5分钟
最简单的绘制圆形的ImageView
相信大家对圆形或者圆角的ImageView不陌生吧，现在很多的APP都很喜欢圆形的头像是吧~
这里就简单的写个圆形的ImageView吧，当然这只是一个示例，再不考虑性能与抗锯齿的情况下！！！
可以说是写来玩玩，实际项目的话可以考虑用Github上牛人写的控件，比如下面这两个：
git怎么玩前面已经教过大家了~把项目clone下来把相关文件复制到自己的项目即可~
代码示例：
运行效果图：
实现代码：
自定义ImageView：**RoundImageView.java
package com.jay.demo.imageviewdemo;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PaintFlagsDrawFilter;
import android.graphics.Path;
import android.graphics.Rect;
import android.graphics.Region;
import android.util.AttributeSet;
import android.widget.ImageView;
/**
* Created by coder-pig on 2015/7/18 0018.
*/
public class RoundImageView extends ImageView {
private Bitmap mBitmap;
private Rect mRect = new Rect();
private PaintFlagsDrawFilter pdf = new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG);
private Paint mPaint = new Paint();
private Path mPath=new Path();
public RoundImageView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
//传入一个Bitmap对象
public void setBitmap(Bitmap bitmap) {
this.mBitmap = bitmap;
}
private void init() {
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setFlags(Paint.ANTI_ALIAS_FLAG);
mPaint.setAntiAlias(true);// 抗锯尺
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(mBitmap == null)
{
return;
}
mRect.set(0,0,getWidth(),getHeight());
canvas.save();
canvas.setDrawFilter(pdf);
mPath.addCircle(getWidth() / 2, getWidth() / 2, getHeight() / 2, Path.Direction.CCW);
canvas.clipPath(mPath, Region.Op.REPLACE);
canvas.drawBitmap(mBitmap, null, mRect, mPaint);
canvas.restore();
}
}布局代码：activity_main.xml:
<com.jay.demo.imageviewdemo.RoundImageView
android:id="@+id/img_round"
android:layout_width="200dp"
android:layout_height="200dp"
android:layout_margin="5px"/>MainActivity.java:
package com.jay.demo.imageviewdemo;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
private RoundImageView img_round;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
img_round = (RoundImageView) findViewById(R.id.img_round);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),R.mipmap.meinv);
img_round.setBitmap(bitmap);
}
}本节讲解了ImageView(图像视图),内容看上很多，不过都是一些详述性的东西，知道即可~ 最后的自定义圆形ImageView也是，只是写来玩玩的，实际项目中还是建议使用那两个第三方的自定义控件吧~
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