摘要:本文将带你了解Android应用开发之Android自定义ImageView实现图片圆形 ,椭圆和矩形圆角显示,希望本文对大家学Android有所帮助
本文将带你了解Android应用开发之Android自定义ImageView实现图片圆形 ,椭圆和矩形圆角显示,希望本文对大家学Android有所帮助
android中的ImageView只能显示矩形的图片,为了用户体验更多,Android实现圆角矩形,圆形或者椭圆等图形,一般通过自定义ImageView来实现,首先获取到图片的Bitmap,然后通过Paint和onDraw()进行圆形图片显示。
效果图:
代码:
Html代码 activity_image.xml
<LinearLayoutxmlns:android="//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
android:id="@+id/roundRect"
android:layout_width="286dp"
android:layout_height="190dp"
android:layout_marginTop="10dp"
android:src="@drawable/l1">
<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">
Java代码 自定义ImageView类 /** * 实现圆形、圆角,椭圆等自定义图片View。 * @author zq * */ public class ZQImageViewRoundOval extends ImageView { private Paint mPaint; private int mWidth; private int mHeight; private int mRadius;//圆半径 private RectF mRect;//矩形凹行大小 private int mRoundRadius;// 圆角大小 private BitmapShader mBitmapShader;//图形渲染 private Matrix mMatrix; private int mType;// 记录是圆形还是圆角矩形 public static final int TYPE_CIRCLE = 0;// 圆形 public static final int TYPE_ROUND = 1;// 圆角矩形 public static final int TYPE_OVAL = 2;//椭圆形 public static final int DEFAUT_ROUND_RADIUS = 10;//默认圆角大小 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); // 如果是绘制圆形,则强制宽高大小一致 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()); } /** * 设置BitmapShader */ private void setBitmapShader() { Drawable drawable = getDrawable(); if (null ==drawable) { return; } Bitmap bitmap = drawableToBitmap(drawable); // 将bitmap作为着色器来创建一个BitmapShader mBitmapShader = newBitmapShader(bitmap, TileMode.CLAMP, TileMode.CLAMP); float scale =1.0f; if (mType == TYPE_CIRCLE) { // 拿到bitmap宽或高的小值 int bSize =Math.min(bitmap.getWidth(), bitmap.getHeight()); scale = mWidth * 1.0f /bSize; } else if (mType == TYPE_ROUND || mType == TYPE_OVAL) { // 如果图片的宽或者高与view的宽高不匹配,计算出需要缩放的比例;缩放后的图片的宽高,一定要大于我们view的宽高;所以我们这里取大值; scale = Math.max(getWidth() * 1.0f/ bitmap.getWidth(), getHeight() * 1.0f / bitmap.getHeight()); } // shader的变换矩阵,我们这里主要用于放大或者缩小 mMatrix.setScale(scale,scale); // 设置变换矩阵 mBitmapShader.setLocalMatrix(mMatrix); mPaint.setShader(mBitmapShader); } /** * drawable转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; } /** * 单位dp转单位px */ public int dpTodx(int dp){ return (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp,getResources().getDisplayMetrics()); } public int getType(){ return mType; } /** * 设置图片类型:圆形、圆角矩形、椭圆形 * @param mType */ public void setType(int mType) { if(this.mType !=mType){ this.mType = mType; invalidate(); } } public int getRoundRadius() { return mRoundRadius; } /** * 设置圆角大小 * @parammRoundRadius */ public void setRoundRadius(int mRoundRadius) { if(this.mRoundRadius !=mRoundRadius){ this.mRoundRadius =mRoundRadius; invalidate(); } } } 自定义ImageView类
/**
* 实现圆形、圆角,椭圆等自定义图片View。
* @author zq
*
*/
public class ZQImageViewRoundOval extends ImageView {
private Paint mPaint;
private int mWidth;
private int mHeight;
private int mRadius;//圆半径
private RectF mRect;//矩形凹行大小
private int mRoundRadius;// 圆角大小
private BitmapShader mBitmapShader;//图形渲染
private Matrix mMatrix;
private int mType;// 记录是圆形还是圆角矩形
public static final int TYPE_CIRCLE = 0;// 圆形
public static final int TYPE_ROUND = 1;// 圆角矩形
public static final int TYPE_OVAL = 2;//椭圆形
public static final int DEFAUT_ROUND_RADIUS = 10;//默认圆角大小
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);
// 如果是绘制圆形,则强制宽高大小一致
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());
}
/**
* 设置BitmapShader
*/
private void setBitmapShader() {
Drawable drawable = getDrawable();
if (null ==drawable) {
return;
}
Bitmap bitmap = drawableToBitmap(drawable);
// 将bitmap作为着色器来创建一个BitmapShader
mBitmapShader = newBitmapShader(bitmap, TileMode.CLAMP, TileMode.CLAMP);
float scale =1.0f;
if (mType == TYPE_CIRCLE) {
// 拿到bitmap宽或高的小值
int bSize =Math.min(bitmap.getWidth(), bitmap.getHeight());
scale = mWidth * 1.0f /bSize;
} else if (mType == TYPE_ROUND || mType == TYPE_OVAL) {
// 如果图片的宽或者高与view的宽高不匹配,计算出需要缩放的比例;缩放后的图片的宽高,一定要大于我们view的宽高;所以我们这里取大值;
scale = Math.max(getWidth() * 1.0f/ bitmap.getWidth(), getHeight() * 1.0f / bitmap.getHeight());
}
// shader的变换矩阵,我们这里主要用于放大或者缩小
mMatrix.setScale(scale,scale);
// 设置变换矩阵
mBitmapShader.setLocalMatrix(mMatrix);
mPaint.setShader(mBitmapShader);
}
/**
* drawable转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;
}
/**
* 单位dp转单位px
*/
public int dpTodx(int dp){
return (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
dp,getResources().getDisplayMetrics());
}
public int getType(){
return mType;
}
/**
* 设置图片类型:圆形、圆角矩形、椭圆形
* @param mType
*/
public void setType(int mType) {
if(this.mType !=mType){
this.mType = mType;
invalidate();
}
}
public int getRoundRadius() {
return mRoundRadius;
}
/**
* 设置圆角大小
* @parammRoundRadius
*/
public void setRoundRadius(int mRoundRadius) {
if(this.mRoundRadius !=mRoundRadius){
this.mRoundRadius =mRoundRadius;
invalidate();
}
}
}
Java代码 MainActivity类 /**** * * 自定义ImageView实现圆形图片,圆角矩形图片 椭圆图片 * * @authorzq * */ public class MainActivity extends Activity { private ZQImageViewRoundOvaliv_circle;//圆形图片 private ZQImageViewRoundOvaliv_roundRect;//圆角矩形图片 private ZQImageViewRoundOvaliv_oval;//椭圆图片 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_image); initViews(); } /** * 初始化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);//矩形凹行大小 iv_oval.setType(ZQImageViewRoundOval.TYPE_OVAL); iv_oval.setRoundRadius(45);//圆角大小 } } MainActivity类
/****
*
* 自定义ImageView实现圆形图片,圆角矩形图片 椭圆图片
*
* @authorzq
*
*/
public class MainActivity extends Activity {
private ZQImageViewRoundOvaliv_circle;//圆形图片
private ZQImageViewRoundOvaliv_roundRect;//圆角矩形图片
private ZQImageViewRoundOvaliv_oval;//椭圆图片
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_image);
initViews();
}
/**
* 初始化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);//矩形凹行大小
iv_oval.setType(ZQImageViewRoundOval.TYPE_OVAL);
iv_oval.setRoundRadius(45);//圆角大小
}
}
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