Android開發(fā)之圓角矩形創(chuàng)建工具RoundRect類定義與用法分析

2019-12-12 01:18:06

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供稿：網(wǎng)友

本文實例講述了Android開發(fā)之圓角矩形創(chuàng)建工具RoundRect類。分享給大家供大家參考，具體如下：

用于把普通圖片轉(zhuǎn)換為圓角圖像的工具類RoundRect類（復(fù)制即可使用）：

RoundRect.java

import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.PorterDuff;import android.graphics.PorterDuffXfermode;import android.graphics.RectF;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;public class RoundRect {  private int width;  private int height;  private float cornerRadius;  /**   * 用于初始化圓角矩形基本參數(shù)   *   * @param width    圖片寬度   * @param height    圖片高度   * @param cornerRadius 圓角半徑   */  public RoundRect(int width, int height, float cornerRadius) {    this.width = width;    this.height = height;    this.cornerRadius = cornerRadius;  }  /**   * 用于把普通圖片轉(zhuǎn)換為圓角矩形圖像   *   * @param path 圖片路徑   * @return output 轉(zhuǎn)換后的圓角矩形圖像   */  Bitmap toRoundRect(String path) {    //創(chuàng)建位圖對象    Bitmap photo = lessenUriImage(path);    return Transformation(photo);  }  /**   * 用于把普通圖片轉(zhuǎn)換為圓角矩形圖像   *   * @param imageID 圖片資源ID   * @param context 上下文對象   * @return output 轉(zhuǎn)換后的圓角矩形圖像   */  Bitmap toRoundRect(Context context, int imageID) {    //創(chuàng)建位圖對象    Bitmap photo = BitmapFactory.decodeResource(context.getResources(), imageID);    return Transformation(photo);  }  /**   * 用于把Uri圖片轉(zhuǎn)換為Bitmap對象   *   * @param path 圖片URI地址   * @return 生成的Bitmap對象   */  public final static Bitmap lessenUriImage(String path) {    BitmapFactory.Options options = new BitmapFactory.Options();    options.inJustDecodeBounds = true;    Bitmap bitmap = BitmapFactory.decodeFile(path, options); //此時返回 bm 為空    options.inJustDecodeBounds = false; //縮放比。由于是固定比例縮放，只用高或者寬其中一個數(shù)據(jù)進行計算即可    int be = (int) (options.outHeight / (float) 320);    if (be <= 0) be = 1;    options.inSampleSize = be; //重新讀入圖片，注意此時已經(jīng)把 options.inJustDecodeBounds 設(shè)回 false 了    bitmap = BitmapFactory.decodeFile(path, options);    int w = bitmap.getWidth();    int h = bitmap.getHeight();    System.out.println(w + " " + h); //after zoom    return bitmap;  }  /**   * 用于把Bitmap圖像轉(zhuǎn)換為圓角圖像   *   * @param photo 需要轉(zhuǎn)換的Bitmap對象   * @return 轉(zhuǎn)換成圓角的Bitmap對象   */  private Bitmap Transformation(Bitmap photo) {    //根據(jù)源文件新建一個darwable對象    Drawable imageDrawable = new BitmapDrawable(photo);    // 新建一個新的輸出圖片    Bitmap output = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);    Canvas canvas = new Canvas(output);    // 新建一個矩形    RectF outerRect = new RectF(0, 0, width, height);    // 產(chǎn)生一個紅色的圓角矩形    Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);    paint.setColor(Color.RED);    canvas.drawRoundRect(outerRect, cornerRadius, cornerRadius, paint);    // 將源圖片繪制到這個圓角矩形上    paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));    imageDrawable.setBounds(0, 0, width, height);    canvas.saveLayer(outerRect, paint, Canvas.ALL_SAVE_FLAG);    imageDrawable.draw(canvas);    canvas.restore();    return output;  }}

測試效果：

創(chuàng)建矩形圖標：

public class MainActivity extends Activity {  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.image);    ImageView image = (ImageView)findViewById(R.id.image);    RoundRect roundRect = new RoundRect(500,500,100);    Bitmap photo = roundRect.toRoundRect(this,R.drawable.kms);    image.setImageBitmap(photo);  }}

創(chuàng)建圓形頭像：

public class MainActivity extends Activity {  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.image);    ImageView image = (ImageView)findViewById(R.id.image);    RoundRect roundRect = new RoundRect(500,500,300);    Bitmap photo = roundRect.toRoundRect(this,R.drawable.indark);    image.setImageBitmap(photo);  }}