这是我创建圆形图像的解决方案：
package com.campusapp;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Shader;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
public class CircularImageView extends ImageView {
private int borderWidth;
private int canvasSize;
private Bitmap image;
private Paint paint;
private Paint paintBorder;
public CircularImageView(final Context context) {
this(context, null);
}
public CircularImageView(Context context, AttributeSet attrs) {
this(context, attrs, R.attr.circularImageViewStyle);
}
public CircularImageView(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
// init paint
paint = new Paint();
paint.setAntiAlias(true);
paintBorder = new Paint();
paintBorder.setAntiAlias(true);
// load the styled attributes and set their properties
TypedArray attributes = context.obtainStyledAttributes(attrs, R.styleable.CircularImageView, defStyle, 0);
if(attributes.getBoolean(R.styleable.CircularImageView_border, true))
{
int defaultBorderSize = (int) (4 * getContext().getResources().getDisplayMetrics().density + 0.5f);
setBorderWidth(attributes.getDimensionPixelOffset(R.styleable.CircularImageView_border_width, defaultBorderSize));
setBorderColor(attributes.getColor(R.styleable.CircularImageView_border_color, Color.WHITE));
}
if(attributes.getBoolean(R.styleable.CircularImageView_shadow, false))
addShadow();
}
public void setBorderWidth(int borderWidth)
{
this.borderWidth = borderWidth;
this.requestLayout();
this.invalidate();
}
public void setBorderColor(int borderColor)
{
if (paintBorder != null)
paintBorder.setColor(borderColor);
this.invalidate();
}
public void addShadow()
{
setLayerType(LAYER_TYPE_SOFTWARE, paintBorder);
paintBorder.setShadowLayer(4.0f, 0.0f, 2.0f, Color.BLACK);
}
@Override
public void onDraw(Canvas canvas)
{
// load the bitmap
image = drawableToBitmap(getDrawable());
// init shader
if (image != null)
{
canvasSize = canvas.getWidth();
if(canvas.getHeight()<canvasSize)
canvasSize = canvas.getHeight();
BitmapShader shader = new BitmapShader(Bitmap.createScaledBitmap(image, canvasSize, canvasSize, false), Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
paint.setShader(shader);
// circleCenter is the x or y of the view's center
// radius is the radius in pixels of the cirle to be drawn
// paint contains the shader that will texture the shape
int circleCenter = (canvasSize - (borderWidth * 2)) / 2;
canvas.drawCircle(circleCenter + borderWidth, circleCenter + borderWidth, ((canvasSize - (borderWidth * 2)) / 2) + borderWidth - 4.0f, paintBorder);
canvas.drawCircle(circleCenter + borderWidth, circleCenter + borderWidth, ((canvasSize - (borderWidth * 2)) / 2) - 4.0f, paint);
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
int width = measureWidth(widthMeasureSpec);
int height = measureHeight(heightMeasureSpec);
setMeasuredDimension(width, height);
}
private int measureWidth(int measureSpec)
{
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.EXACTLY)
{
// The parent has determined an exact size for the child.
result = specSize;
}
else if (specMode == MeasureSpec.AT_MOST)
{
// The child can be as large as it wants up to the specified size.
result = specSize;
}
else
{
// The parent has not imposed any constraint on the child.
result = canvasSize;
}
return result;
}
private int measureHeight(int measureSpecHeight)
{
int result = 0;
int specMode = MeasureSpec.getMode(measureSpecHeight);
int specSize = MeasureSpec.getSize(measureSpecHeight);
if (specMode == MeasureSpec.EXACTLY)
{
// We were told how big to be
result = specSize;
}
else if (specMode == MeasureSpec.AT_MOST)
{
// The child can be as large as it wants up to the specified size.
result = specSize;
}
else
{
// Measure the text (beware: ascent is a negative number)
result = canvasSize;
}
return (result + 2);
}
public Bitmap drawableToBitmap(Drawable drawable)
{
if (drawable == null)
{
return null;
}
else if (drawable instanceof BitmapDrawable)
{
return ((BitmapDrawable) drawable).getBitmap();
}
Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),
drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
drawable.draw(canvas);
return bitmap;
}
}
创建类后，将您的ImageView 替换为以下代码：
<com.yourpkg.CircularImageView
android:layout_width="150dp"
android:layout_height="150dp"
android:src="@drawable/your_image"
app:border_color="#EEEEEE"
app:border_width="4dp"
app:shadow="true" />