四捨五入只有一個圖像角 - 不是所有四個

Question

我用這很常見的類圓角：

public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int pixels) { 
     Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap 
       .getHeight(), Config.ARGB_8888); 
     Canvas canvas = new Canvas(output); 

     final int color = 0xff424242; 
     final Paint paint = new Paint(); 
     final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); 
     final RectF rectF = new RectF(rect); 
     final float roundPx = pixels; 

     paint.setAntiAlias(true); 
     canvas.drawARGB(0, 0, 0, 0); 
     paint.setColor(color); 
     canvas.drawRoundRect(rectF, roundPx, roundPx, paint); 

     paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); 
     canvas.drawBitmap(bitmap, rect, rect, paint); 

     return output; 
    } 

我想修改它，只有左上角是圓形的。我無法在代碼中找到這個參數嗎？有人可以協助嗎？

Answer 1

這可能不是最有效的方法，但可以通過在當前蒙版頂部繪製來填充圓角。您可以從當前代碼開始，然後在適當的區域（角點）上使用canvas.drawRect（在撥打canvas.drawRoundRect之後）。我想象這樣的事情會圓只有左上角：

public static Bitmap getRoundedTopLeftCornerBitmap(Bitmap bitmap, int pixels) { 
    Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap 
      .getHeight(), Config.ARGB_8888); 
    Canvas canvas = new Canvas(output); 

    final int color = 0xff424242; 
    final Paint paint = new Paint(); 
    final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); 
    final RectF rectF = new RectF(rect); 
    final float roundPx = pixels; 
    final Rect topRightRect = new Rect(bitmap.getWidth()/2, 0, bitmap.getWidth(), bitmap.getHeight()/2); 
    final Rect bottomRect = new Rect(0, bitmap.getHeight()/2, bitmap.getWidth(), bitmap.getHeight()); 

    paint.setAntiAlias(true); 
    canvas.drawARGB(0, 0, 0, 0); 
    paint.setColor(color); 
    canvas.drawRoundRect(rectF, roundPx, roundPx, paint); 
    // Fill in upper right corner 
    canvas.drawRect(topRightRect, paint); 
    // Fill in bottom corners 
    canvas.drawRect(bottomRect, paint); 

    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); 
    canvas.drawBitmap(bitmap, rect, rect, paint); 

    return output; 
} 

有一點優化，如果你喜歡，你可以在這裏做的，但我認爲它應該工作。總的想法絕對應該。我還沒有嘗試或測試過這段代碼，如果pixels > bitmap.getWidth()/2或pixels > bitmap.getHeight()/2看起來不正確。再一次，這也可能是真的。

Answer 2

這更多的是一個概念性的答案，但是您可以繪製一個圓角矩形，然後在您希望圓角的角落頂部劃兩個正常的矩形？

Answer 3

public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int topLeftX, int topLeftY, int topRightX, int topRightY, int bottomRightX, int bottomRightY, int bottomLeftX, int bottomLeftY) { 
     final Paint paint = new Paint(); 
     final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); 
     Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888); 
     Canvas canvas = new Canvas(output); 
     // the float array passed to this function defines the x/y values of the corners 
     // it starts top-left and works clockwise 
     // so top-left-x, top-left-y, top-right-x etc 
     RoundRectShape rrs = new RoundRectShape(new float[]{topLeftX, topLeftY, topRightX, topRightY, bottomRightX, bottomRightY, bottomLeftX, bottomLeftY}, null, null); 
     canvas.drawARGB(0, 0, 0, 0); 
     paint.setAntiAlias(true); 
     paint.setColor(0xFF000000); 
     rrs.resize(bitmap.getWidth(), bitmap.getHeight()); 
     rrs.draw(canvas, paint); 
     paint.setXfermode(new PorterDuffXfermode(android.graphics.PorterDuff.Mode.SRC_IN)); 
     canvas.drawBitmap(bitmap, rect, rect, paint); 
     return output; 
    } 

或者，你可以看到RoundRects.java源代碼 - 例如顯示如何製作圓角，提供SDK樣本：http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android-apps/4.3_r2.1/com/example/android/apis/graphics/RoundRects.java/

Answer 4

這是選擇的角落：

public static Bitmap getRoundedCornerBitmap(Context context, Bitmap bitmap, float roundDip, boolean roundTL, boolean roundTR, boolean roundBL, boolean roundBR) 
{ 
    try 
    { 

     Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888); 
     Canvas canvas = new Canvas(output); 

     final int color = 0xff424242; 
     final Paint paint = new Paint(); 
     final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); 
     final RectF rectF = new RectF(rect); 
     final float roundPx = convertDipToPixel(roundDip, context); 

     paint.setAntiAlias(true); 
     canvas.drawARGB(0, 0, 0, 0); 
     paint.setColor(color); 
     canvas.drawRoundRect(rectF, roundPx, roundPx, paint);// draw round 
                   // 4Corner 

     if (!roundTL) 
     { 
      Rect rectTL = new Rect(0, 0, bitmap.getWidth()/2, bitmap.getHeight()/2); 
      canvas.drawRect(rectTL, paint); 
     } 
     if (!roundTR) 
     { 
      Rect rectTR = new Rect(bitmap.getWidth()/2, 0, bitmap.getWidth(), bitmap.getHeight()/2); 
      canvas.drawRect(rectTR, paint); 
     } 
     if (!roundBR) 
     { 
      Rect rectBR = new Rect(bitmap.getWidth()/2, bitmap.getHeight()/2, bitmap.getWidth(), bitmap.getHeight()); 
      canvas.drawRect(rectBR, paint); 
     } 
     if (!roundBL) 
     { 
      Rect rectBL = new Rect(0, bitmap.getHeight()/2, bitmap.getWidth()/2, bitmap.getHeight()); 
      canvas.drawRect(rectBL, paint); 
     } 

     paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); 
     canvas.drawBitmap(bitmap, rect, rect, paint); 

     return output; 
    } catch (Exception e) 
    { 
    } 
    return bitmap; 
} 

Answer 5

如果您需要繪製（在畫布上）具有不同半徑的圓角，可以使用以下代碼：

private void drawAsymmetricRoundRect(Canvas canvas, RectF rectF, float[] radii, Paint paint) { 
    float topLeftX = rectF.left + radii[0]; 
    float topLeftY = rectF.top + radii[0]; 
    float topRightX = rectF.right - radii[1]; 
    float topRightY = rectF.top + radii[1]; 
    float bottomRightX = rectF.right - radii[2]; 
    float bottomRightY = rectF.bottom - radii[2]; 
    float bottomLeftY = rectF.bottom - radii[3]; 
    float bottomLeftX = rectF.left + radii[3]; 
    RectF topLeftCorner = new RectF(rectF.left, rectF.top, topLeftX + radii[0], topLeftY + radii[0]); 
    RectF topRightCorner = new RectF(topRightX - radii[1], rectF.top, rectF.right, topRightY + radii[1]); 
    RectF bottomRightCorner = new RectF(bottomRightX - radii[2], bottomRightY - radii[2], rectF.right, rectF.bottom); 
    RectF bottomLeftCorner = new RectF(rectF.left, bottomLeftY - radii[3], bottomLeftX + radii[3], rectF.bottom); 

    canvas.drawArc(topLeftCorner, 180, 90, true, paint); 
    canvas.drawArc(topRightCorner, 270, 90, true, paint); 
    canvas.drawArc(bottomRightCorner, 0, 90, true, paint); 
    canvas.drawArc(bottomLeftCorner, 90, 90, true, paint); 
    canvas.drawRect(topLeftX, rectF.top, topRightX, bottomLeftY < bottomRightY ? bottomLeftY : bottomRightY, paint); //top rect 
    canvas.drawRect(topLeftX > bottomLeftX ? topLeftX : bottomLeftX, topRightY, rectF.right, bottomRightY, paint); //right rect 
    canvas.drawRect(bottomLeftX, topLeftY > topRightY ? topLeftY : topRightY, bottomRightX, rectF.bottom, paint); //bottom rect 
    canvas.drawRect(rectF.left, topLeftY, bottomRightX < topRightX ? bottomRightX : topRightX, bottomLeftY, paint); //left rect 
} 

float[] radii是浮點陣列（長度= 4），其存儲你的角部的半徑的尺寸（順時針，從左上角=>{topLeft, topRight, bottomRight, bottomLeft}開始）。

基本上這種方法繪製4弧（角），並填充4角之間的所有角落。

重要說明：我在此方法中放置了角RectFs的初始化以降低發佈代碼的複雜性。由於事實上你很可能會從你的onDraw()方法中調用這個方法，所以你應該提取這部分代碼，並將它放在你初始化其他地方的地方（只要你還沒有在onDraw()中初始化它們：P） 。