Android教程網
設為首頁|加入收藏
  1. 首頁
  2. Android 技術
  3. Android 手機
  4. Android 系統教程
  5. Android 游戲
 Android教程網 >> Android技術 >> 關於Android編程 >> Android實現圓形的圖片邊角

Android實現圓形的圖片邊角

編輯：關於Android編程

ImageView沒有邊角圓化的設置，但是可以通過代碼設置實現。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 {
	@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;
		}
	}
}

 

  1. 上一頁:
  2. 下一頁:
關於Android編程
Android編程入門Android技術基礎Android資訊關於Android編程Android開發Android開發環境Android開發實例
相關文章
熱門文章
Android的Fragment中onActivityResult不被調用的解決方案(絕對管用) Android中實現TCP和UDP傳輸實例 android中Activity詳解（生命周期、以各種方式啟動Activity、狀態保存，完全退出等） Android開發——隱式意圖 Android倒計時功能的實現 qq厘米秀怎麼邀請？qq厘米秀使用常見問題及解決方法匯總
Android中ContentProvider組件數據共享

ContentProvider的功能和意義：主要用於對外共享數據，也就是
Android安全機制——操作系統安全機制-進程、用戶與文件安全

1.進程，線程2.多用戶，多用戶邊界（確定用戶可操作，訪問的資源，文件，
運動目標跟蹤（八）--時空上下文(STC)跟蹤原理

從原理可以看出，STC在相機運動環境中，效果不會太好，尤其是在高速運動環
android自定義LinearLayout和View

自定義線性布局經常用到：第一種是在擴展的LinearLayout構造函數
閱讀排行版
Copyright © Android教程網 All Rights Reserved