Android使用ImageView 制作透明圆弧实例代码

package com.chunk.customviewsdemo.views.ArcImageView;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.widget.ImageView;
import com.chunk.customviewsdemo.R;
/**
* Description:A custom ImageView with circular arc and text
* Author: XiaoYu
* Date: // :
*/
public class ArcImageView extends ImageView {
/**
* The default text size.
*/
private final float DEFAULT_TEXT_SIZE = ;
/**
* The default scale value which decides the width of arc.
*/
private final float DEFAULT_SCALE = .f;
/**
* The default transparency of arc.
*/
private final int DEFAULT_ARC_ALPHA =;
/**
* The default width of arc.
*/
private final int DEFAULT_ARC_WIDTH =;
/**
* The default angle that the arc starts with.
*/
private final int DEFAULT_START_ANGLE = ;
/**
* The default angle that the arc.
*/
private final int DEFAULT_SWEEP_ANGLE = ;
/**
* The default distance along the path to add to the text's starTing position.
*/
private final int DEFAULT_H_OFFSET = ;
/**
* The default distance above(-) or below(+) the path to position the text.
*/
private final int DEFAULT_V_OFFSET = ;
private Context mContext;
/**
* The text displayed on ImageView along arc.
*/
private String mDrawStr;
/**
* The font size of text.
*/
private float mTextSize = DEFAULT_TEXT_SIZE;
/**
* The scale value which decides the width of arc.
*/
private float mScale = DEFAULT_SCALE;
/**
* The transparency of arc.
*/
privatE int mArcAlpha = DEFAULT_ARC_ALPHA;
/**
* The width of arc.
*/
privatE int mArcWidth = DEFAULT_ARC_WIDTH;
/**
* The start angle of angle.
*/
privatE int mStartAngle = DEFAULT_START_ANGLE;
/**
* The swept angle of angle.
*/
privatE int mSweepAngle = DEFAULT_SWEEP_ANGLE;
/**
* The default distance along the path to add to the text's starTing position.
*/
private float mHOffset = DEFAULT_H_OFFSET;
/**
* The default distance above(-) or below(+) the path to position the text.
*/
private float mVOffset = DEFAULT_V_OFFSET;
/**
* The style of arc,all styles includes LEFT_TOP,LEFT_BOTTOM,RIGHT_TOP,RIGHT_BOTTOM,CENTER。
* of course,you can add your own style according to your demands.
*/
privatE int mDrawStyle;
/**
* The color of arc.
*/
privatE int mArcColor;
/**
* The color of text.
*/
privatE int mTextColor;
public ArcImageView(Context context) {
super(context);
this.mContext = context;
}
public ArcImageView(Context context,AttributeSet attrs) {
super(context,attrs);
this.mContext = context;
obtainAttributes(attrs);
}
public ArcImageView(Context context,AttributeSet attrs,int defStyleAttr) {
super(context,attrs,defStyleAttr);
this.mContext = context;
obtainAttributes(attrs);
}
/**
* Set the text that will be drawn on arc.
* @param drawStr the text content.
*/
public void setDrawStr(String drawStr) {
this.mDrawStr = drawStr;
//refresh this view
invalidate();
}
/**
* Set the transparency of arc.
* @param mArcAlpha the value of transparency.
