進行中のスキャンが進行中であることを表示するにはどうすればいいですか？

Question

私はアンドロイドアプリケーションからカメラを開いている間、画面を前後に移動する線を表示したいと思います。 （バーコードスキャナアプリケーションで動く線のように）。このためLike the white line shown in the image. The line can move from top to bottom and bottom to top continuously

Answer 1

、あなたはつもりだカスタムビューを作成し、以下のようonDrawメソッドをオーバーライドしたい：

public class MyScanningView extends View { 
private Paint paint = new Paint(); 
private int mPosY = 0; 
private boolean runAnimation = true; 
private boolean showLine = true; 
private Handler handler; 
private Runnable refreshRunnable; 
private boolean isGoingDown = true; 
private int mHeight; 

public MyScanningView(Context context) { 
    super(context); 
    init(); 
} 

public MyScanningView(Context context, AttributeSet attrs) { 
    super(context, attrs); 
    init(); 
} 

public MyScanningView(Context context, AttributeSet attrs, int defStyleAttr) { 
    super(context, attrs, defStyleAttr); 
    init(); 
} 

private void init() { 
    paint.setColor(Color.WHITE); 
    //Add anything else you want to customize your line, like the stroke width 
    handler = new Handler(); 
    runnable = new Runnable() { 
         @Override 
         public void run() { 
          refreshView(); 
         } 
        } 
} 

@Override 
public void onDraw(Canvas canvas) { 
    mHeight = canvas.getHeight(); 
    if (showLine) { 
     canvas.drawLine(0, mPosY, canvas.getWidth(), mPosY, paint); 
    } 
    if (runAnimation) { 
     handler.postDelayed(refreshRunnable, DELAY); 
    } 
} 

public void startAnimation() { 
    runAnimation = true; 
    showLine = true; 
    this.invalidate(); 
} 

public void stopAnimation() { 
    runAnimation = false; 
    showLine = false; 
    reset(); 
    this.invalidate(); 
} 

private void reset() { 
    mPosY = 0; 
    isGoingDown = true; 
} 

private void refreshView() { 
    //Update new position of the line 
    if (isGoingDown) { 
    mPosY += 5; 
    if (mPosY > mHeight) { 
     //We invert the direction of the animation 
     mPosY = mHeight; 
     isGoingDown = false; 
    } else { 
    mPosY -= 5; 
    if (mPosY < 0) { 
     //We invert the direction of the animation 
     mPosY = 0; 
     isGoingDown = true; 
    } 
this.invalidate(); 
} 

} 

そして、単にあなたのactivy_main.xmlにこのビューを追加します。

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout 
android:id="@+id/main_layout" 
xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent"> 
    <com.//wherever_is_your_view.MyScanningView 
    android:id="@+id/scanningView" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" /> 
</LinearLayout> 

そして、あなたのMainActivityで：

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    MyScanningView scanningView = (MyScanningView) findViewById(R.id.scanningView); 
} 

Answer 2

以下のコードを使用して、xmlでそのビューを作成し、drawlineメソッドのスキャンの制限を制限します。 ScanningIndicatorのobject.startAnimation（）を使用してアニメーションを開始します。

public class ScanningIndicator extends View { 
private Paint paint = new Paint(); 
private int mPosY = 0; 
private boolean runAnimation = true; 
private boolean showLine = true; 
private Handler handler; 
private Runnable refreshRunnable; 
private boolean isGoingDown = true; 
private int mHeight; 

public ScanningIndicator(Context context) { 
    super(context); 
    init(); 
} 

public ScanningIndicator(Context context, AttributeSet attrs) { 
    super(context, attrs); 
    init(); 
} 

public ScanningIndicator(Context context, AttributeSet attrs, int defStyleAttr) { 
    super(context, attrs, defStyleAttr); 
    init(); 
} 

private void init() { 
    paint.setColor(Color.RED); 
    paint.setStrokeWidth(5.0f); 
    //Add anything else you want to customize your line, like the stroke width 
    handler = new Handler(); 
    refreshRunnable = new Runnable() { 
     @Override 
     public void run() { 
      refreshView(); 
     } 
    }; 
} 

@Override 
public void onDraw(Canvas canvas) { 
    mHeight = canvas.getHeight(); 
    if (showLine) { 
     canvas.drawLine(0, mPosY, canvas.getWidth(), mPosY, paint); 
    } 
    if (runAnimation) { 
     handler.postDelayed(refreshRunnable, 0); 
    } 
} 

public void startAnimation() { 
    runAnimation = true; 
    showLine = true; 
    this.invalidate(); 
} 

public void stopAnimation() { 
    runAnimation = false; 
    showLine = false; 
    reset(); 
    this.invalidate(); 
} 

private void reset() { 
    mPosY = 0; 
    isGoingDown = true; 
} 

private void refreshView() { 
    //Update new position of the line 
    if (isGoingDown) { 
     mPosY += 5; 
     if (mPosY > mHeight) {    
      mPosY = mHeight; 
      isGoingDown = false; 
     } 
    } else { 
     //We invert the direction of the animation 
     mPosY -= 5; 
     if (mPosY < 0) { 
      mPosY = 0; 
      isGoingDown = true; 
     } 
    } 
    this.invalidate(); 
} 
}