Android實現圓形的圖片邊角

ImageView沒有邊角圓化的設定，但是可以通過代碼設定實現。一個國外的碼農寫的方法。
 

 package com.example.roundrectshader;    import android.os.Bundle;  import android.view.LayoutInflater;  import android.view.View;  import android.view.ViewGroup;  import android.view.ViewGroup.LayoutParams;  import android.widget.ArrayAdapter;  import android.widget.ListView;  import android.widget.TextView;  import android.app.Activity;  import android.content.Context;  import android.graphics.Bitmap;  import android.graphics.BitmapFactory;  import android.graphics.BitmapShader;  import android.graphics.Canvas;  import android.graphics.ColorFilter;  import android.graphics.ComposeShader;  import android.graphics.Matrix;  import android.graphics.Paint;  import android.graphics.PixelFormat;  import android.graphics.PorterDuff;  import android.graphics.RadialGradient;  import android.graphics.Rect;  import android.graphics.RectF;  import android.graphics.Shader;  import android.graphics.drawable.Drawable;    public class StreamActivity extends Activity {      @Override      protected void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);            setContentView(R.layout.activity_stream);            StreamAdapter adapter = new StreamAdapter(this);          ((ListView) findViewById(R.id.main_list)).setAdapter(adapter);            adapter.add(new StreamItem(this, R.drawable.photo1, "Tufa at night", "Mono Lake, CA"));          adapter.add(new StreamItem(this, R.drawable.photo2, "Starry night", "Lake Powell, AZ"));          adapter.add(new StreamItem(this, R.drawable.photo3, "Racetrack playa", "Death Valley, CA"));          adapter.add(new StreamItem(this, R.drawable.photo4, "Napali coast", "Kauai, HI"));          adapter.add(new StreamItem(this, R.drawable.photo5, "Delicate Arch", "Arches, UT"));          adapter.add(new StreamItem(this, R.drawable.photo6, "Sierra sunset", "Lone Pine, CA"));          adapter.add(new StreamItem(this, R.drawable.photo7, "Majestic", "Grand Teton, WY"));      }        class StreamItem {          final Bitmap mBitmap;          final String mLine1;          final String mLine2;            StreamItem(Context c, int resid, String line1, String line2) {              mBitmap = BitmapFactory.decodeResource(c.getResources(), resid);              mLine1 = line1;              mLine2 = line2;          }      }        class StreamDrawable extends Drawable {          private static final boolean USE_VIGNETTE = true;            private final float mCornerRadius;          private final RectF mRect = new RectF();          private final BitmapShader mBitmapShader;          private final Paint mPaint;          private final int mMargin;            StreamDrawable(Bitmap bitmap, float cornerRadius, int margin) {              mCornerRadius = cornerRadius;                mBitmapShader = new BitmapShader(bitmap,                      Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);                mPaint = new Paint();              mPaint.setAntiAlias(true);              mPaint.setShader(mBitmapShader);                mMargin = margin;          }            @Override          protected void onBoundsChange(Rect bounds) {              super.onBoundsChange(bounds);              mRect.set(mMargin, mMargin, bounds.width() - mMargin, bounds.height() - mMargin);                if (USE_VIGNETTE) {                  RadialGradient vignette = new RadialGradient(                          mRect.centerX(), mRect.centerY() * 1.0f / 0.7f, mRect.centerX() * 1.3f,                          new int[] { 0, 0, 0x7f000000 }, new float[] { 0.0f, 0.7f, 1.0f },                          Shader.TileMode.CLAMP);                        Matrix oval = new Matrix();                  oval.setScale(1.0f, 0.7f);                  vignette.setLocalMatrix(oval);                        mPaint.setShader(                          new ComposeShader(mBitmapShader, vignette, PorterDuff.Mode.SRC_OVER));              }          }            @Override          public void draw(Canvas canvas) {              canvas.drawRoundRect(mRect, mCornerRadius, mCornerRadius, mPaint);          }            @Override          public int getOpacity() {              return PixelFormat.TRANSLUCENT;          }            @Override          public void setAlpha(int alpha) {              mPaint.setAlpha(alpha);          }            @Override          public void setColorFilter(ColorFilter cf) {              mPaint.setColorFilter(cf);          }             }          class StreamAdapter extends ArrayAdapter<StreamItem> {          private static final int CORNER_RADIUS = 24; // dips          private static final int MARGIN = 12; // dips            private final int mCornerRadius;          private final int mMargin;          private final LayoutInflater mInflater;            public StreamAdapter(Context context) {              super(context, 0);                            final float density = context.getResources().getDisplayMetrics().density;              mCornerRadius = (int) (CORNER_RADIUS * density + 0.5f);              mMargin = (int) (MARGIN * density + 0.5f);                mInflater = LayoutInflater.from(getContext());          }            @Override          public View getView(int position, View convertView, ViewGroup parent) {              ViewGroup view = null;                            if (convertView == null) {                  view = (ViewGroup) mInflater.inflate(R.layout.stream_item, parent, false);              } else {                  view = (ViewGroup) convertView;              }                StreamItem item = getItem(position);                StreamDrawable d = new StreamDrawable(item.mBitmap, mCornerRadius, mMargin);              view.setBackgroundDrawable(d);                ((TextView) view.findViewById(R.id.textView1)).setText(item.mLine1);              ((TextView) view.findViewById(R.id.textView2)).setText(item.mLine2);                int w = item.mBitmap.getWidth();              int h = item.mBitmap.getHeight();                float ratio = w / (float) h;                LayoutParams lp = view.getLayoutParams();              lp.width = getContext().getResources().getDisplayMetrics().widthPixels;              lp.height = (int) (lp.width / ratio);                return view;          }      }  }  package com.example.roundrectshader;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.view.ViewGroup.LayoutParams;import android.widget.ArrayAdapter;import android.widget.ListView;import android.widget.TextView;import android.app.Activity;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.BitmapShader;import android.graphics.Canvas;import android.graphics.ColorFilter;import android.graphics.ComposeShader;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.PixelFormat;import android.graphics.PorterDuff;import android.graphics.RadialGradient;import android.graphics.Rect;import android.graphics.RectF;import android.graphics.Shader;import android.graphics.drawable.Drawable;public class StreamActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_stream);StreamAdapter adapter = new StreamAdapter(this);((ListView) findViewById(R.id.main_list)).setAdapter(adapter);adapter.add(new StreamItem(this, R.drawable.photo1, "Tufa at night", "Mono Lake, CA"));adapter.add(new StreamItem(this, R.drawable.photo2, "Starry night", "Lake Powell, AZ"));adapter.add(new StreamItem(this, R.drawable.photo3, "Racetrack playa", "Death Valley, CA"));adapter.add(new StreamItem(this, R.drawable.photo4, "Napali coast", "Kauai, HI"));adapter.add(new StreamItem(this, R.drawable.photo5, "Delicate Arch", "Arches, UT"));adapter.add(new StreamItem(this, R.drawable.photo6, "Sierra sunset", "Lone Pine, CA"));adapter.add(new StreamItem(this, R.drawable.photo7, "Majestic", "Grand Teton, WY"));}class StreamItem {final Bitmap mBitmap;final String mLine1;final String mLine2;StreamItem(Context c, int resid, String line1, String line2) {mBitmap = BitmapFactory.decodeResource(c.getResources(), resid);mLine1 = line1;mLine2 = line2;}}class StreamDrawable extends Drawable {private static final boolean USE_VIGNETTE = true;private final float mCornerRadius;private final RectF mRect = new RectF();private final BitmapShader mBitmapShader;private final Paint mPaint;private final int mMargin;StreamDrawable(Bitmap bitmap, float cornerRadius, int margin) {mCornerRadius = cornerRadius;mBitmapShader = new BitmapShader(bitmap,Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);mPaint = new Paint();mPaint.setAntiAlias(true);mPaint.setShader(mBitmapShader);mMargin = margin;}@Overrideprotected void onBoundsChange(Rect bounds) {super.onBoundsChange(bounds);mRect.set(mMargin, mMargin, bounds.width() - mMargin, bounds.height() - mMargin);if (USE_VIGNETTE) {RadialGradient vignette = new RadialGradient(mRect.centerX(), mRect.centerY() * 1.0f / 0.7f, mRect.centerX() * 1.3f,new int[] { 0, 0, 0x7f000000 }, new float[] { 0.0f, 0.7f, 1.0f },Shader.TileMode.CLAMP);Matrix oval = new Matrix();oval.setScale(1.0f, 0.7f);vignette.setLocalMatrix(oval);mPaint.setShader(new ComposeShader(mBitmapShader, vignette, PorterDuff.Mode.SRC_OVER));}}@Overridepublic void draw(Canvas canvas) {canvas.drawRoundRect(mRect, mCornerRadius, mCornerRadius, mPaint);}@Overridepublic int getOpacity() {return PixelFormat.TRANSLUCENT;}@Overridepublic void setAlpha(int alpha) {mPaint.setAlpha(alpha);}@Overridepublic void setColorFilter(ColorFilter cf) {mPaint.setColorFilter(cf);}}class StreamAdapter extends ArrayAdapter<StreamItem> {private static final int CORNER_RADIUS = 24; // dipsprivate static final int MARGIN = 12; // dipsprivate final int mCornerRadius;private final int mMargin;private final LayoutInflater mInflater;public StreamAdapter(Context context) {super(context, 0);final float density = context.getResources().getDisplayMetrics().density;mCornerRadius = (int) (CORNER_RADIUS * density + 0.5f);mMargin = (int) (MARGIN * density + 0.5f);mInflater = LayoutInflater.from(getContext());}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {ViewGroup view = null;if (convertView == null) {view = (ViewGroup) mInflater.inflate(R.layout.stream_item, parent, false);} else {view = (ViewGroup) convertView;}StreamItem item = getItem(position);StreamDrawable d = new StreamDrawable(item.mBitmap, mCornerRadius, mMargin);view.setBackgroundDrawable(d);((TextView) view.findViewById(R.id.textView1)).setText(item.mLine1);((TextView) view.findViewById(R.id.textView2)).setText(item.mLine2);int w = item.mBitmap.getWidth();int h = item.mBitmap.getHeight();float ratio = w / (float) h;LayoutParams lp = view.getLayoutParams();lp.width = getContext().getResources().getDisplayMetrics().widthPixels;lp.height = (int) (lp.width / ratio);return view;}}}