public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
}
我知道我可以創建一個類
public class DrawView extends View {
Paint paint = new Paint();
public DrawView(Context context) {
super(context);
paint.setColor(Color.BLACK);
}
@Override
public void onDraw(Canvas canvas) {
canvas.drawLine(0, 0, 20, 20, paint);
canvas.drawLine(20, 0, 0, 20, paint);
}
}
而且在活動
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
drawView = new DrawView(this);
drawView.setBackgroundColor(Color.WHITE);
setContentView(drawView);
}
使用它,但它必須更換我原來的佈局setContentView(R.layout.activity_main);
如果我使用佈局,我不能畫東西我畫了一些東西,我不能使用佈局
我該如何保持兩個?
這是行不通的。如果我刪除3rd-4th構造函數,並將this(context,attrs,0);改爲'super(context,attrs,0);',那麼它將工作 –