android实现文字水印 android实现文字水印效果 支持多行水印
fulushan的技术专栏 人气:1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<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.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<String> 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
加载全部内容