放一张图片，路径还要加上png or jpg.</span><span style="color:#993300;">            Bitmap bitmap = BitmapFactory.decodeFile(path);</span><span style="color:#009900;">//获取通过解码得到的位图</span><span style="color:#993300;">            </span><span style="color:#009900;">/**             * public static Bitmap decodeFile (String pathName)             Decode a file path into a bitmap. If the specified file name is null, or cannot be decoded into a bitmap, the function returns null.             Parameters             pathNamecomplete path name for the file to be decoded.             Returns             the resulting decoded bitmap, or null if it could not be decoded.             * */</span><span style="color:#993300;">            canvas.drawBitmap(bitmap,0,30,paint);</span><span style="color:#33cc00;">//将获取的Bitmap对象绘制在画布上指定位置</span><span style="color:#993300;">            Rect src = new Rect(95,50,75,300);</span><span style="color:#009900;">//设置挖取的区域  可以为空，那么将整个照片进行截取show</span><span style="color:#993300;">            Rect dst = new Rect(420,30,500,120);</span><span style="color:#009900;">//设置绘制的区域</span><span style="color:#993300;">            canvas.drawBitmap(bitmap, src, dst, paint);</span><span style="color:#009900;">//绘制挖取到的图像</span><span style="color:#993300;">            </span><span style="color:#009900;">////使用颜色数组创建一个Bitmap对象</span><span style="color:#993300;">            Bitmap bitmap_1 = Bitmap.createBitmap(new int[]{Color.RED,Color.GREEN,Color.BLUE,Color.MAGENTA},4,1, Bitmap.Config.RGB_565);            imageView.setImageBitmap(bitmap_1);            super.onDraw(canvas);        }    }   </span><span style="color:#ffcc00;"> @Override</span><span style="color:#993300;">    protected void onDestroy() {        BitmapDrawable b = (BitmapDrawable)imageView.getDrawable();        if(b!= null && !b.getBitmap().isRecycled())        {            b.getBitmap().recycle();        }        super.onDestroy();    }}</span></span>

效果：

源代码：http://download.csdn.net/detail/csdnhejingzhou/9348707