android ImageView适配宽度 android设置imageview

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香奈儿 2024-08-19 12:11:21

文章标签 android 算法 bundle 宽高 ide 文章分类 Android 移动开发

.getDisplayMetrics()));// 默认为10dp
type = a.getInt(R.styleable.RoundImageView_type, TYPE_CIRCLE);// 默认为Circle
a.recycle();
}
/**
• 关于view的宽高:主要用于当设置类型为圆形时，我们强制让view的宽和高一致
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Log.e(“TAG”, “onMeasure”);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
/**
• 如果类型是圆形，则强制改变view的宽高一致，以小值为准;如果是圆角则不用管宽高问题
*/
if (type == TYPE_CIRCLE) {
mWidth = Math.min(getMeasuredWidth(), getMeasuredHeight());
mRadius = mWidth / 2;
setMeasuredDimension(mWidth, mWidth);
}
}
/**
1. 设置BitmapShader
2. 绘制
*/
@Override
protected void onDraw(Canvas canvas) {
if (getDrawable() == null) {
return;
}
setUpShader();
if (type == TYPE_ROUND) {
canvas.drawRoundRect(mRoundRect, mBorderRadius, mBorderRadius,
mBitmapPaint);
} else {
canvas.drawCircle(mRadius, mRadius, mRadius, mBitmapPaint);
// drawSomeThing(canvas);
}
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
// 圆角图片的范围
if (type == TYPE_ROUND)
mRoundRect = new RectF(0, 0, getWidth(), getHeight());
}
/**
• 初始化BitmapShader//给paint附加一个具有某种魔力(缩放)的shader
1. drawable转化为我们的bitmap
2. 设置shader 的mode
3. 设置scale: 因为最终缩放完成的图片一定要大于我们的view的区域
4. scale设置给matrix
5. matrix设置给shader
6. shader设置给paint
*/
private void setUpShader() {
Drawable drawable = getDrawable();
if (drawable == null) {
return;
}
Bitmap bmp = drawableToBitamp(drawable);
// 将bmp作为着色器，就是在指定区域内绘制bmp;此构造方法用的是拉伸mode: clamp
mBitmapShader = new BitmapShader(bmp, CLAMP, CLAMP);
float scale = 1.0f;
if (type == TYPE_CIRCLE) {
// 拿到bitmap宽或高的小值//我们需要画正方形
int bSize = Math.min(bmp.getWidth(), bmp.getHeight());
scale = mWidth * 1.0f / bSize;
} else if (type == TYPE_ROUND) {
// 如果图片的宽或者高与view的宽高不匹配，计算出需要缩放的比例；缩放后的图片的宽高，一定要大于我们view的宽高；所以我们这里取大值；//view的宽度/bitmap的宽度=缩放倍数
scale = Math.max(getWidth() * 1.0f / bmp.getWidth(), getHeight()
• 1.0f / bmp.getHeight());
}
// shader的变换矩阵，我们这里主要用于放大或者缩小
mMatrix.setScale(scale, scale);
// 设置变换矩阵
mBitmapShader.setLocalMatrix(mMatrix);
// 先给paint设置shader;然后画笔会有所不同哦,例如
mBitmapPaint.setShader(mBitmapShader);
}
/**
• drawable转bitmap
• 
• @param drawable
• @return
*/
private Bitmap drawableToBitamp(Drawable drawable) {
if (drawable instanceof BitmapDrawable) {
BitmapDrawable bd = (BitmapDrawable) drawable;
return bd.getBitmap();
}
//以下为drawable转bitmap的通用方法
int w = drawable.getIntrinsicWidth();
int h = drawable.getIntrinsicHeight();
Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, w, h);
drawable.draw(canvas);
return bitmap;
}
/**
• 添加一个方法
• bitmap转drawable
*/
private Drawable bitmapToDrawable(Bitmap bitmap) {
Drawable drawable = new BitmapDrawable(null, bitmap);
return drawable;
}
//状态存储与恢复
private static final String STATE_INSTANCE = “state_instance”;
private static final String STATE_TYPE = “state_type”;
private static final String STATE_BORDER_RADIUS = “state_border_radius”;
@Override
protected Parcelable onSaveInstanceState() {
Bundle bundle = new Bundle();
bundle.putParcelable(STATE_INSTANCE, super.onSaveInstanceState());
bundle.putInt(STATE_TYPE, type);
bundle.putInt(STATE_BORDER_RADIUS, mBorderRadius);
return bundle;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (state instanceof Bundle) {
Bundle bundle = (Bundle) state;
super.onRestoreInstanceState(((Bundle) state)
.getParcelable(STATE_INSTANCE));
this.type = bundle.getInt(STATE_TYPE);
this.mBorderRadius = bundle.getInt(STATE_BORDER_RADIUS);
} else {
super.onRestoreInstanceState(state);
}
}
/**
• 动态修改圆角大小
• */
public void setBorderRadius(int borderRadius) {
int pxVal = dp2px(borderRadius);
if (this.mBorderRadius != pxVal) {
this.mBorderRadius = pxVal;
invalidate();
}
}
/**
• 动态设置type
• */
public void setType(int type) {
if (this.type != type) {
this.type = type;
if (this.type != TYPE_ROUND && this.type != TYPE_CIRCLE) {
this.type = TYPE_CIRCLE;
}
requestLayout();
}
}
private int dp2px(int dpVal) {
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
dpVal, getResources().getDisplayMetrics());
}