自定义View 水印 前景色 [MD]
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|---|---|---|---|
| baiqiantao | baiqiantao | bqt20094 | baiqiantao@sina.com |
目录
自定义View 水印 前景色
第一种实现方式
可以在 BaseActivity 中将水印布局设为根布局
<com.bqt.lock.MarkFrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/mark_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:mark_is_foreground="false"
app:mark_show_value="包青天"
app:mark_textcolor="#fff">
<TextView
android:id="@+id/tv"
android:layout_width="match_parent"
android:layout_height="100dp"
android:background="#f00"
android:gravity="center"/>
<ImageView
android:layout_width="match_parent"
android:layout_height="100dp"
android:layout_marginTop="200dp"
android:scaleType="centerCrop"
android:src="@drawable/icon"/>
</com.bqt.lock.MarkFrameLayout>
自定义属性
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="MarkFrameLayout">
<attr name="mark_rotate_degrees" format="integer"/>
<attr name="mark_textcolor" format="color|reference"/>
<attr name="mark_textsize" format="dimension"/>
<attr name="mark_alpha" format="integer"/>
<attr name="mark_is_foreground" format="boolean"/>
<attr name="mark_hor_spacing" format="dimension"/>
<attr name="mark_ver_spacing" format="dimension"/>
<attr name="mark_show_value" format="string"/>
</declare-styleable>
</resources>
水印布局
绘制水印时，可以选择在onDrawForeground上绘制前景色(盖在所有View的上面)，也可以选择在onDraw上绘制背景色(会被所有View的背景遮盖)。
如果需要用到继承自其他其他 Layout 的水印布局，则只需将继承的类改为RelativeLayout或LinearLayout即可，其他什么都不需要更改。
public class MarkFrameLayout extends FrameLayout {
private static final int DEFAULT_DEGRESES = -15;//水印倾斜角度
private static final int DEFAULT_MARK_PAINT_COLOR = Color.parseColor("#FFCCCCCC");//水印颜色
private static final int DEFAULT_ALPHA = (int) (0.5 * 255);//水印透明度
private static final String DEFAULT_MARK_SHOW_VALUE = "[水印]";//水印内容
private boolean showMark = true;
private float mMarkTextSize;
private int mMarkTextColor;
private boolean mMarkLayerIsForeground; //水印绘制在控件背景上，还是前景色上
private float mDegrees;
private int mVerticalSpacing;
private int mHorizontalSpacing;
private int mMarkPainAlpha;
private String mMarkValue;
private TextPaint mMarkPaint;
private Bitmap mMarkBitmap;
public MarkFrameLayout(@NonNull Context context) {
this(context, null);
}
public MarkFrameLayout(@NonNull Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
if (showMark) {
int defaultMarkTextSize = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 12, getResources().getDisplayMetrics());
int defaultSpacing = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 24, getResources().getDisplayMetrics());
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MarkFrameLayout);
mDegrees = a.getInteger(R.styleable.MarkFrameLayout_mark_rotate_degrees, DEFAULT_DEGRESES);
mMarkTextColor = a.getColor(R.styleable.MarkFrameLayout_mark_textcolor, DEFAULT_MARK_PAINT_COLOR);
mMarkTextSize = a.getDimension(R.styleable.MarkFrameLayout_mark_textsize, defaultMarkTextSize);
mMarkPainAlpha = a.getInt(R.styleable.MarkFrameLayout_mark_alpha, DEFAULT_ALPHA);
mMarkLayerIsForeground = a.getBoolean(R.styleable.MarkFrameLayout_mark_is_foreground, true);//默认绘制在前景色上
mHorizontalSpacing = (int) a.getDimension(R.styleable.MarkFrameLayout_mark_hor_spacing, defaultSpacing);
mVerticalSpacing = (int) a.getDimension(R.styleable.MarkFrameLayout_mark_ver_spacing, defaultSpacing);
mMarkValue = a.getString(R.styleable.MarkFrameLayout_mark_show_value);
mMarkValue = TextUtils.isEmpty(mMarkValue) ? DEFAULT_MARK_SHOW_VALUE : mMarkValue;
a.recycle();
initWaterPaint();
setForeground(new ColorDrawable(Color.TRANSPARENT)); //重置前景色透明
}
}
@Override
public void onDrawForeground(Canvas canvas) {
