view的執行過程，各種方法的調用先後順序

這裏只是測試各個方法的執行流程，有些時候就是這些小基礎是非常重要的，下了測試代碼如下：

/** 
 * 自定義View的常用方法的調用先後順序 
 * Created by chengguo on 2016/3/18. 
 */  
public class CustomView extends View {  

    /** 
     * 用java代碼創建CustomView時調用此構成方法 
     * 
     * @param context 
     */  
    public CustomView(Context context) {  
        super(context);  
        Log.i("tag", "----  public CoustomView(Context context) ----");  
    }  

    /** 
     * 用佈局文件xml創建CustomView時調用此構成方法 
     * 
     * @param context 
     */  
    public CustomView(Context context, AttributeSet attrs) {  
        super(context, attrs);  
        Log.i("tag", "----  public CoustomView(Context context, AttributeSet attrs) ----");  
    }  

    public CustomView(Context context, AttributeSet attrs, int defStyleAttr) {  
        super(context, attrs, defStyleAttr);  
        Log.i("tag", "----  public CoustomView(Context context, AttributeSet attrs, int defStyleAttr) ----");  
    }  


    /** 
     * 使用佈局文件XML創建CustomView時，在xml文件加載完成後調用這個方法 
     */  
    @Override  
    protected void onFinishInflate() {  
        super.onFinishInflate();  
        Log.i("tag", "----  onFinishInflate() ----");  
    }  

    /** 
     * CustomView的大小發生改變時調用這個方法 
     * 
     * @param w 
     * @param h 
     * @param oldw 
     * @param oldh 
     */  
    @Override  
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {  
        super.onSizeChanged(w, h, oldw, oldh);  
        Log.i("tag", "----  onSizeChanged = " + " w = " + w + "  h = " + h + "  oldW = " + oldw + "  oldH = " + oldw);  
    }  

    /** 
     * 在畫布上面繪製 
     * 
     * @param canvas 
     */  
    @Override  
    protected void dispatchDraw(Canvas canvas) {  
        super.dispatchDraw(canvas);  
        Log.i("tag", "----  dispatchDraw = ");  
    }  

    /** 
     * 繪製CustomView時調用 
     * 
     * @param canvas 
     */  
    @Override  
    protected void onDraw(Canvas canvas) {  
        super.onDraw(canvas);  
        Log.i("tag", "----  onDraw ----");  
    }  

    /** 
     * 測量CustomView的大小 
     * 
     * @param widthMeasureSpec 
     * @param heightMeasureSpec 
     */  
    @Override  
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {  
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);  
        Log.i("tag", "----  onMeasure ----");  
    }  

    /** 
     * 將CustomView放置到父容器中去 
     * 
     * @param changed 
     * @param left 
     * @param top 
     * @param right 
     * @param bottom 
     */  
    @Override  
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {  
        super.onLayout(changed, left, top, right, bottom);  
        Log.i("tag", "----  onLayout ----");  
    }  


    /** 
     * 將CustomView依附到Window中 
     */  
    @Override  
    protected void onAttachedToWindow() {  
        super.onAttachedToWindow();  
        Log.i("tag", "----  onAttachedToWindow ----");  
    }  

    /** 
     * 當手機屏幕從橫屏和豎屏 相互轉化時調用 
     * 
     * @param newConfig 
     */  
    @Override  
    protected void onConfigurationChanged(Configuration newConfig) {  
        super.onConfigurationChanged(newConfig);  
        Log.i("tag", "----  onConfigurationChanged ----");  
    }  

}  

---

下面是Log信息，如下：

03-18 11:32:30.198 14844-14844/? I/tag: ----  public CoustomView(Context context, AttributeSet attrs) ----  
03-18 11:32:30.198 14844-14844/? I/tag: ----  onFinishInflate() ----  
03-18 11:32:30.227 14844-14844/? I/tag: ----  onAttachedToWindow ----  
03-18 11:32:30.228 14844-14844/? I/tag: ----  onMeasure ----  
03-18 11:32:30.294 14844-14844/? I/tag: ----  onMeasure ----  
03-18 11:32:30.295 14844-14844/? I/tag: ----  onSizeChanged =  w = 1080  h = 135  oldW = 0  oldH = 0  
03-18 11:32:30.295 14844-14844/? I/tag: ----  onLayout ----  
03-18 11:32:30.310 14844-14844/? I/tag: ----  onMeasure ----  
03-18 11:32:30.310 14844-14844/? I/tag: ----  onLayout ----  
03-18 11:32:30.311 14844-14844/? I/tag: ----  onDraw ----  
03-18 11:32:30.311 14844-14844/? I/tag: ----  dispatchDraw =   

經過log測試，就知道了，View的方法的執行過程，那麼在自定義View的時候，就會在正確的方法中，進行操作。希望對大家有所幫助，原文鏈接