自定義View解析
阿新 • • 發佈:2018-12-21
首先我們先介紹組合View:
public class MyXHView extends LinearLayout {
private EditText mEditText;
private TextView mCancel;
public MyXHView(Context context, AttributeSet attrs) { super(context, attrs); LayoutInflater.from(context).inflate(R.layout.header_view, this); mEditText = findViewById(R.id.Search_Edit); mCancel = findViewById(R.id.Cancel_Text); } public String getEditStr() { return mEditText.getText().toString(); } public TextView getmCancel() { return mCancel; }
}
ball:
public class BallView extends View {
private Paint paint; Context context; //圓的初始位置座標 private int x = 38; private int y = 38; private int radius = 35; //圓半徑 public BallView(Context context, AttributeSet attrs) { super(context, attrs); this.context = context; } /** * 實現onDraw()方法實現繪圖操作 * * @param canvas */ @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); //用canvas將螢幕設為白色 canvas.drawColor(Color.WHITE); //設定畫筆顏色為紅色 paint = new Paint(); paint.setColor(Color.RED); //設定消除鋸齒 paint.setAntiAlias(true); //使用畫筆繪製圓為小球 //x :圓心的x座標 //y :圓心的y座標 //radius :圓的半徑 //paint :畫筆 canvas.drawCircle(x, y, radius, paint); } //實現onTouchEvent方法,處理觸控事件 @Override public boolean onTouchEvent(MotionEvent event) { //判斷觸控點 switch (event.getAction()) { //實現MotionEvent.ACTION_DOWN,記錄按下的x,y座標:getRawX()和getRawY()獲得的是相對螢幕的位置 case MotionEvent.ACTION_DOWN: x = (int) event.getX(); y = (int) event.getY(); System.out.println("按下時: " + "x座標:" + event.getRawX() + " " + "y座標:" + event.getRawY()); //實現MotionEvent.ACTION_MOVE 記錄移動的x,y座標:getRawX()和getRawY()獲得的是相對螢幕的位置 case MotionEvent.ACTION_MOVE: x = (int) event.getX(); y = (int) event.getY(); System.out.println("移動時: " + "x座標:" + event.getRawX() + " " + "y座標:" + event.getRawY()); //實現MotionEvent.ACTION_UP 記錄擡起的x,y座標 case MotionEvent.ACTION_UP: // 獲取當前觸控點的x,y座標,為X軸和Y軸座標重新賦值:getX()和getY()獲得的永遠是view的觸控位置座標 x = (int) event.getX(); y = (int) event.getY(); System.out.println("擡起時: " + "x座標:" + event.getRawX() + " " + "y座標:" + event.getRawY()); break; } //獲取螢幕寬高 WindowManager manager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); int width = manager.getDefaultDisplay().getWidth(); int height = manager.getDefaultDisplay().getHeight(); //修正圓點座標,重新繪製圓 ,控制小球不會被移出螢幕 if (x >= 18 && y >= 18 && x <= width - 18 && y <= height - 18) { /** * Android提供了Invalidate方法實現介面重新整理,但是Invalidate不能直接線上程中呼叫,因為他是違背了單執行緒模型: 1. Android UI操作並不是執行緒安全的,並且這些操作必須在UI執行緒中呼叫。 invalidate()是用來重新整理View的,必須是在UI執行緒中進行工作。比如在修改某個view的顯示時,呼叫invalidate()才能看到重新繪製的介面。invalidate()的呼叫是把之前的舊的view從主UI執行緒佇列中pop掉。 2.Android 程式預設情況下也只有一個程序,但一個程序下卻可以有許多個執行緒。在這麼多執行緒當中,把主要是負責控 制UI介面的顯示、更新和控制元件互動的執行緒稱為UI執行緒,由於onCreate()方法是由UI執行緒執行的,所以也可以把UI執行緒理解 為主執行緒。其餘的執行緒可以理解為工作者執行緒。invalidate()得在UI執行緒中被調動,在工作者執行緒中可以通過Handler來通 知UI執行緒進行介面更新。而postInvalidate()在工作者執行緒中被呼叫。 */ //使用 postInvalidate()方法實現重繪小球,跟隨手指移動
// postInvalidate();
postInvalidate();
}
/*
* 備註:此處一定要將return super.onTouchEvent(event)修改為return true,原因是:
* 1)父類的onTouchEvent(event)方法可能沒有做任何處理,但是返回了false。
* 2)一旦返回false,在該方法中再也不會收到MotionEvent.ACTION_MOVE及MotionEvent.ACTION_UP事件。
*/
//return super.onTouchEvent(event);
return true;
}
}
每點選一次+1:
public class CounterView extends View implements View.OnClickListener {
private Paint mPaint;
private Rect mRect;
// 計數值,每點選一次本控制元件,其值增加1
private int mCount;
public CounterView(Context context, AttributeSet attrs) {
super(context, attrs);
mPaint = new Paint();
mRect = new Rect();
setOnClickListener(this);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