super.onDrawForeground(canvas);
if (showMark && mMarkLayerIsForeground) {
drawMark(canvas); //绘制前景色
}
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (showMark && !mMarkLayerIsForeground) {
drawMark(canvas); //绘制被景色
}
}
private void initWaterPaint() {
//初始化Mark的Paint
mMarkPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG); //mMarkPaint.setAntiAlias(true)
mMarkPaint.setColor(mMarkTextColor);
mMarkPaint.setAlpha(mMarkPainAlpha);
mMarkPaint.setTextSize(mMarkTextSize);
//初始化MarkBitmap
Paint.FontMetrics fontMetrics = mMarkPaint.getFontMetrics();
int textHeight = (int) (fontMetrics.bottom - fontMetrics.top);
int textLength = (int) mMarkPaint.measureText(mMarkValue);
mMarkBitmap = Bitmap.createBitmap(textLength + 2 * mHorizontalSpacing,
textHeight + mVerticalSpacing * 2, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(mMarkBitmap);
canvas.drawText(mMarkValue, mHorizontalSpacing, mVerticalSpacing, mMarkPaint);
}
private void drawMark(Canvas canvas) {
int maxSize = Math.max(getMeasuredWidth(), getMeasuredHeight());
mMarkPaint.setShader(new BitmapShader(mMarkBitmap, Shader.TileMode.REPEAT, Shader.TileMode.REPEAT));
canvas.save();
canvas.translate(-(maxSize - getMeasuredWidth()) / 2, 0);
canvas.rotate(mDegrees, maxSize / 2, maxSize / 2);
canvas.drawRect(new RectF(0, 0, maxSize, maxSize), mMarkPaint);
canvas.restore();
}
public void setShowMark(boolean showMark) {
this.showMark = showMark;
invalidate();
}
}
第二种实现方式
支持多行水印，支持自定义角度，支持自定义文字大小。
使用案例
List<String> labels = new ArrayList<>();
labels.add("用户名：张三");
labels.add("日期：2021-6-14");
labels.add("不可扩散");
WaterMarkBg bgDrawable=new WaterMarkBg(this, labels, -10, 10);
FrameLayout rootView = findViewById(R.id.layout);
rootView.setForeground(bgDrawable);
TextView bg_tv = findViewById(R.id.bg_tv);
bg_tv.setBackgroundDrawable(bgDrawable);
自定义 Drawable
public class WaterMarkBg extends Drawable {
private Paint paint = new Paint();
private List<String> labels;
private Context context;
private int degress;//角度
private int fontSize;//字体大小 单位sp
/**
* 初始化构造
*
* @param context 上下文
* @param labels 水印文字列表 多行显示支持
* @param degress 水印角度
* @param fontSize 水印文字大小
*/
public WaterMarkBg(Context context, List<String> labels, int degress, int fontSize) {
this.labels = labels;
this.context = context;
this.degress = degress;
this.fontSize = fontSize;
}
@Override
public void draw(@NonNull Canvas canvas) {
int width = getBounds().right;
int height = getBounds().bottom;
canvas.drawColor(Color.TRANSPARENT);
paint.setColor(Color.GRAY);
paint.setAlpha((int) (0.5 * 255));
paint.setAntiAlias(true);
paint.setTextSize(sp2px(context, fontSize));
canvas.save();
canvas.rotate(degress);
float textWidth = paint.measureText(labels.get(0));
int index = 0;
for (int positionY = height / 10; positionY <= height; positionY += height / 10 + 80) {
float fromX = -width + (index++ % 2) * textWidth;
for (float positionX = fromX; positionX < width; positionX += textWidth * 2) {
int spacing = 0;//间距
for (String label : labels) {
canvas.drawText(label, positionX, positionY + spacing, paint);
spacing = spacing + 50;
}
}
}
canvas.restore();
}
@Override
public void setAlpha(@IntRange(from = 0, to = 255) int alpha) {
}
@Override
public void setColorFilter(@Nullable ColorFilter colorFilter) {
}
@Override
public int getOpacity() {
return PixelFormat.UNKNOWN;
}
private static int sp2px(Context context, float spValue) {
final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
return (int) (spValue * fontScale + 0.5f);
}
}
2018-10-13
本文来自博客园，作者：白乾涛，转载请注明原文链接：https://www.cnblogs.com/baiqiantao/p/9782665.html
