package com.example.drawcircle; import android.app.Activity; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Paint.Style; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.MotionEvent; import android.view.View; import android.view.View.OnTouchListener; import android.widget.FrameLayout; public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); FrameLayout fm = (FrameLayout)findViewById(R.id.framelayout1); final DrawCircle drawview= new DrawCircle(this); drawview.setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View arg0, MotionEvent arg1) { // TODO Auto-generated method stub drawview.xpos=arg1.getX(); drawview.ypos=arg1.getY(); drawview.invalidate(); return false; } }); fm.addView(drawview); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } public class DrawCircle extends View { private float xpos,ypos; public DrawCircle(Context context) { super(context); xpos=100; ypos=100; // TODO Auto-generated constructor stub } protected void onDraw(Canvas canvas) { super.onDraw(canvas); Paint paint = new Paint(); paint.setColor(Color.BLUE); paint.setStyle(Style.STROKE);//填充样式为描边 paint.setStrokeWidth(1);//笔触宽度为5像素 canvas.drawCircle(xpos,ypos,50, paint); canvas.drawCircle(xpos,ypos,40, paint); canvas.drawCircle(xpos,ypos,30, paint); canvas.drawCircle(xpos,ypos,20, paint); canvas.drawCircle(xpos,ypos,10, paint); paint.setTextSize(20); canvas.drawText("这是一个地球！",xpos-50,ypos+100,paint); } } }
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/framelayout1" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.drawcircle.MainActivity" > </FrameLayout>
