android自定义view1

2019-11-09 16:46:01

字体：大中小

来源：转载

供稿：网友

自定义viwe步骤1：自定义view属性2：在view的构造方法中获取我们自定义的属性3：重谢onmesure4：重谢ondraw自定义view属性在values 下面新建attrs

我们定义了字体，字体颜色，字体大小3个属性，format是值该属性的取值类型:

一共有：string,color,demension,integer,enum,reference,float,boolean,fraction,flag;

然后在布局中声明我们的自定义View创建我们需要自定义的类


	package tzq.customview.view;

	import android.content.Context;
	import android.content.res.TypedArray;
	import android.graphics.Canvas;
	import android.graphics.Color;
	import android.graphics.Paint;
	import android.graphics.Rect;
	import android.util.AttributeSet;
	import android.util.TypedValue;
	import android.view.View;

	import java.util.ArrayList;
	import java.util.List;
	import java.util.Random;

	import tzq.customview.R;



	public class MyCustomerView extends View {

	/**
	* 文本
	*/
	PRivate String mText;

	/**
	* 文本颜色
	*/
	private int mTextColor;

	/**
	* 文本字体大小
	*/
	private int mTextSize;


	private Paint mPaint;

	private Rect mBound;

	public MyCustomerView(Context context, AttributeSet attrs, int defStyleAttr) {
	super(context, attrs, defStyleAttr);


	}

	public MyCustomerView(Context context, AttributeSet attrs) {
	super(context, attrs);
	initView(context, attrs);
	}


	public MyCustomerView(Context context) {
	super(context);
	}

	private void initView(Context context, AttributeSet attrs) {

	TypedArray mTypedArray = context.obtainStyledAttributes(attrs, R.styleable.customstyle);
	int count = mTypedArray.getIndexCount();
	for (int attr = 0; attr < count; attr++) {
	switch (attr) {
	case R.styleable.customstyle_text:
	mText = mTypedArray.getString(attr);
	break;
	case R.styleable.customstyle_textColor:
	mTextColor = mTypedArray.getColor(attr, Color.BLACK);
	break;
	case R.styleable.customstyle_textSize:
	mTextSize = mTypedArray.getDimensionPixelSize(attr, (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));
	break;
	}
	}
	mTypedArray.recycle();
	mPaint = new Paint();
	mPaint.setTextSize(mTextSize);
	mPaint.setAntiAlias(true);
	mBound = new Rect();
	mPaint.getTextBounds(mText, 0, mText.length(), mBound);

	this.setOnClickListener(new View.OnClickListener() {

	@Override
	public void onClick(View v) {
	mText = createStringRadom();
	postInvalidate();
	}
	});

	}

	private String createStringRadom() {

	Random mRandom = new Random();
	List<Integer> listSize = new ArrayList<Integer>();

	while (listSize.size() < 4) {
	listSize.add(mRandom.nextInt(10));
	}

	StringBuilder mStringBuilder = new StringBuilder();

	for (int value : listSize) {
	mStringBuilder.append(value);
	}

	return mStringBuilder.toString();
	}

	@Override
	protected void onDraw(Canvas canvas) {
	super.onDraw(canvas);
	mPaint.setColor(Color.YELLOW);
	canvas.drawRect(0, 0, getMeasuredWidth(), getMeasuredHeight(), mPaint);
	mPaint.setColor(mTextColor);
	canvas.drawText(mText, getWidth() / 2 - mBound.width() / 2, getHeight() / 2 + mBound.height() / 2, mPaint);
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

	int widthSize = MeasureSpec.getSize(widthMeasureSpec);
	int widthModel = MeasureSpec.getMode(widthMeasureSpec);
	int heightSize = MeasureSpec.getSize(heightMeasureSpec);
	int heightModel = MeasureSpec.getMode(heightMeasureSpec);

	int width, height;
	if (widthModel == MeasureSpec.EXACTLY) {
	width = widthSize;
	} else {
	mPaint.setTextSize(mTextSize);
	mPaint.getTextBounds(mText, 0, mText.length(), mBound);
	float textWidth = mBound.width();
	int desiredWith = (int) (getPaddingLeft() + getPaddingRight() + textWidth);
	width = desiredWith;
	}

	if (heightModel == MeasureSpec.EXACTLY) {
	height = heightSize;
	} else {
	mPaint.setTextSize(mTextSize);
	mPaint.getTextBounds(mText, 0, mText.length(), mBound);
	float textHeight = mBound.height();
	int desiredHeight = (int) (getPaddingTop() + getPaddingBottom() + textHeight);
	height = desiredHeight;
	}

	setMeasuredDimension(width, height);
	}


	}如果需要制定view的大小需要重谢onmeasure方法获取当前model 和sizwExACTLY 父类视图确定子类视图的大小由SpecSize 的值确定对应Android:layoutWidth="";AT_MOST最大的值由父类specSize 确定，子类view 最大值不能大于父类确定值UNSPECIFIED 父用器不对view大小限制