特点

支持多行水印，支持自定义角度，支持自定义文字大小。

原理：

使用一个TextView 占据整个页面。在TextView基础上面打水印。

用法：

具体的view在

package cn.fulushan.watermark.view;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.ColorFilter;

import android.graphics.Paint;

import android.graphics.PixelFormat;

import android.graphics.drawable.Drawable;

import android.support.annotation.IntRange;

import android.support.annotation.NonNull;

import android.support.annotation.Nullable;

import java.util.List;

/**

* Created by fulushan on 18/4/5.

*/

public class WaterMarkBg extends Drawable {

private Paint paint = new Paint();

private List 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 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.parseColor("#40F3F5F9"));

paint.setColor(Color.parseColor("#50AEAEAE"));

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;

}

public static int sp2px(Context context, float spValue) {

final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;

return (int) (spValue * fontScale + 0.5f);

}

}

具体的用法

public class MainActivity extends AppCompatActivity {

private TextView bg_tv;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

bg_tv = findViewById(R.id.bg_tv);

SimpleDateFormat createTimeSdf1 = new SimpleDateFormat("yyyy-MM-dd");

List labels = new ArrayList<>();

labels.add("用户名：张三");

labels.add("日期："+ createTimeSdf1.format(new Date()));

labels.add("不可扩散");

bg_tv.setBackgroundDrawable(new WaterMarkBg(MainActivity.this,labels,-30,13));

}

}

效果图

github源码地址

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。