*/
public void setArcAlpha(int mArcAlpha) {
this.mArcAlpha = mArcAlpha;
//refresh this view
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//draw arc
Paint arcPaint = new Paint();
arcPaint.setstrokeWidth(mArcWidth);
arcPaint.setStyle(Paint.Style.stroke);
arcPaint.setColor(mArcColor);
arcPaint.setAlpha(mArcAlpha);
int width = getWidth();
int height = getHeight();
float radius;
if (width > height) {
radius = mScale * height;
} else {
radius = mScale * width;
}
RectF oval = new RectF();
int center_x = width;
int center_y = height;
switch (mDrawStylE) {
case :
center_x = ;
center_y = ;
mStartAngle = ;
mSweepAngle = -;
break;
case :
center_x = ;
center_y = height;
mStartAngle = ;
mSweepAngle = ;
break;
case :
center_x = width;
center_y = ;
mStartAngle = ;
mSweepAngle = -;
break;
case :
center_x = width;
center_y = height;
mStartAngle = ;
mSweepAngle = ;
break;
case :
center_x = width / ;
center_y = height / ;
mStartAngle = ;
mSweepAngle = ;
break;
}
float left = center_x - radius;
float top = center_y - radius;
float right = center_x + radius;
float bottom = center_y + radius;
oval.set(left,top,right,bottom);
canvas.drawArc(oval,mStartAngle,mSweepAngle,false,arcPaint);
//draw text
Paint textPaint = new Paint();
textPaint.setTextSize(mTextSizE);
textPaint.setStyle(Paint.Style.FILL);
textPaint.setColor(mTextColor);
Path path = new Path();
path.addArc(oval,mSweepAnglE);
canvas.drawTextOnPath(mDrawStr,path,mHOffset,mVOffset,textPaint);
}
/**
* Obtain custom attributes that been defined in attrs.xml.
* @param attrs A collection of attributes.
*/
private void obtainAttributes(AttributeSet attrs) {
TypedArray ta = mContext.obtainStyledAttributes(attrs,R.styleable.ArcImageView);
mDrawStr = ta.getString(R.styleable.ArcImageView_drawStr);
mTextSize = ta.getDimension(R.styleable.ArcImageView_textSize,DEFAULT_TEXT_SIZE);
mArcAlpha = ta.getInteger(R.styleable.ArcImageView_arcAlpha,DEFAULT_ARC_ALPHA);
mArcWidth = ta.getInteger(R.styleable.ArcImageView_arcWidth,DEFAULT_ARC_WIDTH);
mStartAngle = ta.getInteger(R.styleable.ArcImageView_startAngle,DEFAULT_START_ANGLE);
mSweepAngle = ta.getInteger(R.styleable.ArcImageView_startAngle,DEFAULT_SWEEP_ANGLE);
mHOffset = ta.getInteger(R.styleable.ArcImageView_hOffset,DEFAULT_H_OFFSET);
mVOffset = ta.getInteger(R.styleable.ArcImageView_vOffset,DEFAULT_V_OFFSET);
mArcColor = ta.getColor(R.styleable.ArcImageView_arcColor,XCCCCCC);
mTextColor = ta.getColor(R.styleable.ArcImageView_textColor,XFFFFFF);
mDrawStyle = ta.geTint(R.styleable.ArcImageView_drawStyle,);
ta.recycle();
}
}

<?xml version="." encoding="utf-"?>
<resources>
<declare-styleable name="ArcImageView">
<attr name="drawStr" format="String" />
<attr name="textSize" format="dimension" />
<attr name="arcAlpha" format="Integer" />
<attr name="arcWidth" format="Integer" />
<attr name="startAngle" format="Integer" />
<attr name="sweepAngle" format="Integer" />
<attr name="scale" format="float" />
<attr name="hOffset" format="float" />
<attr name="vOffset" format="float" />
<attr name="drawStyle" format="enum">
<enum name="LEFT_TOP" value="" />
<enum name="LEFT_BOTTOM" value="" />
<enum name="RIGHT_TOP" value="" />
<enum name="RIGHT_BOTTOM" value="" />
<enum name="CENTER" value="" />
</attr>
<attr name="arcColor" format="color" />
<attr name="textColor" format="color" />
</declare-styleable>
</resources>

package com.chunk.customviewsdemo;
import android.os.bundle;
import android.support.v.app.AppCompatActivity;
import android.view.View;
import android.widget.button;
import com.chunk.customviewsdemo.views.ArcImageView.ArcImageView;
public class MainActivity extends AppCompatActivity implements View.onClickListener {
private ArcImageView aiv_one;
private ArcImageView aiv_two;
private ArcImageView aiv_three;
private ArcImageView aiv_four;
