ch11.rar

package com.ehappy.extrycatch; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.view.Gravity; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends AppCompatActivity { private EditText edtX,edtY; private TextView txtResult; private Button btnDo; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 取得介面元件 id edtX=(EditText)findViewById(R.id.edtX); edtY=(EditText)findViewById(R.id.edtY); txtResult=(TextView)findViewById(R.id.txtResult); btnDo=(Button)findViewById(R.id.btnDo); // 設定 button 元件 的 listener 為 btnDoListener btnDo.setOnClickListener(btnDoListener); } // 定義 onClick() 方法 private Button.OnClickListener btnDoListener=new Button.OnClickListener(){ public void onClick(View v){ try { int x=Integer.parseInt(edtX.getText().toString()); int y=Integer.parseInt(edtY.getText().toString()); int r= x % y; txtResult.setText(x + " % " + y + " = " + r); } catch (NumberFormatException err){ Toast toast = Toast.makeText(getApplicationContext(), "發生輸入非數值的錯誤!", Toast.LENGTH_SHORT); toast.setGravity(Gravity.CENTER, 0, 0); toast.show(); } catch (Exception err){ Toast toast = Toast.makeText(getApplicationContext(), "發生其他的錯誤,，包括 分母為 0 的錯誤!\n\r錯誤資訊：" + err.toString(), Toast.LENGTH_SHORT); toast.setGravity(Gravity.CENTER, 0, 0); toast.show(); } finally{ Toast.makeText(getApplicationContext(), "finally 中一律執行!", Toast.LENGTH_SHORT).show(); } } }; }