mPaint.setColor(Color.RED);
canvas.drawRect(0, 0, getWidth(), getHeight(), mPaint);
String text = String.valueOf(mCount);
mPaint.setColor(Color.YELLOW);
mPaint.setTextSize(50);
mPaint.getTextBounds(text, 0, text.length(), mRect);
int width = mRect.width();
int height = mRect.height();
canvas.drawText(text, getWidth() / 2 - width / 2, getHeight() / 2 + height / 2, mPaint);
Log.e("getWidth", getWidth() + "");
Log.e("getHeight", getHeight() + "");
Log.e("height", height + "");
}
@Override
public void onClick(View v) {
mCount++;
invalidate();
}
}
畫環畫圓 myView:
先在values建立xml檔案:
<attr name="textSize" format="dimension" />
<attr name="text" format="string" />
<attr name="circleColor" format="color" />
<attr name="arcColor" format="color" />
<attr name="textColor" format="color" />
<attr name="startAngle" format="integer" />
<attr name="sweepAngle" format="integer" />
</declare-styleable>
然後在佈局中:
android:layout_width="match_parent"
android:layout_height="match_parent"
app:startAngle="0"
app:sweepAngle="270"
app:text="hehe"
app:textSize="30sp"
app:textColor="@color/colorPrimaryDark"
app:circleColor="@color/colorPrimary"
app:arcColor="@color/colorAccent"
- 自己在value資料夾下新建attrs檔案 就可以在它裡面定義自己想要的屬性了
- 咱們自定義View初始化的東西要放到建構函式之後執行
- 因為我們自己寫的View執行順序
- 1:構造方法
- 2:測量
*/
public class MyView extends View {
private String text;
private int circleColor;
private int arcColor;
private int textColor;
private float textSize;
private int startAngle;
private int sweepAngle;
private int mCircleXY;
private float mRadius;
private Paint mCirclePaint;
private RectF mRectF;
private Paint mArcPaint;
private Paint mTextPaint;
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
//得到我們自己定義的屬性集合
TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.MyView);
if (ta != null) {
//兩個引數 引數1:R.styleable.MyView_circleColor 代表的咱們自己定義屬性集合
//引數2:如果你在佈局檔案裡面沒有新增定義的屬性 就給一個預設值
circleColor = ta.getColor(R.styleable.MyView_circleColor, 0);
arcColor = ta.getColor(R.styleable.MyView_arcColor, 0);
textColor = ta.getColor(R.styleable.MyView_textColor, 0);
textSize = ta.getDimension(R.styleable.MyView_textSize, 50);
text = ta.getString(R.styleable.MyView_text);
startAngle = ta.getInt(R.styleable.MyView_startAngle, 0);
sweepAngle = ta.getInt(R.styleable.MyView_sweepAngle, 90);
ta.recycle();
Log.e("text", text);
}
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
drawSth(canvas);
}
private void drawSth(Canvas canvas) {
init();
canvas.drawCircle(mCircleXY, mCircleXY, mRadius, mCirclePaint);
canvas.drawArc(mRectF, startAngle, sweepAngle, false, mArcPaint);
canvas.drawText(text, 0, text.length(), mCircleXY, mCircleXY + textSize
/ 4, mTextPaint);
}
private void init() {
//getWidth() 得到當前這個空間寬和高
int length = Math.min(getWidth(), getHeight());
Log.e("看看寬和高", "寬度:" + getWidth() + "高度:" + getHeight());
mCircleXY = length / 2;
mRadius = length * 0.5f / 2;
mCirclePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mCirclePaint.setColor(circleColor);
mRectF = new RectF(length * 0.1f, length * 0.1f, length * 0.9f,
length * 0.9f);
mArcPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mArcPaint.setColor(arcColor);
mArcPaint.setStyle(Paint.Style.STROKE);
mArcPaint.setStrokeWidth((getWidth() * 0.1f));
mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mTextPaint.setTextSize(textSize);
mTextPaint.setColor(textColor);
mTextPaint.setTextAlign(Paint.Align.CENTER);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
Log.e("onMeasure", "onMeasure");
}
}