private Button btn_another_one;
privatE int mGroup = ;
@Override
protected void onCreate(Bundle savedInstanceStatE) {
super.onCreate(savedInstanceStatE);
setContentView(R.layout.activity_main);
aiv_one = (ArcImageView) findViewById(R.id.aiv_onE);
aiv_one.setArcAlpha();
aiv_two = (ArcImageView) findViewById(R.id.aiv_two);
aiv_two.setArcAlpha();
aiv_three = (ArcImageView) findViewById(R.id.aiv_threE);
aiv_three.setArcAlpha();
aiv_four = (ArcImageView) findViewById(R.id.aiv_four);
aiv_four.setArcAlpha();
btn_another_one = (Button) findViewById(R.id.btn_another_onE);
btn_another_one.setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_another_one:
if (mGroup == ) {
aiv_one.setDrawStr("苹果");
aiv_one.setBACkgroundresource(R.drawable.applE);
aiv_two.setDrawStr("柚子");
aiv_two.setBACkgroundresource(R.drawable.pineapplE);
aiv_three.setDrawStr("香蕉");
aiv_three.setBACkgroundresource(R.drawable.banana);
aiv_four.setDrawStr("菠萝");
aiv_four.setBACkgroundresource(R.drawable.pineapplE);
mGroup = ;
} else {
aiv_one.setDrawStr("牛排");
aiv_one.setBACkgroundresource(R.drawable.steak);
aiv_two.setDrawStr("海鲜");
aiv_two.setBACkgroundresource(R.drawable.seafood);
aiv_three.setDrawStr("奶酪");
aiv_three.setBACkgroundresource(R.drawable.cheesE);
aiv_four.setDrawStr("烧烤");
aiv_four.setBACkgroundresource(R.drawable.barbecuE);
mGroup = ;
}
break;
}
}
}

<LinearLayout
xmlns:android="http://scheR_306_11845@as.android.com/apk/res/android"
xmlns:custom="http://scheR_306_11845@as.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="dp"
android:layout_marginBottom="dp"
android:orientation="vertical" >
<Button
android:id="@+id/btn_another_one"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="换一组" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="dp"
android:layout_weight=""
android:orientation="horizontal" >
<RelativeLayout
android:layout_width="dp"
android:layout_weight=""
android:layout_height="match_parent" >
<com.chunk.customviewsdemo.views.ArcImageView.ArcImageView
android:id="@+id/aiv_one"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:BACkground="@drawable/steak"
custom:drawStyle="RIGHT_BOTTOM"
custom:drawStr="牛排"
custom:arcAlpha=""
custom:arcColor="@color/gray"
custom:textColor="@color/black"
custom:textSize="sp" />
</RelativeLayout>
<RelativeLayout
android:layout_width="dp"
android:layout_weight=""
android:layout_height="match_parent" >
<com.chunk.customviewsdemo.views.ArcImageView.ArcImageView
android:id="@+id/aiv_two"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:BACkground="@drawable/seafood"
custom:drawStyle="LEFT_BOTTOM"
custom:drawStr="海鲜"
custom:arcAlpha=""
custom:arcColor="@color/gray"
custom:textColor="@color/black"
custom:textSize="sp" />
</RelativeLayout>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="dp"
android:layout_weight=""
android:orientation="horizontal" >
<RelativeLayout
android:layout_width="dp"
android:layout_weight=""
android:layout_height="match_parent" >
<com.chunk.customviewsdemo.views.ArcImageView.ArcImageView
android:id="@+id/aiv_three"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:BACkground="@drawable/cheese"
custom:drawStyle="RIGHT_TOP"
custom:drawStr="奶酪"
custom:arcAlpha=""
custom:arcColor="@color/gray"
custom:textColor="@color/black"
custom:textSize="sp" />
</RelativeLayout>
<RelativeLayout
android:layout_width="dp"
android:layout_weight=""
android:layout_height="match_parent" >
<com.chunk.customviewsdemo.views.ArcImageView.ArcImageView
android:id="@+id/aiv_four"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:BACkground="@drawable/barbecue"
custom:drawStyle="LEFT_TOP"
custom:drawStr="烧烤"
custom:arcAlpha=""
custom:arcColor="@color/gray"
custom:textColor="@color/black"
custom:textSize="sp" />
</RelativeLayout>
</LinearLayout>
</LinearLayout>