ImageView in android can only display rectangular pictures. For more user experience, Android implements shapes such as rounded rectangles, circles or ellipses , which are generally implemented by customizing ImageView . First, get the Bitmap of the picture, and then use Paint and onDraw . ( ) for circular picture display.
Effect picture:
Code:
activity_image.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.example.imageviewdrawdemo.ZQImageViewRoundOval
android:id="@+id/cicle"
android:layout_width="100dp"
android:layout_height="100dp"
android:src="@drawable/qie">
</com.example.imageviewdrawdemo.ZQImageViewRoundOval>
<com.example.imageviewdrawdemo.ZQImageViewRoundOval
android:id="@+id/roundRect"
android:layout_width="286dp"
android:layout_height="190dp"
android:layout_marginTop="10dp"
android:src="@drawable/l1">
</com.example.imageviewdrawdemo.ZQImageViewRoundOval>
<com.example.imageviewdrawdemo.ZQImageViewRoundOval
android:id="@+id/oval"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:src="@drawable/l2">
</com.example.imageviewdrawdemo.ZQImageViewRoundOval>
</LinearLayout>
Custom ImageView class
/**
* Realize custom picture View such as circle, rounded corner, ellipse, etc.
* @author zq
*
*/
public class ZQImageViewRoundOval extends ImageView {
private Paint mPaint;
private int mWidth;
private int mHeight;
private int mRadius;//Circle radius
private RectF mRect;//Rectangular concave row size
private int mRoundRadius;// rounded corner size
private BitmapShader mBitmapShader;//Graphics rendering
private Matrix mMatrix;
private int mType;// whether the record is a circle or a rounded rectangle
public static final int TYPE_CIRCLE = 0;// 圆形
public static final int TYPE_ROUND = 1;// rounded rectangle
public static final int TYPE_OVAL = 2;//Oval
public static final int DEFAUT_ROUND_RADIUS = 10;//Default rounded corner size
public ZQImageViewRoundOval(Context context) {
this(context, null);
// TODOAuto-generated constructor stub
}
public ZQImageViewRoundOval(Context context, AttributeSet attrs) {
this(context,attrs, 0);
// TODOAuto-generated constructor stub
}
public ZQImageViewRoundOval(Context context, AttributeSet attrs, int defStyle){
super(context,attrs, defStyle);
initView();
}
private void initView() {
mPaint = new Paint();
mPaint.setAntiAlias(true);
mMatrix = new Matrix();
mRoundRadius = DEFAUT_ROUND_RADIUS;
}
@Override
protected void onMeasure(int widthMeasureSpec, intheightMeasureSpec) {
// TODOAuto-generated method stub
super.onMeasure(widthMeasureSpec,heightMeasureSpec);
// If you are drawing a circle, force the width and height to be the same size
if (mType == TYPE_CIRCLE) {
mWidth = Math.min(getMeasuredWidth(),getMeasuredHeight());
mRadius = mWidth / 2;
setMeasuredDimension(mWidth, mWidth);
}
}
@Override
protected void onDraw(Canvas canvas) {
if (null ==getDrawable()) {
return;
}
setBitmapShader();
if (mType == TYPE_CIRCLE) {
canvas.drawCircle(mRadius, mRadius, mRadius, mPaint);
} else if (mType == TYPE_ROUND) {
mPaint.setColor(Color.RED);
canvas.drawRoundRect(mRect, mRoundRadius, mRoundRadius, mPaint);
}else if(mType == TYPE_OVAL){
canvas.drawOval(mRect, mPaint);
}
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
// TODOAuto-generated method stub
super.onSizeChanged(w,h, oldw, oldh);
mRect = new RectF(0,0, getWidth(), getHeight());
}
/**
* Set BitmapShader
*/
private void setBitmapShader() {
Drawable drawable = getDrawable();
if (null ==drawable) {
return;
}
Bitmap bitmap = drawableToBitmap(drawable);
// Create a BitmapShader with the bitmap as a shader
mBitmapShader = newBitmapShader(bitmap, TileMode.CLAMP, TileMode.CLAMP);
float scale =1.0f;
if (mType == TYPE_CIRCLE) {
// Get the small value of bitmap width or height
int bSize =Math.min(bitmap.getWidth(), bitmap.getHeight());
scale = mWidth * 1.0f /bSize;
} else if (mType == TYPE_ROUND || mType == TYPE_OVAL) {
// If the width or height of the picture does not match the width and height of the view, calculate the ratio that needs to be scaled; the width and height of the scaled picture must be greater than the width and height of our view; so we take the larger value here;
scale = Math.max(getWidth() * 1.0f/ bitmap.getWidth(), getHeight() * 1.0f / bitmap.getHeight());
}
// The transformation matrix of the shader, we are mainly used here to enlarge or reduce
mMatrix.setScale(scale,scale);
// set transformation matrix
mBitmapShader.setLocalMatrix(mMatrix);
mPaint.setShader (mBitmapShader);
}
/**
* drawable to bitmap
*
* @paramdrawable
* @return
*/
private Bitmap drawableToBitmap(Drawable drawable) {
if (drawableinstanceof BitmapDrawable) {
BitmapDrawable bitmapDrawable =(BitmapDrawable) drawable;
returnbitmapDrawable.getBitmap();
}
int w =drawable.getIntrinsicWidth();
int h =drawable.getIntrinsicHeight();
Bitmap bitmap = Bitmap.createBitmap(w,h, Config.ARGB_8888);
Canvas canvas = newCanvas(bitmap);
drawable.setBounds(0, 0, w, h);
drawable.draw(canvas);
return bitmap;
}
/**
* Unit dp to unit px
*/
public int dpTodx(int dp){
return (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
dp,getResources().getDisplayMetrics());
}
public int getType(){
return mType;
}
/**
* Set picture type: circle, rounded rectangle, oval
* @param mType
*/
public void setType(int mType) {
if(this.mType !=mType){
this.mType = mType;
invalidate();
}
}
public int getRoundRadius() {
return mRoundRadius;
}
/**
* Set the rounded corner size
* @parammRoundRadius
*/
public void setRoundRadius(int mRoundRadius) {
if(this.mRoundRadius !=mRoundRadius){
this.mRoundRadius =mRoundRadius;
invalidate();
}
}
}
MainActivity class
/****
*
* Customize ImageView to realize circular picture, rounded rectangular picture and ellipse picture
*
* @authorzq
*
*/
public class MainActivity extends Activity {
private ZQImageViewRoundOvaliv_circle;//Circle picture
private ZQImageViewRoundOvaliv_roundRect;//Round rectangle picture
private ZQImageViewRoundOvaliv_oval;//Ellipse picture
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate (savedInstanceState);
setContentView(R.layout.activity_image);
initViews();
}
/**
* Initialize Views
*/
private void initViews(){
iv_circle =(ZQImageViewRoundOval)findViewById(R.id.cicle);
iv_roundRect =(ZQImageViewRoundOval)findViewById(R.id.roundRect);
iv_oval =(ZQImageViewRoundOval)findViewById(R.id.oval);
iv_roundRect.setType(ZQImageViewRoundOval.TYPE_ROUND);
iv_roundRect.setRoundRadius(6);//Rectangular concave row size
iv_oval.setType(ZQImageViewRoundOval.TYPE_OVAL);
iv_oval.setRoundRadius(45);//Round size
}
}
Source code download:
Eclipse download: http://download.csdn.net/detail/dickyqie/9621330
AndroidStudio download: https://github.com/DickyQie/android-imageview