Android开发笔记（九十九）圆形转盘

		removeAllViews();
		addView(mImageView);
		requestLayout();

		int mode = MeasureSpec.EXACTLY;
		int makeMeasureSpec = MeasureSpec.makeMeasureSpec(300, mode);
		mImageView.measure(makeMeasureSpec, makeMeasureSpec);

		if (mImageView != null) {
			//这里要设置子控件的位置,另外子控件的位置为相对位置不是绝对位置
			mImageView.layout(0, 0, 500, 500);
		}

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;

public class RotateTextView extends View {

	private Context mContext;
	private Paint mTextPaint;
	private String mText;
	private int mDegree;

	public RotateTextView(Context context) {
		this(context, null);
	}
	
	public RotateTextView(Context context, AttributeSet attrs) {
		super(context, attrs);
		mContext = context;
		mTextPaint = new Paint();
		mTextPaint.setColor(0xFF000000);
		mTextPaint.setTextSize(35);
	}

	@SuppressLint("DrawAllocation")
	@Override
	protected void onDraw(Canvas canvas) {
		Path path = new Path();
		RectF oval = new RectF(50, 50, 300, 300);
		path.addArc(oval, mDegree, mDegree+60);
		canvas.drawTextOnPath(mText, path, 0, 0, mTextPaint);
	}

	public void setDegree(String text, int degree) {
		mText = text;
		mDegree = degree;
		postInvalidate();
	}

}

import com.example.exmturntable.util.BitmapUtil;
import com.example.exmturntable.util.MetricsUtil;

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.os.Build;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;

public class RotateImageView extends ViewGroup {

	private final static String TAG = "RotateImageView";
	private Context mContext;
	private ImageView mImageView;
	private int dip_50;
	
	public RotateImageView(Context context) {
		this(context, null);
	}

	public RotateImageView(Context context, AttributeSet attrs) {
		super(context, attrs);
		mContext = context;
		dip_50 = MetricsUtil.dip2px(mContext, 50);
	}
	
	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);
//		设置测量尺寸
//		int mode = MeasureSpec.EXACTLY;
//		int makeMeasureSpec = MeasureSpec.makeMeasureSpec(300, mode);
//		mImageView.measure(makeMeasureSpec, makeMeasureSpec);
//		Log.d(TAG, "onMeasure getMeasuredWidth()="+mImageView.getMeasuredWidth()+", onMeasure getMeasuredHeight()="+mImageView.getMeasuredHeight());
	}

	@Override
	protected void onLayout(boolean changed, int l, int t, int r, int b) {
		if (mImageView != null) {
			//这里要设置子控件的位置,另外子控件的位置为相对位置不是绝对位置
			mImageView.layout(0, 0, 500, 500);
		}
	}
	
	@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
	public void setDegree(int img_res, int degree, int type) {
		removeAllViews();
		mImageView = new ImageView(mContext);
		Bitmap bitmap;
		if (type == 0) {
			bitmap = BitmapUtil.getRotateBitmap(
					BitmapFactory.decodeResource(getResources(), img_res), degree%360);
		} else {
			bitmap = BitmapUtil.getRotateBitmap2(
					BitmapFactory.decodeResource(getResources(), img_res), degree%360);
		}
		mImageView.setVisibility(View.VISIBLE);
		mImageView.setImageBitmap(bitmap);
		mImageView.setScaleType(ScaleType.FIT_CENTER);
		mImageView.setPadding(0, dip_50, dip_50, dip_50);
		addView(mImageView);
		
		requestLayout();
	}

	public static Bitmap getRotateBitmap(Bitmap b, float rotateDegree) {
		Matrix matrix = new Matrix();
		matrix.postRotate((float)rotateDegree);
		Bitmap rotaBitmap = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), matrix, false);
		return rotaBitmap;
	}

	public static Bitmap getRotateBitmap2(Bitmap bm, float rotateDegree) {
		Matrix m = new Matrix();
		m.setRotate(rotateDegree, (float)bm.getWidth()/2, (float)bm.getHeight()/2);
		Bitmap bm_new = Bitmap.createBitmap(bm.getHeight(), bm.getWidth(), Bitmap.Config.ARGB_8888);
		Paint paint = new Paint();
		Canvas canvas = new Canvas(bm_new);
		canvas.drawBitmap(bm, m, paint);
		return bm_new;
	}

}