Android通过画线实现button效果

package com.min.androidtest; import android.app.Activity; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Rect; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.ViewGroup.LayoutParams; import android.widget.Button; import android.widget.LinearLayout; public class AndroidTest extends Activity { private static final String TAG = "AndroidTest"; private static LinearLayout ll; private Button mBtn; private MyView mMyView; private boolean mbClickFlg = false; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // setContentView(R.layout.main); // 设置画面布局 ll = new LinearLayout(this.getBaseContext()); ll.setOrientation(LinearLayout.VERTICAL); // button mBtn = new Button(this.getBaseContext()); mBtn.setText("Draw"); // mBtn.setTextColor(0xff000000); mBtn.setTextSize(16); LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); lp.topMargin = 5; lp.leftMargin = 5; ll.addView(mBtn, lp); // 设置画图view LinearLayout.LayoutParams lp1 = new LinearLayout.LayoutParams( LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT); lp1.weight = 1; Rect rect = new Rect(10, 40, 90, 66); mMyView = new MyView(this.getBaseContext(), rect); mMyView.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { // TODO Auto-generated method stub Log.d(TAG, "mMyView clicked."); if (mbClickFlg) { mMyView.setStrText("Click Me"); } else { mMyView.setStrText("Again..."); } mbClickFlg = !mbClickFlg; mMyView.postInvalidate(); } }); ll.addView(mMyView, lp1); setContentView(ll); // 设置监听按钮点击事件 mBtn.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { // TODO Auto-generated method stub mMyView.drawLine(); mMyView.postInvalidate(); } }); } // 自定义画图类，继承自View类 public class MyView extends View { private Paint paint; private boolean bDrawLineFlg = false; private Rect mRect; private String mStrText = "having"; MyView(Context context) { super(context); // 生成paint paint = new Paint(); } MyView(Context context, Rect rect) { super(context); // 生成paint paint = new Paint(); mRect = rect; } @Override protected void onDraw(Canvas canvas) { // TODO Auto-generated method stub super.onDraw(canvas); // 填充整个画布 canvas.drawColor(Color.GRAY); // canvas.drawRGB(255, 255, 255); // 也可以 // 画图 if (bDrawLineFlg) { Log.d(TAG, "drawing"); // Draw top 6 lines paint.setColor(0xFFFFC0CB); canvas.drawLine(mRect.left + 2, mRect.top, mRect.right - 2, mRect.top, paint); canvas.drawLine(mRect.left + 1, mRect.top + 1, mRect.right -1, mRect.top + 1, paint); for (int i = 2; i < 6; i++) { canvas.drawLine(mRect.left, mRect.top + i, mRect.right, mRect.top + i, paint); } // Draw middle 14 lines paint.setColor(0xFFFFB6C1); for (int i = 6; i < 20; i++) { canvas.drawLine(mRect.left, mRect.top + i, mRect.right, mRect.top + i, paint); } // Draw bottom 6 lines paint.setColor(0xFFFFC0CB); for (int i = 20; i < 24; i++) { canvas.drawLine(mRect.left, mRect.top + i, mRect.right, mRect.top + i, paint); } canvas.drawLine(mRect.left + 1, mRect.top + 24, mRect.right - 1, mRect.top + 24, paint); canvas.drawLine(mRect.left + 2, mRect.top + 25, mRect.right - 2, mRect.top + 25, paint); // draw text paint.setColor(0xFF0000FF); paint.setTextSize(16); paint.setAntiAlias(true); // 消除锯齿 paint.setFlags(Paint.ANTI_ALIAS_FLAG); // 消除锯齿 try{ float widths[] = new float[mStrText.length()]; paint.getTextWidths(mStrText, widths); float textWidth = 0.0f; for(int i = 0; i < widths.length; i++) { textWidth += widths[i]; Log.d(TAG, "widths[0] = " + widths[i]); } Log.d(TAG, "textWidth = " + textWidth); float textSize = paint.getTextSize(); Log.d(TAG, "textSize = " + textSize); canvas.drawText(mStrText, mRect.left + (mRect.width() - textWidth) / 2, mRect.bottom - (mRect.height() - textSize) / 2 - 3, // add offset to y position paint); } catch(Exception e) { e.printStackTrace(); } } } public void drawLine() { // 设置画线标志 bDrawLineFlg = !bDrawLineFlg; if (bDrawLineFlg) { mBtn.setText("Hide"); } else { mBtn.setText("Draw"); } Log.d(TAG, "to be draw"); } public void setStrText(String text) { mStrText = text; } } }

 

效果如图：