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无法解析“OnSeekBarChangeListener”

android java

Wais Kamal · 技术社区 · 5 年前

我有一个搜索栏,调整后应该在文本视图中显示其当前值。我在跟踪 this example .

以下是我迄今为止所做的:

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    TextView textView = (TextView) findViewById(R.id.textView);
    SeekBar seekBar = (SeekBar) findViewById(R.id.seekBar);
    seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            TextView textView = (TextView) findViewById(R.id.textView);
            textView.setText("Number of variables: " + String.valueOf(progress));
        }
    });
}

我得到一个错误:

无法解析符号“setOnSeekBarChangeListener”

我见过 this post

编辑: 将变量和侦听器移到 onCreate()

1 回复 | 直到 5 年前

Cyber Gh 5 年前

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        TextView textView = (TextView) findViewById(R.id.textView);
        SeekBar seekBar = (SeekBar) findViewById(R.id.seekBar);
        seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                TextView textView = (TextView) findViewById(R.id.textView);
                textView.setText("Number of variables: " + String.valueOf(progress));
            }
            @Override
            public void onStartTrackingTouch(SeekBar seekBar){

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {

            }

        });

    }
}